Pharmaceutical Sciences Notes

NTA Level 5 • Semester 1 • PST05106 Alkanes of Pharmaceutical Importance Pharmaceutical Organic Chemistry • Source Session/Topic 8 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 8: Alkanes of Pharmaceutical Importance. Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define alkanes • List alkanes and their isomers • Explain nomenclature of alkanes • Draw chemical structure of alkanes • List chemical properties of alkanes • Explain chemical reactions of alkanes Resources Needed: • Flip charts, marker pens, and masking tape. • Black/white board and chalk/whiteboard markers. SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of Alkanes | | | |Presentation | | |3 |15 minutes |Buzzing |Alkanes and their Isomers | | | |Presentation | | |4 |15 minutes |Presentation |Nomenclature of Alkanes | |5 |15 minutes |Presentation |Chemical Structure of Alkanes | |6 |10 minutes |Brainstorming |Chemical Properties of Alkanes | | | |Presentation | | |7 |30 minutes |Group |Chemical Reactions and Uses of | | | |discussion |Alkanes | | | |Presentation | | |8 |10 minutes |Presentation |Key Points | |9 |10 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Definition of Alkanes (10 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is Alkane? | | | |ALLOW few students to respond. | | | |WRITE their responses on the flip chart/ board. | | | |CLARIFY and SUMMARISE by using the content below; | • Alkane or Paraffin is an acyclic saturated hydrocarbon composed of only carbons and hydrogen atoms and contain carbon-carbon single bonds. • Compounds that contain only carbon and hydrogen are called hydrocarbons. Homologous series (homo is Greek for “the same as”) is a family of compounds in which each member differs from the next by one methylene group (CH2). • The general molecular formula for an alkane is CnH2n+2 where n is an integer. • Members (CnH2n+2) o Methane CH4 o Ethane C2H6 o Propane C3H8 o Butane C4H10 o Pentane C5H12 o Hexane C6H14 o Heptane C7H16 o Octane C8H18 o Nonane C9H20 o Decane C10H22 o Undecane C11H24 etc • So, if an alkane has one carbon atom, it must have four hydrogen atoms; if it has two carbon atoms, it must have six hydrogen. NOTE; Only one possible structure for an alkane with molecular formula CH4 (methane) and molecular formula C2H6 (ethane) • There are two possible structures for an alkane straight-chain and a branched structure. • Both of these structures fulfill the requirement that each carbon forms four bonds and each hydrogen forms only one bond. STEP 3: Alkanes and their Isomers (15 minutes). |Activity: Buzzing (5minutes) | | | |ASK students to pair up and buzz on the following question for 5 | |minutes. | | | |What is an isomer? | |What is isomerism? | |ALLOW pairs to respond on the question. | | | |WRITE their response on the flip chart/board. | | | |CLARIFY and SUMMARIZE by using the content below | • Isomers Refers to different compounds having the same molecular formula but different structural formula (have different arrangements of atoms in space). • In n-alkanes, no carbon is bonded to more than two other carbons, give rise to a linear chain. • When carbon is bonded to more than two other carbons, a branched is formed. Example.1; C6H14 has 5 isomers as follows: o Hexane o 2-Methylpentane o 3-Methylpentane o 2,2-Dimethylbutane o 2,3-Dimethylbutane Example.2; C7H16 has 9 isomers as follows: o Heptane o 2-Methylhexane o 3-Methylhexane o 2,2-Dimethylpentane o 2,3-Dimethylpentane o 2,4-Dimethylpentane o 3,3-Dimethylpentane o 3-Ethylpentane o 2,2,3-Trimethylbutane Example 3; C5H12 has 3 isomers which are: o Pentane o 2-Methylbutane o 2,2-Dimethylpropane Example 4; C4H10 has 2 isomers which are; o Butane o 2-Methylpropane STEP 4: Nomenclature of Alkanes (15 Minutes). • Rule1. Determine the longest continuous carbon chain. o This chain is called the parent hydrocarbon. • Rule 2. In isomeric compounds (II and III), indicate by a number the Carbon to which the alkyl group is attached. • Rule 3. In numbering the parent chain, start at whichever end resulting in the use of the lowest numbers; thus, II is called 2–‐ methylpentane rather than 4–‐ methylpentane. • Rule 4. If the same alkyl group occurs more than once as a side chain, indicate this by the prefix di-, tri-, tetra- etc., to show how many of these alkyl groups are there and indicate by various numbers the position of each group, as in 2,2,4‐trimethyl-pentane. [pic] • Rule 5 If there are several different alkyl groups attached to the parent chain, name them in alphabetical order, as in 3,3‐diethyl-5- isopropyl-4-methyloctane [pic] STEP 5: Chemical Structure of Alkanes (15 minutes). • All acyclic alkanes (unbranded and branched) have the characteristic molecular formula CnH2n+2, where n is the number of carbon atoms in the chain. • Gives the molecular formulas and Lewis structure for the unbranched and n-alkanes (n stands for normal) [pic] STEP 6: Chemical Properties of Alkanes (10 minutes). |Activity: Brainstorming (5minutes) | | | |ASK students to pair up and brainstorm on the following question for 5 | |minutes. | | | |What are the chemical properties of Alkanes? | | | |ALLOW pairs to respond on the question | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content in the table 1 below | • Combustion o Complete combustion (Under sufficient amount of oxygen (Air)) any hydrocarbon produces carbon

NTA Level 5 • Semester 1 • PST05106 Alkenes of Pharmaceutical Importance Pharmaceutical Organic Chemistry • Source Session/Topic 9 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 9: Alkenes of Pharmaceutical Importance. Total Session Time: 120 minutes Prerequisites None Learning Tasks By the end of this session students are expected to be able to: • Define alkenes • List alkenes and their isomers • Explain nomenclature of alkenes • Draw chemical structure of alkenes • List chemical properties of alkenes • Explain chemical reactions of alkenes Resources Needed: • Flip charts, marker pens, and masking tape. • Black/white board and chalk/whiteboard markers. SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of Alkenes | | | |Presentation | | |3 |15 minutes |Buzzing |Alkenes and their Isomers | | | |Presentation | | |4 |15 minutes |Presentation |Nomenclature of Alkenes | |5 |15 minutes |Presentation |Chemical Structure of Alkenes | |6 |10 minutes |Presentation |Chemical Properties of Alkenes | | | |Brainstorming | | |7 |40 minutes |Group |Chemical Reactions and Uses of | | | |discussion |Alkenes | | | |Presentation | | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | SESSION CONTENTS. STEP 1: Presentation of Session Title and Learning Tasks (5 minutes). READ or ASK students to read the learning tasks and clarify. ASK students if they have any questions before continuing. STEP 2: Definition of Alkenes (5 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are Alkenes? | | | |ALLOW few students to respond. | | | |WRITE their responses on the flip chart/ board. | | | |CLARIFY and SUMMARISE by using the content below | • These are unsaturated hydrocarbons, they contain two less hydrogen atoms as compared to corresponding alkanes (sp2 hybrid), also known as OLEFINS or ALKYLENES, general formula: (CnH2n). • They contain carbon-carbon double bond, this is the distinguishing feature of the alkenes. • The simplest member of the alkene family is ethylene C2H2. STEP 3: Alkenes and their Isomers (15 minutes). |Activity: Buzzing (10minutes) | | | |ASK students to pair up and buzz on the following question for 5 | |minutes. | | | |What is the isomer of Alkenes? | | | |ALLOW pairs to respond on the question. | | | |WRITE their response on the flip chart/board. | | | |CLARIFY and SUMMARIZE by using the content in the table 1 below | Geometric isomerism • Arises due to restricted rotation at the C-C double bonds • Occurs only when two atoms/groups attached to each carbon of the double bond are different from one another • The cis-isomer has like groups on the same side of the double bond, whereas the trans-isomer has like group on opposite sides of the double bond Example, [pic] Cis Butene (the methyl groups are on the same side) [pic] Trans Butene (the methyl groups are on the opposite side) Structural isomerism • Isomers which have the atoms of their molecules linked in a different order • This can come about in one of three ways: o Chain Isomerism [pic] [pic][pic] ▪ Chain isomers of the same compound are very similar. ▪ There may be small difference in physical properties such as melting or boiling point due to different strengths of intermolecular bonding. ▪ Their chemistry is likely to be identical. o Positional Isomers [pic] [pic] ▪ Positional isomers are also usually similar. ▪ There are slight physical differences, but the chemical properties are usually very similar. ▪ However, occasionally, positional isomers can have quite different properties Example of isomerism is given by propanol • It has the formula C3H8O (or C3H7OH) and two isomers propan-1-ol (n-propyl alcohol; I) and propan-2-ol (isopropyl alcohol; II) • Note that the position of the oxygen atom differs between the two: it is attached to an end carbon in the first isomer, and to the center carbon in the second. • The number of possible isomers increases rapidly as the number of atoms increases; For example; the next largest alcohol, named butanol (C4H10O), has four different structural isomers. [pic] [pic] STEP 4: Nomenclature of Alkenes (15 minutes). • The IUPAC Rules are similar to those of alkanes, but few new rules must be added to name and locate the double bond. o Rule 1: Select as the parent structure the longest continuous chain that contains the C-C double bond: ▪ C-C double bonds are designated by the ending -ene, if more than one double bond is present, the ending is diene, triene, tetraene, etc. o Rule 2: Indicate by a number the position of the double bond in the chain. Number it so that the C-atoms in the double bond have the lowest possible numbers. o Rule 3: The position of the double bond(s) is indicated by the number(s) of the lower numbered carbon atom of each double bond. These numbers are placed in front of the name of the compound. Example, [pic] o Rule 4: In cyclic hydrocarbons, start numbering around the ring with the carbons of the double bond indicates by numbers the positions of alkyl groups attached to the parent chain. Example, [pic] 3-Methylcyclopenten Table 1. Nomenclature of simple alkenes |COMPOUND |COMMON NAME |IUPAC NAME | |CH2=CH2 |Ethylene |Ethene | |CH3CH=CH2 |Propylene |1-Propene | |CH3CH2CH=CH2 |α-Butylene |1-Butene | |CH3C(CH3)=CH2 |Isobutylene |2-Methylpropene | |CH2=C(C2H5)CH2CH3 |- |2-Ethyl-1-butene | |CH2=CHCl |Vinyl chloride |Chloroethene | |CH2=CHCH2Cl |Allyl chloride |3-Chloropropene | |CH3=CHCH=CH2 | |1,3-Butadiene | STEP 5: Chemical Structure of Alkenes (15 minutes). Definition • The arrangement of chemical bonds between atoms in a molecule (or in an iron or radical with multiple atoms) especially which atoms are chemically bonded to what other atoms with what kind of chemical bonds, together with

NTA Level 5 • Semester 1 • PST05106 Alkynes of Pharmaceutical Importance Pharmaceutical Organic Chemistry • Source Session/Topic 10 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 10: Alkynes of Pharmaceutical Importance. Total Session Time: 120 minutes Prerequisites None Learning Tasks By the end of this session students are expected to be able to: • Define alkynes • List alkynes and their isomers • Explain nomenclature of alkynes • Draw chemical structure of alkynes • List physical properties of alkynes • Explain chemical reactions of alkynes Resources Needed: • Flip charts, marker pens, and masking tape. • Black/white board and chalk/whiteboard markers. SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of Alkynes | | | |Presentation | | |3 |15 minutes |Buzzing |Alkynes and their Isomers | | | |Presentation | | |4 |15 minutes |Presentation |Nomenclature of Alkynes | |5 |15 minutes |Presentation |Chemical Structure of Alkynes | |6 |10 minutes |Brainstorming |Physical Properties of Alkynes | | | |Presentation | | |7 |40 minutes |Group |Chemical Reactions involving Alkynes| | | |discussion | | | | |Presentation | | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | SESSION CONTENTS. STEP 1: Presentation of Session Title and Learning Tasks (5 minutes). READ or ASK students to read the learning tasks and clarify. ASK students if they have any questions before continuing. STEP 2: Definition of Alkynes (10 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are Alkynes? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • These are unsaturated hydrocarbons, they contain four less hydrogen atoms as compared to corresponding alkanes, also known as Acetylenes, general formula: (CnH2n-2). • They contain carbon-carbon triple bond, this is the distinguishing feature of the alkynes. • The simplest member of the alkyne family is ethylene C2H2. STEP 3: Alkynes and their Isomers (15 minutes). |Activity: Buzzing (10minutes) | | | |ASK students to pair up and buzz on the following question for 5 | |minutes. | | | |What are the isomers of Alkynes? | | | |ALLOW pairs to respond on the question. | | | |WRITE their response on the flip chart/board. | | | |CLARIFY and SUMMARIZE by using the content in the table 1 below | Structural isomerism • Isomers which have the atoms of their molecules linked in a different order • This can come about in one of three ways: o Chain Isomerism. ▪ Chain isomers of the same compound are very similar. ▪ There may be small difference in physical properties such as melting or boiling point due to different strengths of intermolecular bonding. ▪ Their chemistry is likely to be identical. o Positional Isomer ▪ Positional isomers are also usually similar. ▪ There are slight physical differences, but the chemical properties are usually very similar. ▪ However, occasionally, positional isomers can have quite different properties STEP 4: Nomenclature of Alkynes (15 minutes). • The IUPAC Rules are similar to those of alkanes, but few new rules must be added to name and locate the triple bond. o Rule 1: Select as the parent structure the longest continuous chain that contains the C-C triple bond: ▪ C-C triple bonds are designated by the ending -yne, if more than one triple bond is present, the ending is diyne, triyne, tetrayne, etc. o Rule 2: Indicate by a number the position of the triple bond in the chain. Number it so that the C-atoms in the triple bond have the lowest possible numbers. o Rule 3: The position of the triple bond(s) is indicated by the number(s) of the lower numbered carbon atom of each triple bond. These numbers are placed in front of the name of the compound. Examples o [pic] [pic] o [pic][pic] o [pic][pic] o Rule 4: In cyclic hydrocarbons, start numbering around the ring with the carbons of the double bond indicates by numbers the positions of alkyl groups attached to the parent chain. STEP 5: Chemical Structure of Alkynes (15 minutes). • The sigma bond is sp-sp overlap [pic] • The two pi bonds are unhybridized p overlaps at 90(, which blend into a cylindrical shape. [pic] • Bond Lengths • More s character, so shorter length than alkenes or alkanes.Three bonding overlaps, so shorter [pic] [pic] • Acidity Table [pic] Table 2: Chemical stuctures of alkynes CnH2n-2 | IUPAC Name | Molecular Formula |Condensed Structural | | | |Formula | |Ethyne |C2H2 |CHCH | |Propyne |C3H4 |CHCCH3 | |1-butyne |C4H6 |CHCCH2CH3 | |1-pentyne |C5H8 |CHC(CH2)2CH3 | |1-hexyne |C6H10 |CHC(CH2)3CH3 | |1-heptyne |C7H12 |CHC(CH2)4CH3 | |1-octyne |C8H14 |CHC(CH2)5CH3 | STEP 6: Physical Properties of Alkynes (10 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are physical properties of Alkynes? | | | |ALLOW few students to respond. | | | |WRITE their responses on the flip chart/ board. | | | |CLARIFY and SUMMARISE by using the content below | • Nonpolar, insoluble in water • Soluble in most organic solvent • Boiling points similar to alkane of same size • Less dense than water • Up to 4 carbons, gas at room temperature STEP 7: Chemical Reactions involving Alkynes (40 minutes). |Activity: Small Group Discussion (20 minutes) | | | |DIVIDE students into small groups. | | | |ASK students to discuss in groups on the following questions | |What are the chemical properties of Alkanes? | | | |[pic]REFER Students to Book | | | |ALLOW students to discuss for 15 minutes. | | | |ALLOW each group to present

NTA Level 5 • Semester 1 • PST05106 Alcohols of Pharmaceutical Importance Pharmaceutical Organic Chemistry • Source Session/Topic 11 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 11: Alcohols of Pharmaceutical Importance. Total Session Time: 120 minutes Prerequisites None Learning Tasks By the end of this session students are expected to be able to: • Define alcohols • List alcohols and their isomers • Explain nomenclature of alcohols • Draw chemical structure of alcohols • List chemical properties of alcohols • Explain chemical reactions of alcohols Resources Needed: • Flip charts, marker pens, and masking tape. • Black/white board and chalk/whiteboard markers. SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of Alcohols | | | |Presentation | | |3 |15 minutes |Presentation |Alcohols and their Isomers | |4 |15 minutes |Presentation |Nomenclature of Alcohols | |5 |15 minutes |Presentation |Chemical Structure of Alcohols | |6 |15 minutes |Presentation |Chemical Properties of Alcohols | | | |Buzzing | | |7 |35 minutes |Group |Chemical Reactions involving | | | |discussion |Alcohols | | | |Presentation | | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | SESSION CONTENTS. STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Definition of Alcohols (10 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are Alcohols? | | | |ALLOW few students to respond. | | | |WRITE their responses on the flip chart/ board. | | | |CLARIFY and SUMMARISE by using the content below | • Alcohols are a family of organic compounds containing a hydroxyl (OH) group bonded to an sp3 hybridized carbon atom. • The general formula is CnH(2n+1)OH or R-OH. • Alcohols are named in similar manner as in alkenes except that the suffix –e from alkanes is replace by –ol. • Alcohols are classified into three groups: primary, secondary, and tertiary, depending on the carbon atom bonded to the – OH group. • If the carbon atom is primary (bonded to one other carbon atom), the compound is a primary alcohol. • If the OH group is attached to a carbon atom that is joined to two other carbon atoms, it is a secondary alcohol, and the carbon atom to which it is attached is a secondary carbon atom. • If the OH group is attached to a carbon atom that is joined to three other carbon atoms, it is a tertiary alcohol, and the carbon atom to which it is attached is a tertiary carbon atom. Primary alcohols [pic] [pic] [pic] STEP 3: Alcohols and their Isomers (15 Minutes). • Alcohols exhibit following three types of isomerism. o Chain isomerism. o Position isomerism. o Functional isomerism. Chain isomerism • Alcohols containing at least 4-carbon atoms form chain isomerism due to the different structure of C-skeleton in the longest chain. [pic] Position isomerism • Alcohols containing at least 3 C atoms form position isomerism due to a different position of a hydroxyl group (OH). Example [pic] Functional isomer • Alcohols containing at least 2 carbon atoms give functional isomers. The functional isomer of an alcohol is ether. Example [pic] STEP 4: Nomenclature of Alcohols (15 minutes). • The IUPAC system provides unique names for alcohols, based on rules that are similar to those for other classes of compounds. • In general, the name carries the -ol suffix, together with a number to give the location of the hydroxyl group Rules 1. Select the longest continuous carbon atom chain containing the carbinol (hydroxyl) group(s). 2. Number the chain, giving the hydroxyl (alcohol) substituent(s) the lowest number possible. 3. Name the longest chain as an alkane, but drop the terminal -e and add -ol. Ethane would become ethanol. 4. For monohydric alcohols the letter ‘-e’ at the end of the root name is replaced by the ending ‘-ol’ with a number, when necessary, to show the position of the –OH group on the carbon skeleton. [pic] 5. If more than one hydroxyl group is present (for polyols i.e. dihydric,trihydric etc.) the name becomes -diol, -triol, etc. and the terminal -e in the parent name is not dropped from the alkane name. But the letters ‘diol’ ‘triol’ etc & numbers 1,2,3 etc are added to the ending to show how many –OH groups & their position • For example ethane with two hydroxyl groups would become ethanediol. • Since the hydroxyl groups could be on or different carbon atoms, one needs to specify where the hydroxyl groups are attached. • The name would be 1,2-ethanediol if the hydroxyl groups are on adjacent (vicinal) carbon atoms. • Updated nomenclature rules suggest that the position of substituent attachment should precede the functional group name, e.g., ethane-1,2- diol rather than 1,2-ethanediol. 6. Indicate by numbers the positions of other groups attached to the parent chain • OH group takes priority (even over -ene or -yne) [pic] • Considering the example below: [pic] • The complete IUPAC name is 1-bromo-3,3-dimethyl-2-butanol. • The new IUPAC positioning of numbers would place the 2 next to the group it locates (-ol), giving the name 1-bromo-3,3-dimethylbutan-2- ol. 7. Cyclic alcohols are named using the prefix cyclo-; the hydroxyl group is assumed to be on carbon number 1, C1. [pic] [pic] STEP 5: Chemical Structure of Alcohols (15 minutes). • Alcohols fall into different classes depending on how the -OH group is positioned on the chain of carbon atoms. There are some chemical differences between the various types. Primary alcohols • In a primary (1°) alcohol, the carbon atom that carries the -OH group is only attached to one alkyl group. Some examples of

NTA Level 5 • Semester 1 • PST05106 Carboxylic Acids of Pharmaceutical Importance Pharmaceutical Organic Chemistry • Source Session/Topic 12 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 12: Carboxylic Acids of Pharmaceutical Importance. Total Session Time: 120 minutes Prerequisites • None Learning Tasks. By the end of this session students are expected to be able to: • Define carboxylic acids • Explain nomenclature of carboxylic acids • Draw chemical structure of carboxylic acids • List chemical properties of carboxylic acids • Explain chemical reactions of carboxylic acids Resources Needed: • Flip charts, marker pens, and masking tape. • Black/white board and chalk/whiteboard markers. SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of Carboxylic Acids | | | |Presentation | | |3 |15 minutes |Presentation |Nomenclature of Carboxylic Acids | |4 |15 minutes |Presentation |Chemical Structure of Carboxylic | | | | |Acids | |5 |15 minutes |Buzzing |Chemical Properties of Carboxylic | | | |Presentation |Acids | |6 |40 minutes |Group |Chemical Reactions involving | | | |discussion |Carboxylic Acids | | | |Presentation | | |7 |10 minutes |Presentation |Key Points | |8 |10 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Definition of Carboxylic Acids (10 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is carboxylic acid? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • The combination of a carbonyl group and a hydroxyl on the same carbon atom is called a carboxyl group. • Compounds containing the carboxyl group are distinctly acidic and are called carboxylic acids. [pic] Condensed structures [pic] • Therefore, carboxylic acids are acidic organic compounds containing the carboxyl group as a functional group, attached to hydrogen HCOOH or an alkyl group as RCOOH or an aryl group as ArCOOH • The general formula would be CnH(2n+1)COOH or R-CO2H. STEP 3: Nomenclature of Carboxylic Acids (15 minutes). IUPAC Names • The IUPAC nomenclature for carboxylic acids uses the name of the alkane that corresponds to the longest continuous chain of carbon atoms. • The final -e in the alkane name is replaced by the suffix -oic acid. • The chain is numbered, starting with the carboxyl carbon atom, to give positions of substituents along the chain. In naming, the carboxyl group takes priority over any of the functional groups discussed previously =Examples [pic] [pic] [pic] [pic] [pic] [pic] [pic] [pic] Some more examples of traditional names most widely used are: • Formic acid- HCOOH • Acetic acid – CH3COOH • Propionic acid – CH3CH2COOH • Butyric acid – CH3(CH2)2COOH • Valeric acid – CH3(CH2)3COOH • Caproic acid – CH3(CH2)4COOH • Capyrylic acid – CH3(CH2)6COOH • Capric acid – CH3(CH2)8COOH STEP 4: Chemical Structure of Carboxylic Acids (15 minutes) • The CO2H unit is planar and consistent with sp2 hybridization and a resonance interaction of the lone pairs of the hydroxyl oxygen with the π system of the carbonyl. | Carboxylic Acid | | | | |Structure | | |Ethanoic acid |CH3CO2H | | |Propanoic acid |CH3CH2CO2H | | |Fluoroethanoic acid |CH2FCO2H | | |Chloroethanoic acid |CH2ClCO2H | | |Dichloroethanoic acid |CHCl2CO2H | | |Trichloroethanoic acid |CCl3CO2H | | |Nitroethanoic acid |O2NCH2CO2H | | STEP 5: Chemical Properties of Carboxylic Acids (15 minutes). |Activity: Buzzing (10minutes) | | | |ASK students to pair up and buzz on the following question for 5 | |minutes | | | |What are the chemical properties of carboxylic acid? | | | |ALLOW pairs to respond on the question | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content in the table 1 below | The following are chemical properties of carboxylic acids; Acidity of Carboxylic Acids Carboxylic acids are weak acids and their carboxylic anions are strong conjugate bases are slightly alkaline due to the hydrolysis of carboxylate anion compared to other species, the order of acidity and basicity or corresponding conjugate bases are as follows: Acidity RCOOH > HOH > ROH > HC[pic] CH > NH3 > RH Basicity RCOO– < HO– < RO– < HCC– < NH2-< R– Reaction of Carboxylic Acids with Metals • The carboxylic acids react with metals to liberate hydrogen and are soluble in both NaOH and NaHCO3 solutions. For example; ▪ 2CH3COOH + 2Na → 2CH3COO–Na+ + H2 ▪ CH3COOH + NaOH → CH3COO–Na+ + H2O ▪ CH3COOH + NaHCO3 → CH3COO–Na+ + H2O + CO2 • Carboxylic acids dissociate in water to give resonance stabilised carboxylate anions and hydronium ion. [pic] Effect of substituents on the acidity of Carboxylic Acids • Any factor that stabilizes the anion more than it stabilizes the acid would increase the acidity of carboxylic acids. • While any factor that decreases the stability of anion would decrease the acidity of carboxylic acids. • Electron withdrawing groups disperse the negative charge and thus stabilize the anion which results in increase in acidity of the carboxylic acids. • Electron donating groups intensify the negative charge and destabilize the anion which results in decrease in acidity of carboxylic acid. [pic] Conversion of Carboxylic Acids into functional derivatives • Carboxylic acids can be converted into number of other compounds (known as derivatives of carboxylic acids or simply acid derivatives) by replacement of its –OH group by a Cl, OR or NH2 . o Replacement of -OH by -Cl forms acid chlorides. o Replacement of -OH by -OR forms ester. o Replacement of -OH

NTA Level 5 • Semester 1 • PST05106 Esters of Pharmaceutical Importance Pharmaceutical Organic Chemistry • Source Session/Topic 13 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 13: Esters of Pharmaceutical Importance. Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define esters • Explain nomenclature of esters • Draw chemical structure of esters • List chemical properties of esters • Explain chemical reactions of esters Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of Esters | | | |Presentation | | |3 |15 minutes |Presentation |Nomenclature of Esters | |4 |15 minutes |Presentation |Chemical Structure of Esters | |5 |20 minutes |Buzzing |Chemical Properties of Esters | | | |Presentation | | |6 |40 minutes |Group |Chemical Reactions involving Esters | | | |discussion | | | | |Presentation | | |7 |05 minutes |Presentation |Key Points | |8 |10 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify. ASK students if they have any questions before continuing. STEP 2: Definition of Esters (10 minutes) |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is Ester? | | | |ALLOW few students to respond. | | | |WRITE their responses on the flip chart/ board. | | | |CLARIFY and SUMMARISE by using the content below | • An ester (“carboxylic ester” in the textbook) is a derivative of a carboxylic acid in which there is a carbon group connected to the single- bonded oxygen: • In an ester, The H in the carboxyl group is replaced with an alkyl group. [pic] [pic] Some common esters are as follows; [pic] STEP 3: Nomenclature of Esters (15 minutes). • Name the alkyl or aromatic portion contributed by the “alcohol part” first. [pic] • The “acid part” is named as a carboxylic acid, with the -ic acid suffix changed to -ate [pic] [pic] STEP 4: Chemical Structure of Esters (15 minutes). • Esters contain a carbonyl center, which gives rise to 120-degree C-C-O and O-C-O bond angles due to sp2 hybridization. • Unlike amides, esters are structurally flexible functional groups because rotation about the C-O-C bonds has a lower energy barrier. • Their flexibility and low polarity affect their physical properties on a macroscopic scale. • They tend to be less rigid, leading to a lower melting point, and more volatile, leading to a lower boiling point, than the corresponding amides. • The pKa of the alpha-hydrogens, or the hydrogens attached to the carbon adjacent to the carbonyl, on esters is around 25, making them essentially non-acidic except in the presence of very strong bases. [pic] • An ester is characterized by the orientation and bonding of the atoms shown, where R and R’ are both carbon-initiated chains of varying length, also known as alkyl groups. • As usual, R and R’ are either alkyl groups or groups initiating with carbon. • Esters are derivative of carboxylic acids where the hydroxyl (OH) group has been replaced by an alkoxy (O-R) group. • They are commonly synthesized from the condensation of a carboxylic acid with an alcohol. STEP 5: Chemical Properties of Esters (20 minutes). |Activity: Buzzing (5minutes) | | | |ASK students to pair up and buzz on the following question for 5 | |minutes | | | |What are the chemical properties of Esters? | | | |ALLOW pairs to respond on the question | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content in the table 1 below | In acid hydrolysis • An ester reacts with water to produce a carboxylic acid and an alcohol. • An acid catalyst is required. [pic] Base hydrolysis Base hydrolysis is the reaction of an ester with a strong base. Produces the salt of the carboxylic acid and an alcohol. [pic] STEP 6: Chemical Reactions involving Esters (40 minutes). |Activity: Small Group Discussion (15 minutes) | | | |DIVIDE students into small groups | | | |ASK students to discuss in groups on the following questions | |What are the chemical reactions involving Esters? | | | |[pic]REFER Students to Book | | | |ALLOW students to discuss for 10 minutes | | | |ALLOW each group to present for 5 minutes | | | |CLARIFY and SUMMARIZE by using the contents below | Esterification Reaction • The simplest way to synthesize an ester is to heat a carboxylic acid with an alcohol or phenol (plus an acid catalyst). o The oxygen of the alcohol adds to the carboxyl group, splitting out a molecule of water in the process (an esterification reaction). [pic] • Since this reaction is a reversible reaction, it often reaches an equilibrium with a large amount of unreacted starting material still present. • Better yields are obtained using either acid chlorides or acid anhydrides as starting materials. o These reactions are nonreversible [pic] Examples [pic] Ester Hydrolysis • Esters may be broken apart under acidic conditions by water (a hydrolysis reaction) to form a carboxylic acid and an alcohol. [pic] • This is essentially the reverse reaction of the synthesis of esters from carboxylic acids and alcohols. Base hydrolysis (Saponification) Esters may be broken apart under basic conditions by sodium hydroxide (lye) or potassium hydroxide to form carboxylate salts and alcohols. [pic] This reaction is important in the production of soaps STEP 8: Key Points (05 minutes) • An ester is a chemical compound derived from carboxylic acid in which

NTA Level 5 • Semester 1 • PST05106 Acyl Chlorides of Pharmaceutical Importance Pharmaceutical Organic Chemistry • Source Session/Topic 14 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 14: Acyl Chlorides of Pharmaceutical Importance. Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define acyl chlorides • Explain nomenclature of acyl chlorides • Explain physical properties of acyl chlorides • Describe the preparation of acyl chlorides • Explain chemical reactions of acyl chlorides Resources Needed: • Flip charts, marker pens, and masking tape • Black/white board and chalk/whiteboard markers SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of acyl chlorides | | | |Presentation | | |3 |15 minutes |Presentation |Nomenclature of acyl chlorides | |4 |15 minutes |Presentation |Physical Properties of Acyl | | | | |Chlorides | |5 |20 minutes |Buzzing |Preparation of Acyl Chlorides | | | |Presentation | | |6 |40 minutes |Group |Chemical Reactions involving acyl | | | |discussion |chlorides | | | |Presentation | | |7 |05 minutes |Presentation |Key Points | |8 |10 minutes |Presentation |Evaluation | SESSION CONTENTS STEP 1: Presentation of Session Title and Learning Tasks (5 minutes). READ or ASK students to read the learning tasks and clarify. ASK students if they have any questions before continuing. STEP 2: Definition of Acyl Chlorides (10 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | |What are acyl chlorides? | | | |ALLOW few students to respond. | | | |WRITE their responses on the flip chart/ board. | | | |CLARIFY and SUMMARISE by using the content below | • Acyl chlorides as "acid derivatives". • A carboxylic acid such as ethanoic acid has the structure: [pic] • There are a number of related compounds in which the -OH group in the acid is replaced by something else. • Compounds like this are described as acid derivatives. • Acyl chlorides (also known as acid chlorides) are one example of an acid derivative. • In this case, the -OH group has been replaced by a chlorine atom. [pic] STEP 3: Nomenclature of Acyl Chlorides (15 minutes). • The easiest way of thinking about the names is to see the relationship with the corresponding. |carboxylic acid |acyl chloride |acyl chloride | |name |name |formula | |ethanoic acid |ethanoyl |CH3COCl | | |chloride | | |propanoic acid |propanoyl |CH3CH2COCl | | |chloride | | |butanoic acid |butanoyl |CH3CH2CH2COCl | | |chloride | | • The acyl group name is derived from the carboxylic acid name by replacing -oic acid by -ly. • If you have something substituted into the hydrocarbon chain, the carbon in the -COCl group counts as the number 1 carbon. • For example, 2-methylbutanoyl chloride is: [pic] • Note: Hardly anyone ever mentions methanoyl chloride, HCOCl – derived from methanoic acid. • That is because methanoyl chloride is very unstable, decomposing to give carbon monoxide and HCl. STEP 4: Physical properties of acyl chlorides (15 minutes). • Appearance o An acyl chloride like ethanoyl chloride is a colourless fuming liquid. o The strong smell of ethanoyl chloride is a mixture of the smell of vinegar (ethanoic acid) and the acrid smell of hydrogen chloride gas. o The smell and the fumes are because ethanoyl chloride reacts with water vapour in the air. • Solubility in water o Acyl chlorides can't be said to dissolve in water because they react (often violently) with it. o The strong reaction means that it is impossible to get a simple aqueous solution of an acyl chloride. • Boiling points o Taking ethanoyl chloride as typical: o Ethanoyl chloride boils at 51°C. o It is a polar molecule, and so has dipole-dipole attractions between its molecules as well as van der Waals dispersion forces. o However, it doesn't form hydrogen bonds. o Its boiling point is therefore higher than, say, an alkane of similar size (which has no permanent dipoles), but not as high as a similarly sized alcohol (which forms hydrogen bonds in addition to everything else.) STEP 5: Preparation of Acyl Chlorides (20 minutes). |Activity: Buzzing (5minutes) | | | |ASK students to pair up and buzz on the following question for 5 | |minutes. | |How are acyl chlorides prepared? | | | |ALLOW pairs to respond on the question. | | | |WRITE their response on the flip chart/board. | | | |CLARIFY and SUMMARIZE by using the content in the table 1 below | • Acyl chlorides are prepared by treatment of carboxylic acids with thionyl (SOCl2). [pic] • Example, [pic] STEP 6: Chemical Reactions involving acyl chlorides (40 minutes). |Activity: Small Group Discussion (15 minutes) | | | |DIVIDE students into small groups | | | |ASK students to discuss in groups on the following questions | |What are the chemical reactions involving Esters? | |[pic]REFER Students to Book | |ALLOW students to discuss for 10 minutes | | | |ALLOW each group to present for 5 minutes | | | |CLARIFY and SUMMARIZE by using the contents below | • Substitution of the chlorine atom by other groups o Acyl chlorides are extremely reactive, and in their reactions the chlorine atom is replaced by other groups. o In each case, in the first instance, hydrogen chloride gas is produced as steamy acidic fumes. o However, in some cases the hydrogen chloride goes on to react with one of the substances in the reaction mixture. o Taking ethanoyl chloride as typical, the initial reaction is of this kind: [pic][pic] o The reactions involve compounds like water, alcohols and phenols, or ammonia and amines. o All of these particular cases contain a very electronegative element with an active lone

NTA Level 5 • Semester 1 • PST05106 Ethers of Pharmaceutical importance Pharmaceutical Organic Chemistry • Source Session/Topic 15 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 15: Ethers of Pharmaceutical importance. Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define ethers • List ethers and their isomers • Explain nomenclature of ethers • Draw chemical structure of ethers • List chemical properties of ethers • Explain chemical reactions of ethers Resources Needed: • Flip charts, marker pens, and masking tape. • Black/white board and chalk/whiteboard markers. SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of Ethers | | | |Presentation | | |3 |10 minutes |Presentation |Ethers and their Isomers | |4 |15 minutes |Presentation |Nomenclature of Ethers | |5 |15 minutes |Presentation |Chemical Structure of Ethers | |6 |15 minutes |Buzzing |Chemical Properties of Ethers | | | |Presentation | | |7 |35 minutes |Group |Chemical Reactions involving Ethers | | | |discussion | | | | |Presentation | | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | SESSION CONTENTS. STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Definition of Ethers (10 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are Ethers? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | • Ethers are compounds of formula R – 0 – R ', where R and R' may be alkyl groups or aryl (benzene ring) groups. • Ethers can be considered derivatives of water (HOH) or alcohols (ROH) by replacing an H with an R group. • In an alcohol, one hydrogen atom of water is replaced by an alkyl group. • In an ether, both hydrogens are replaced by alkyl groups. [pic] • The R groups in ethers can be alkyl, aryl, or alkenyl. • The R groups can be the same or different. • If the R groups are the same, the ethers are called symmetrical ethers. • If the R groups are different, the ethers are called unsymmetrical ethers. • Ethers can be cyclic or acyclic. • Rings that contain an atom other than carbon are called heterocyclic compounds. • Oxygen is the heteroatom in cyclic ethers. Examples of ethers [pic] • The most important commercial ether is diethyl ether, often called "ethyl ether’’, or simply "ether." STEP 3: Ethers and their Isomers (10 minutes). Aliphatic Ethers can give two different types of isomers. • Chain isomerism o Ethers with the same formula and having different carbon chain skeletons are called chain isomers. o Examples: [pic] • Functional isomers. o Ethers are isomeric with alcohols. o Example: [pic] is isomeric with ethyl alcohol C2H5OH • Metamerism o Isomers with the same molecular formula but different alkyl groups (around the functional group) are called metamers. An ether with formula C4H10O has 3 metamers. [pic] STEP 4: Nomenclature of Ethers (15 minutes). • The IUPAC system, generally used with more complicated ethers, is sometimes called the alkoxy alkane system. • The common nomenclature of ethers, which is sometimes called the alkyl alkyl ether system has also been widely used • IUPAC names use the more complex alkyl group as the root name, and the rest of the ether as an alkoxy group. • For example, cyclohexyl methyl ether is named methoxycyclohexane. • This systematic nomenclature is often the only clear way to name complex ethers. Example, [pic] [pic] |Table 1: Common Alkyl and Alkoxy Groups | |Alkyl Group |Name | |Alkoxy Group |Name | |CH3– |Methyl | |CH3O– |Methoxy | |CH3CH2– |Ethyl | |CH3CH2O– |Ethoxy | |(CH3)2CH– |Isopropyl | |(CH3)2CHO– |Isopropoxy | |(CH3)3C– |tert-Butyl | |(CH3)3CO– |tert-Butoxy | |C6H5– |Phenyl | |C6H5O– |Phenoxy | Common Names (Alkyl Alkyl Ether Names) • Common names of ethers are formed by naming the two alkyl groups on oxygen and adding the word ether. • Under the current system, the alkyl groups should be named in alphabetical order, but many people still use the old system, which named the groups in order of increasing complexity. • For example, if one of the alkyl groups is methyl and the other is t- butyl, the current common name should be "t-butyl methyl ether,’’ • But most chemists use the older common name, "methyl t-butyl ether" • If both groups are methyl, the name is "dimethyl ether.’’ • If just one alkyl group is described in the name, it implies the ether is symmetrical, as in "ethyl ether." STEP 5: Chemical Structure of Ethers (15 minutes). • Ethers are a class of organic compounds that contain an ether group. • An ether group is an oxygen atom connected to two alkyl or aryl groups. • They follow the general formula R-O-R’. The C-O-C linkage is characterized by bond angles of 104.5 degrees, with the C-O distances being about 140 pm. • The oxygen of the ether is more electronegative than the carbons. • Thus, the alpha hydrogens are more acidic than in regular hydrocarbon chains. [pic] STEP 6: Chemical Properties of Ethers (15 minutes). |Activity: Buzzing (5minutes) | | | |ASK students to pair up and buzz on the following question for 5 | |minutes | | | |What are the chemical properties of Ethers? | | | |ALLOW pairs to respond on the question | | | |WRITE their response on the flip chart/board | | | |CLARIFY and SUMMARIZE by using the content in

NTA Level 5 • Semester 1 • PST05106 Aldehydes of Pharmaceutical Importance Pharmaceutical Organic Chemistry • Source Session/Topic 16 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 16: Aldehydes of Pharmaceutical Importance. Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define aldehydes • List aldehydes and their isomers • Explain nomenclature of aldehydes • Draw chemical structure of aldehydes • List chemical properties of aldehydes • Explain chemical reactions of aldehydes Resources Needed: • Flip charts, marker pens, and masking tape. • Black/white board and chalk/whiteboard markers. SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of Aldehydes | | | |Presentation | | |3 |10 minutes |Presentation |Aldehydes and their Isomers | |4 |15 minutes |Presentation |Nomenclature of Aldehydes | |5 |15 minutes |Presentation |Chemical Structure of Aldehydes | |6 |15 minutes |Buzzing |Chemical Properties of Aldehydes | | | |Presentation | | |7 |35 minutes |Group |Chemical Reactions involving | | | |discussion |Aldehydes | | | |Presentation | | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | SESSION CONTENTS. STEP 1: Presentation of Session Title and Learning Tasks (5 minutes). READ or ASK students to read the learning tasks and clarify ASK students if they have any questions before continuing. STEP 2: Definition of Aldehydes (10 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What are Aldehydes? | | | |ALLOW few students to respond | | | |WRITE their responses on the flip chart/ board | | | |CLARIFY and SUMMARISE by using the content below | Aldehydes are compounds of the general formula RCHO (R may be aliphatic or aromatic group) Examples of aldehydes In aldehydes, the carbonyl group has a hydrogen atom attached to it together with either • a second hydrogen atom Or • More commonly, a hydrocarbon group which might be an alkyl group or one containing a benzene ring. [pic] ALDEHYDE STEP 3: Aldehydes and their Isomers (10 minutes). Aldehydes exhibit the following type of isomerism: • Chain (nuclear) Isomerism. o Aldehydes with 4 or more carbon atoms show chain isomerism. For example: [pic] • Position isomerism. o Aromatic aldehydes and higher ketones give position isomers. For example: [pic] • Functional Isomerism. o The general formula of aldehydes, ketones, unsaturated alcohols oxiranes and oxolanes is CnH2nO o C3H6O has isomers as: [pic] STEP 4: Nomenclature of Aldehydes (15 minutes). I. The longest chain carrying the –CHO group is considered as the parent structure. Aldehydes are named by replacing the ‘-e’ of the corresponding alkane by the ending ‘-al’ [pic] II. When R is aromatic just the word aldehyde is added to the aromatic name III.The common name of simple aldehydes end with ‘aldehyde’ Examples: Formaldehyde (=methanal) Acetaldehyde (=ethanal) Propionoaldehyde (=propanal) Butyraldehyde (=butanal) IV. If the aldehyde group is attached to a large unit (ring), the suffix carbaldehyde is used.[pic] [pic] STEP 5: Chemical Structure of Aldehydes (15 minutes). In an aldehyde, at least one of the attached groups must be a hydrogen atom. The following compounds are aldehydes: [pic] • In condensed formulas, we use CHO to identify an aldehyde rather than COH, which might be confused with an alcohol. • This follows the general rule that in condensed structural formulas H comes after the atom it is attached to (usually C, N, or O). [pic] Some structures of simple aldehydes [pic] STEP 6: Chemical Properties of Aldehydes (15 minutes). |Activity: Buzzing (5minutes) | | | |ASK students to pair up and buzz on the following question for 5 | |minutes. | | | |What are the chemical properties of Aldehydes? | | | |ALLOW pairs to respond on the question. | | | |WRITE their response on the flip chart/board. | | | |CLARIFY and SUMMARIZE by using the content in the table 1 below | • Aldehydes can be reduced to a variety of compounds under different conditions with different reducing agents. • Aldehydes are reduced to the corresponding alcohols by; o Addition of hydrogen in the presence of catalysts like finely divided platinum, palladium, nickel and ruthenium. o Treatment with chemical reagents such as sodium borohydride (NaBH4) or Lithium aluminium hydride (LiAlH4). • Aldehydes are easily oxdised to carboxylic acids on treatment with common oxidising agents like nitric acid, potassium permanganate, potassium dichromate etc. • Aldehydes respond to the Fehlings' test. o Fehlings' solution is an alkaline solution of copper sulphate containing sodium potassium tartrate (Rochelle Salt) as a complexing agent. o Aldehydes on warming with solution, give a red precipitate of cuprous oxide as a result of the redox reaction. o Aromatic aldehydes give very poor results in this test. STEP 7: Chemical Reactions involving Aldehydes (35 Minutes). |Activity: Small Group Discussion (15 minutes) | | | |DIVIDE students into small groups. | | | |ASK students to discuss in groups on the following questions | |What are the chemical reactions involving Aldehydes? | | | |[pic]REFER Students to Book | | | |ALLOW students to discuss for 10 minutes. | | | |ALLOW each group to present for 5 minutes. | | | |CLARIFY and SUMMARIZE by using the contents below | • Aldehydes undergo many reactions to give a wide variety of useful derivatives. • Their most common reaction is nucleophilic addition, addition of a nucleophile and a proton across the C = O double bond. • The reactivity of the carbonyl group arises from the electronegativity of the oxygen atom and the resulting polarization of the carbon-oxygen double bond. • The electrophilic carbonyl carbon atom is sp2 hybridized and flat, leaving it relatively unhindered and open to attack from either face of the double bond.

NTA Level 5 • Semester 1 • PST05106 Ketones of Pharmaceutical Importance Pharmaceutical Organic Chemistry • Source Session/Topic 17 Full source-text version: all educational wording from the extracted learning source is retained; only presenter/tutor metadata and web-layout noise are removed, while formatting is improved for readability. Session 17: Ketones of Pharmaceutical Importance. Total Session Time: 120 minutes Prerequisites • None Learning Tasks By the end of this session students are expected to be able to: • Define ketones • List ketones and their isomers • Explain nomenclature of ketones • Draw chemical structure of ketones • List chemical properties of ketones • Explain chemical reactions of ketones Resources Needed: • Flip charts, marker pens, and masking tape. • Black/white board and chalk/whiteboard markers. SESSION OVERVIEW |Step |Time |Activity/ |Content | | | |Method | | |1 |05 minutes |Presentation |Introduction, Learning Tasks | |2 |10 minutes |Brainstorming |Definition of Ketones | | | |Presentation | | |3 |15 minutes |Presentation |Ketones and their Isomers | |4 |15 minutes |Presentation |Nomenclature of Ketones | |5 |15 minutes |Presentation |Chemical Structure of Ketones | |6 |15 minutes |Buzzing |Chemical Properties of Ketones | | | |Presentation | | |7 |35 minutes |Group |Chemical Reactions involving Ketones| | | |discussion | | | | |Presentation | | |8 |05 minutes |Presentation |Key Points | |9 |05 minutes |Presentation |Evaluation | SESSION CONTENTS. STEP 1: Presentation of Session Title and Learning Tasks (5 minutes) READ or ASK students to read the learning tasks and clarify. ASK students if they have any questions before continuing. STEP 2: Definition of Ketones (10 minutes). |Activity: Brainstorming (5 minutes) | | | |Ask students to brainstorm on the following question: | | | |What is Ketone? | | | |ALLOW few students to respond. | | | |WRITE their responses on the flip chart/ board. | | | |CLARIFY and SUMMARISE by using the content below | • A ketone is a carbonyl compound which has two alkyl (or aryl) groups bonded to the carbonyl carbon atom. [pic] • Aldehydes and Ketones are similar in structure, and they have similar properties • There are some differences, particularly in their reactions with oxidizing agents and with nucleophiles • In most cases Aldehydes are more reactive than Ketones STEP 3: Ketones and their Isomers (10 minutes). Ketones exhibit the following type of isomerism: • Chain (nuclear) Isomerism. o Aldehydes with 4 or more carbon atoms and ketones with five or more carbon atoms show chain isomerism. For example: [pic] • Position lsomerism. o Aromatic aldehydes and higher ketones give position isomers. For example: [pic] • Functional Isomerism. o The general formula of aldehydes, ketones, unsaturated alcohols oxiranes and oxolanes is CnH2nO o C3H6O has isomers as: [pic] STEP 4: Nomenclature of Ketones (15 minutes). • The longest chain carrying the –CHO group is considered as the parent structure. o Ketones are named by replacing the ‘-e’ of the corresponding alkane by the ending ‘-one’ o The alkane name becomes alkanone [pic] • The position of the attached group is indicated with number. The carbonyl carbon= 1 o When R is aromatic just the word ketone is added to the aromatic name • In open-chain ketones, we number the longest chain that includes the carbonyl carbon from the end closest to the carbonyl group, and we indicate the position of the carbonyl group by a number • In cyclic ketones, the carbonyl carbon atom is assigned the number 1 [pic] [pic] 4-hydroxy-4-methyl-2-pentanone 4-hydroxy-4-methylpentan-2-one • The common names of ketones are derived from the two alkyl groups that are attached to the carbonyl carbon & followed by the word ‘ketone’ [pic] • Some ketones have historical common names. o Dimethyl ketone is always called acetone, and alkyl phenyl ketones are usually named as the acyl group followed by the suffix -phenone. [pic] [pic] STEP 5: Chemical Structure of Ketones (15 minutes). • In a ketone, two carbon groups are attached to the carbonyl carbon atom. • The following general formulas, in which R represents an alkyl group and Ar stands for an aryl group, represent ketones. [pic] • In condensed formulas, we use CHO to identify an aldehyde rather than COH, which might be confused with an alcohol. • This follows the general rule that in condensed structural formulas H comes after the atom it is attached to (usually C, N, or O). [pic] Some simple structures of ketones [pic] STEP 6: Chemical Properties of Ketones (15 minutes). |Activity: Buzzing (5minutes). | | | |ASK students to pair up and buzz on the following question for 5 | |minutes. | | | |What are the chemical properties of Ketones? | | | |ALLOW pairs to respond on the question. | | | |WRITE their response on the flip chart/board. | | | |CLARIFY and SUMMARIZE by using the content in the table 1 below | • Ketones undergoes addition reactions in presence of catalyst like finely divided platinum, palladium and nickel. • Ketones having at least one methyl group linked to the carbonyl carbon atom (i.e., methyl ketones) are oxidised by sodium hypohalite to sodium salts of carboxylic acids with one carbon atom less than that of the ketones. • Ketones can be reduced to a variety of compounds under different conditions with different reducing agents. • Ketones are oxidised only under vigorous conditions using powerful oxidising agents such as conc. HNO3, KMnO4/H2SO4, K2Cr2O7/H2SO4 etc. o Oxidation of ketones involves cleavage of bond between carbonyl carbon and a-carbon on either side of keto group giving a mixture of carboxylic acids. STEP 7: Chemical Reactions involving Ketones (35 Minutes) |Activity: Small Group Discussion (15 minutes) | | | |DIVIDE students into small groups | | | |ASK students to discuss in groups on the following questions. | |What are the chemical reactions involving Ketones? | | | |[pic]REFER Students to Book | | | |ALLOW students to discuss for 10 minutes. | | | |ALLOW each group to present for 5 minutes.