PhOCH,C CH CH COOH Amides acylated. inactive enzyme Product of the reaction of a carboxylic acid and ammonia or an amine. Not basic because the lone pair on nitrogen is delocalized by resonance. :O: :0: H H H H Bond angles around N are close to120°. => Chapter 21 6
Chapter 21 6 Amides • Product of the reaction of a carboxylic acid and ammonia or an amine. • Not basic because the lone pair on nitrogen is delocalized by resonance. H C O N H H H C O N H H _ + Bond angles around N are close to 120. =>
PhOCH.C COOH Classes of Amides inactive enzyme ·1°amide has one C-N bond(woN-H). ·2°amide or N-substituted amide has two C-N bonds (one N-H) ·3°amide or M,W-disubstituted amide has three C-N bonds(no N-H) Chapter 21
Chapter 21 7 Classes of Amides • 1 amide has one C-N bond (two N-H). • 2 amide or N-substituted amide has two C-N bonds (one N-H). • 3 amide or N,N-disubstituted amide has three C-N bonds (no N-H). =>
PhOCH,C CH CH COOH Naming Amides acylated enzyme ·For1°amide,drop-icor-oic acid from the carboxylic acid name,add -amide. ·For2°and3°amides,the alkyl groups bonded to nitrogen are named with N- to indicate their position. N-ethyl-N,2-dimethylpropanamide CH:CHC-N-CH2CH3 N-ethyl-N-methylisobutyramide CH3 Chapter 21 8>
Chapter 21 8 Naming Amides • For 1 amide, drop -ic or -oic acid from the carboxylic acid name, add -amide. • For 2 and 3 amides, the alkyl groups bonded to nitrogen are named with Nto indicate their position. CH3 CHC N O CH2 CH3 CH3 CH3 N-ethyl-N,2-dimethylpropanamide N-ethyl-N-methylisobutyramide =>
PhOCH,C- Cyclic Amides COOH acylated. inactive enzyme Reaction of-NH2 and-COOH on same molecule produces a cyclic amide,lactam. To name,add word lactam to the IUPAC acid name or replace the -ic acid of common name with -olactam. 4-aminopentanoic acid lactam N-H y-valerolactam CH; => Chapter 21 9
Chapter 21 9 Cyclic Amides • Reaction of -NH2 and -COOH on same molecule produces a cyclic amide, lactam. • To name, add word lactam to the IUPAC acid name or replace the -ic acid of common name with -olactam. N O CH3 H 4-aminopentanoic acid lactam -valerolactam =>
0 PhOCH,C- NH CH Nitriles CH3 COOH acylated. mnactive .-C=N can be hydrolyzed to carboxylic enzyme acid,so nitriles are acid derivatives. Nitrogen is sp hybridized,lone pair tightly held,so not very basic(pKp about 24) 3> acetonitrile propyne Chapter 21 10
Chapter 21 10 Nitriles • -CN can be hydrolyzed to carboxylic acid, so nitriles are acid derivatives. • Nitrogen is sp hybridized, lone pair tightly held, so not very basic (pKb about 24). =>