Melting Points Amides have very high melting points. Melting points increase with increasing number of N-H bonds. -N CH CH dimethylformamide N-methylacetamide propionamide m.p.-61C m.p.28C m.p.79°C
Melting Points ◼Amides have very high melting points. ◼Melting points increase with increasing number of N-H bonds. m.p. -61C m.p. 28C m.p. 79C
Solubility Acid chlorides and anhydrides are too reactive to be used with water or alcohol. Esters,3 amides,and nitriles are good polar aprotic solvents. Solvents commonly used in organic reactions: ●Ethyl acetate Dimethylformamide (DMF) ●Acetonitrile
Solubility ◼Acid chlorides and anhydrides are too reactive to be used with water or alcohol. ◼Esters, 3 amides, and nitriles are good polar aprotic solvents. ◼Solvents commonly used in organic reactions: ⚫Ethyl acetate ⚫Dimethylformamide (DMF) ⚫Acetonitrile
自标特铁 教华院 Relative reactivity of the carbonyl group towards nuceophilic attack 且>)〉A>）〉& acyl aldehyde ketone anhydride ester amide chloride acid 一I效应：一C> OC-R1>-OR>-NH2 共效应：-<-。R<-R<-
Sec 2 Interconversion of Acid Derivatives Nucleophile adds to the carbonyl to form a tetrahedral intermediate. Leaving group leaves and C=O regenerates. Nuc: R Nuc nucleophilic attack tetrahedral intermediate Y: R Nuc Nuc tetrahedral intermediate products leaving group Copyright 2005 Pearson Prentice Hall,Inc
Sec 2 Interconversion of Acid Derivatives ◼Nucleophile adds to the carbonyl to form a tetrahedral intermediate. ◼Leaving group leaves and C=O regenerates
Reactivity Reactivity decreases as leaving group becomes more basic. Reactivity Derivative Leaving group Basicity more reactive less basic acid chloride R anhydride O-C-R ester OR amide -NH, less reactive carboxylate more basic Copyright@2005 Pearson Prentice Hall.Inc
Reactivity Reactivity decreases as leaving group becomes more basic