Aluminum amides reactions with esters

As in its reactions with esters and amides, bis(2-methylpropyl)aluminum (diisobutylalumi-num) hydride (DIBAL) adds to a nitrile only once to give an imine derivative. Aqueous hydrolysis then produces an aldehyde. 

This procedure, which is based on the work of Ishii and co-workers, affords a mild and general method for converting a wide variety of esters to primary, secondary, and tertiary amides (Table 1). While the preparation of the tertiary amide, N,N-dimethylcyclohexanecarboxamide, described here is carried out in benzene, aluminum amides derived from ammonia and a variety of primary amines have been prepared by reaction with trimethylaluminum in dichloromethane and utilized for aminolysis in this solvent. Although 1 equivalent of the dimethylaluminum amides from amines was generally sufficient for high conversion within 5-48 hours, best results were obtained when 2 equivalents of the aluminum reagent from ammonia was used. Diethyl-aluminum amides can also effect aminolysis, but with considerably slower rates. 

A carboxylic acid group may be introduced into the 2-position of dibenzofuran by Friedel-Crafts reaction with 2,2-dichloro-l,3-benzodioxole (catechol dichloromethylene ether) and hydrolysis of the resultant ester. Similarly, reaction with methylphenylcarbamoyl chloride produces the 2-(N-methyl-yV-phenylcarboxamide) or the 2,8-disubstituted derivative under more stringent conditions. Controlled reduction of these amides with lithium aluminum hydride supplies the corresponding aldehydes. ... 

Reactions of Esters Esters are much more stable than acid chlorides and anhydrides. For example, most esters do not react with water under neutral conditions. They hydrolyze under acidic or basic conditions, however, and an amine can displace the alkoxyl group to form an amide. Lithium aluminum hydride reduces esters to primary alcohols, and Grignard and organolithium reagents add twice to give alcohols (after hydrolysis). 

Section 19.8 Esters give amides on reaction with ammonia and amines and are cleaved to a carboxylic acid and an alcohol on hydrolysis (Table 19.4). Esters react with Grignard reagents and are reduced by lithium aluminum hydride (Table 19.5). 

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