Carboxamides alcoholysis

H-Chromene, 2-ethyl-3-phenyl-synthesis, 3, 764 4H-Chromene, 2-phenyl-synthesis, 3, 763 4H-Chromene, 2,4,4-trimethyl-addition reactions, 3, 669 2 H-Chromene-3-carboxamide reduction, 3, 675 2H-Chromene-3-carboxylic acid methyl ester alcoholysis, 3, 668... 

Alcoholysis of the cis and trans isomers of the dihydrooxazinone 416 was performed with ethanol, n-butanol, 3-phenylbutanol, and menthol, resulting in the corresponding A-benzoylamino esters 417 in excellent yields [77H(7)301]. The aminolysis of 416 with ammonia, aniline, benzylamine, or dibutylamine gave the carboxamides 418 in 52-99% yields [77H(7)301],... 

A few 6- and 8-cyanopurines have been prepared and undergo characteristic nitrile addition reactions rather readily. Thus, alkaline hydrolysis produces carboxamides, then carboxylic acids, alcoholysis leads to imidates, ammonolysis to amidines, hydrazinolysis to amidhydrazines, hydroxylamine to amidoximes, and hydrogen sulfide to thioamides. Acid hydrolysis tends to give the decarboxylated acid derivative. Reduction either by sodium-ethanol or, preferably, by catalytic hydrogenation affords aminoalkylpurines and addition of Grignard reagents produces, in the first place, acylpurines. As with aldehydes, most of the compounds examined have been relatively non-polar derivatives. Table 28 lists some reactions and relevant literature. 

Carboxamides and sometimes carboxylic esters and carbonitriles are formed as by-products of the alcoholysis. 

Two procedures for the preparation of a-oxocarboxylic acids via nitrile intermediates have been described. The autoxidation of 3,3-disubstituted 2-cyanocarboxylate ester anions is reported to provide the related a-oxoesters in fair yield a new general procedure for the conversion of aldehydes into the homologous a-oxoacids is based on theoxidationof a-hydroxy-iV-t-butyl-carboxamides (116), prepared by the acid-catalysed alcoholysis of aldehyde cyanohydrins with t-butanol, to the hitherto ui nown -oxocarboxamides, which are in turn readily converted into the parent a-oxoacids on acid-catalysed hydrolysis. 

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