Investigations on arylhydrazones of substituted glyoxylic acids

The reaction of arylhydrazones of ethyl cyanoglyoxylate with hydroxylamine hydrochloride in aqueous ethanolic solution in the presence of sodium acetate at the boil has given 3-amino-4-arylazoisoxazol-5-ones. The reaction of arylhydrazones of ethy cyanoglyoxylate with hydroxylamine in the presence of sodium ethoxide in the cold has given arylhydrazones of the amide-oxime of ethyl mesoxalate. The action of acetic anhydride or aryl isothiocyanates on arylhydrazones of the amide oxime of ethyl mesoxalate has given arylhydrazones of the ethyl esters of 5-substituted 1,2,4-oxadiazolyl- or 1,2, 4-thiadiazolylglyoxylic acids.For part XI, see [11].