Heterocyclic compounds from alloxan and amines. XI. Uramils, dialuric acids, and related compounds

Abstract

Preparation of a number of uramils and 5-aryldialuric acids from o-substituted anilines is described. Methylation of the uramils gave dimethoxy-N-monomethyl pyrimidine derivatives accompanied by minor amounts of trimethoxy-pyrimidines, and the dialuric acids gave 1,3-dimethylpyrimidines or 5-methoxy-1,3-dimethylbarbituric acids (with an excess of diazomethane). Ring contraction of the 1,3-dimethyldialuric acids gave the isomeric 5-N-methylcarbamoyloxazolidine-2,4-diones. The dialuric acid from dimedone gave a trimethyl derivative (a methoxycyclohexenyl-1,3-dimethyldialuric acid). Anthranilic acid and alloxan in acetic acid gave a benzoxazonespirobarbituric acid, but in aqueous ethanol yielded a dialuric acid which was characterized by conversion into several derivatives. Infrared and N.M.R. data are recorded for the uramils, dialuric acids, and their derivatives.