Biological Deacetylation of Acetamido Compounds and Formation of Benzoxazolone

Abstract

IN a recent paper, Smith and Williams¹ discuss the fact observed by Jaffé and Hilbert² that acetanilide is hydroxylated by the dog mainly in the ortho position and by the rabbit only in the para position. They postulate that this difference may be due to the different degrees of deacetylation which take place in the two animals. The dog is known to be much less efficient than the rabbit in acetylating the aromatic amino group^3,4, although it is able to acetylate aliphatic amino groups, as in the formation of mercapturic acids⁵. The deacetylation of acetanilide in the dog does not appear to have been reported upon but we have observed, in agreement with Smith and Williams, that the rabbit deacetylates it to only a slight extent (not more than 2–3 per cent). The deacetylation of acetylsulphamezathine by the dog and rabbit has been studied by Krebs, Sykes and Bartley⁶, who found that the former deacetylates about 29 per cent of an injected dose whereas the latter deacetylates only 1 per cent in the same time. It would therefore be expected that considerable deacetylation of acetanilide would occur in the dog.