Studies on Syntheses of Thiohydantoin Related Compounds. XVII. Synthesis of 1, 3-Diphenyl-5-butylhydantoin

Abstract

1, 3-Diphenyl-5-butylhydantoin (I) was synthesized by two methods, indirect and direct, with the object of the development of a new analgesic agent. In the course of the indirect method, treatment of 1, 3-diphenyl-2-thiohydantoin (IV) with n-butylaldehyde gave 1, 3-diphenyl-5-butylidene-2-thiohydantoin (V) as two kinds of crystals, which were confirmed to be geometrical isomers with each other. The configurations of them were determined from the NMR spectral data. Two by-products obtained in this reaction was also geometrical isomers with each other, and they were deduced to be dimers of 1, 3-diphenyl-5-butylidene-2-thiohydantoin, 1, 3-diphenyl-5-{β-ethyl-γ-(1, 3-diphenyl-2-thiohydantoinyl)} hexylidene-2-thiohydantoin (Xa and Xb) from some physical data. In the direct method, 1, 3-diphenyl-5-butylhydantoin was obtained in 40% yield by refluxing 2-anilinohexanoic acid (IX) and phenyl isocyanate in xylene.