Synthesis of 1H-imidazoles by the simple ring transformation of 5-acylaminouracils and 5-acylaminopyrimidin-4(3H)-ones

Abstract

1,2-Disubstituted 4-alkylcarbamoyl-5-methyl-1H-imidazoles and 2-substituted 5-methyl-4-phenylcarbamoyl-1H-imidazoles were synthesized from 5-acylamino-6-methyluracils and 5-acylamino-6-methyl-3-phenylpyrimidin-4(3H)ones by treatment with sodium hydroxide in ethanol. In the case of 5-acylaminopyrimidinones which possess an olefinic group in the acylamino group, 2-ethoxyethyl (or 2-ethoxypropyl)-5-methyl-4-phenylcarbamoyl-1H-imidazoles were prepared as major products and the corresponding 2-alkenyl-1H-imidazoles were only minor products. Compounds which contain an aryl function in their acylamino group gave glycine anilides as by products.