9+9+9Synthesis of N,N min-bis(4-methyloxazl-5-yl)-urea as the key building block of 1,3-bis(4-methyloxazol-5-yl)xanthine towards an improved bronchodilator

摘要

4-Methyloxazole-5-carboxylic acid 2 is converted to 4-methyloxazol-5-yl carboxazide 3 is a one-pot reaction wiht ethyl chloroformate and triethylamine in cold followed by treatment with sodium azide.