An efficient synthesis of 2-(2,2-difluoroethoxy)-6-trifluoromethyl-n(5,8-dimethoxy-1,2,4-triazolo[1,5-c]pyrimidine-2-yl) benzenesulfonamide: penoxsulam.

Wu, Feifei; Gao, Shiguang; Chen, Zhiyin; Su, Jinyue; Zhang, Dayong

An efficient nine-step synthesis of 2-(2,2-difluoroethoxy)-6-trifluoromethyl-N-(5,8-dimethoxy-1,2,4-triazolo[1,5-c]-pyrimidine-2-yl) benzenesulfonamide has been developed. The starting material 4-nitro-2-(trifluoromethyl)aniline starting material was converted via 2-bromo-4-amino-6-trifluoromethylaniline and 2-bromo-4-acetamido-6-trifluoromethylbenzenesulfonic acid to 2-bromo-6-trilfuoromethylbenzenesulfonic acid. This was then combined with 2-amino-5,8-dimethoxy-1,2,4-triazolo[1.5-c]pyrimidine to give the target molecule. Compared with the reported method, this approach has advantages in its shorter reaction time, milder reaction conditions and easier purifiction. Moreover, the overall yield has been improved to 22.9% which is twice of that of the reported method.

TRIFLUOROMETHYL compounds; PYRIMIDINES; BENZENESULFONAMIDES; PENOXSULAM; REACTION time

Journal of Chemical Research, 2013, Vol 37, Issue 4, p197

1747-5198

Academic Journal

10.3184/174751913X13619014318618