反应详情

U.S. Pat. No. 5,473,078 (“the '078 patent”) describes a method of preparing 4-[1-(1,2,4-triazolyl)methyl]benzonitrile by refluxing a solution of α-bromo-4-tolunitrile with 1,2,4-triazole for 15 hours in a mixture of acetonitrile and chloroform. The intermediate is purified by chromatography on silica gel, eluting with chloroform and isopropanol, and then reacted with 4-fluorobenzonitrile and potassium tert-butoxide in DMF, to obtain letrozole. An exemplary process described in the '078 patent is generally depicted in Scheme 1.

1. customThe intermediate is purified by chromatography on silica gel
2. washeluting with chloroform and isopropanol
3. customreacted with 4-fluorobenzonitrile and potassium tert-butoxide in DMF