Salicylamide → 2-(2-Hydroxyphenyl)-4H-1,3-benzoxazin-4-one

Participants

Reaction Conditions

Reaction Steps

U.S. Pat. No. 6,465,504 discloses substituted 3,5-diphenyl-1,2,4-triazoles and their use as pharmaceutical metal chelators. This patent describes a process for the preparation of 4-[3,5-Bis(2-hydroxyphenyl)-1H-1,2,4-triazol-1-yl]benzoic acid (deferasirox) (1) that involves the condensation of salicylamide (2) with salicyloyl chloride (3) by heating at 170° C. yielding 2-(2-hydroxyphenyl)-benz[e][1,3]oxazin-4-one (5), which reacts with 4-hydrazinobenzoic acid (6) in refluxing ethanol to give (1) (Scheme 1):

Provenance & Evidence