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

Participants

Reaction Steps

U.S. Pat. No. 6,465,504 discloses a process for preparing Deferasirox wherein the process includes reacting salicyloyl chloride with salicylamide at 170° C. to obtain 2-(2-hydroxyphenyl)benz[e][1,3]oxazin-4-one, and further crystallization in ethanol to obtain slight yellow color crystals of 2-(2-hydroxyphenyl)benz[e][1,3]oxazin-4-one. 2-(2-hydroxyphenyl)benz[e][1,3]oxazin-4-one which is further reacted with 4-hydrazinebenzoic acid in presence of ethanol to give Deferasirox. Major drawback of this process is preparation of 2-(2-hydroxyphenyl)benz[e][1,3]oxazin-4-one at high temperature and in the absence of solvent which causes formation of several impurities which is difficult to avoid.

Provenance & Evidence