Patent ID: 9593086
Date: 2017-03-14
CPC Classifications: C07D

Claim:
1. A process for preparing crystalline form of deferasirox having purity of at least 99%, said process comprising acts of: a. reacting salicyloyl chloride of formula 2 with salicylamide of formula 3 in presence of a catalyst to obtain 2-(2-Hydroxyphenyl)benz[e]oxazin-4-one of formula 4 having less than 1% of uncyclized impurity; b. reacting salicyloyl chloride of formula 2 with salicylamide of formula 3 in presence of a catalyst and a metal base to obtain metal salt of 2-(2-Hydroxyphenyl)benz[e]oxazin-4-one of formula 4 having less than 1% of uncyclized impurity; c. reacting the 2-(2-Hydroxyphenyl)benz[e]oxazin-4-one of step (a), or the metal salt of 2-(2-Hydroxyphenyl)benz[e]oxazin-4-one of step (b), with 4-hydrozenobenzoic acid of formula 5 to obtain semi-pure form of deferasirox; and d. purifying the semi-pure form of deferasirox in a solvent to obtain the crystalline form of deferasirox having purity of at least 99%.