Olanzapine EP Impurity C

Olanzapine EP Impurity C is a chlorinated piperidine derivative featuring a dibenzazepine core fused to a thiazole ring, with two chlorine substituents at positions 10 and 11. This impurity arises as a synthetic byproduct during the coupling of 10-chloro-5H-dibenzo[b,e][1,4]diazepine-5-thione with 4-methylpiperidine, introducing an additional chloro group compared to the parent drug. Its structure retains the tricyclic scaffold of olanzapine but exhibits altered electronic properties due to dual chlorination. This compound serves as a pharmacopeial reference standard for HPLC-based quantification of process-related impurities in olanzapine formulations.