Patent ID: 8546573

Claim:
A process for preparing 7-ethyl-10-[4-(1-piperidino)-1-pipericlino]carbonyloxy-camptothecin hydrochloride trihydrate comprising the steps of: i) reacting 4-piperidinopiperidine with triphosgene in presence of dichloromethane and suitable base to obtain [1,4′]bipiperidinyl-1′-carbonyl chloride of formula (II), ii) reacting [1, 4′]bipiperidinyl-1′-carbonyl chloride (II) with 7-ethyl-10-hydroxy camptothecin (III) in the presence of (a) suitable amide, (b) pyridine and (c) a base other than pyridine in a suitable solvent to obtain compound of formula (I), and iii) converting 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy-camptothecin into hydrochloride trihydrate (CPT-11) by reacting with hydrochloric acid in suitable solvent, wherein the suitable solvent is selected from water, alcohol(s), or a mixture of thereof