The invention provides a process for the preparation of a compound of the formula 6 comprising the hydrolysis and decarboxylation of a compound of the formula 5 according to the reaction:
1
wherein R and R
2
independently a C
1
-C
4
alkyl group or an aralkyl group.
[EN] PREPARATION OF INTERMEDIATES FOR ACETYL CHOLINESTERASE INHIBITORS<br/>[FR] PREPARATION D'INTERMEDIAIRES POUR INHIBITEURS DE L'ACETYL CHOLINESTERASE
申请人:HETERO DRUGS LTD
公开号:WO2005003092A1
公开(公告)日:2005-01-13
A simple, industrial process for the preparation of the intermediates of acetyl cholinesterase inhibitors is provided. Thus, for example, 5,6-dimethoxy-2-(4-pyridyl)methyl-1-indanone is hydrogenated using platinum oxide catalyst in the presence of hydrochloric acid under a pressure of 2 bars to give 4-[(5,6-dimethoxy-1-indanon)-2-yl] methylpiperidine hydrochloride, which is then converted to donepezil hydrochloride, an acetyl cholinesterase inhibitor.
Novel Process for Production of Highly Pure Polymorph (I) Donepezil Hydrochloride
申请人:Neu Jozsef
公开号:US20080306271A1
公开(公告)日:2008-12-11
The present invention provides a novel, industrially realizable and economically preferable process for production of highly pure 1-benzyl-4-[(5,6-dimethoxy-1-indanon)-2-yl]methyl piperidine hydrochloride, i.e., donepezil hydrochloride shown in the following reaction scheme, in Polymorph (I) morphological crystal form. (I) In one of the key steps of the process, during the hydrogenation 5,6-dimethoxy 2-(pyridine-4-yhnethylene)indan-
1
-one hydrochloride is saturated using Pd carbon to get 4-[(5,6-dimethoxy-
1
-indanon)-2-yl]-methyl piperidine at more than 97% HPLC purity. In the crystallization step donepezil-hydrochloride is crystallized from an aqueous alcoholic solvent to get Polymorph (I) in at least 99.95% HPLC purity.
Preparation of intermediates for acetyl cholinesterase inhibitors
申请人:Parthasardhi Bandi Reddy
公开号:US20060041140A1
公开(公告)日:2006-02-23
A simple, industrial process for the preparation of the intermediates of acetyl cholinesterase inhibitors is provided. Thus, for example, 5,6-dimethoxy-2-(4-pyridyl)methyl-1-indanone is hydrogenated using platinum oxide catalyst in the presence of hydrochloric acid under a pressure of 2 bars to give 4-[(5,6-dimethoxy-1-indanon)-2-yl]methylpiperidine hydrochloride, which is then converted to donepezil hydrochloride, an acetyl cholinesterase inhibitor.