Method for synthesizing doxepin hydrochloride

• Main Author: YANG YINGJIN
• Format: Patent
• Language: Chinese; English
• Published: 13.02.2013
• Subjects: CHEMISTRY; CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION ORPROCESSING OF GOODS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE

The invention provides a method for synthesizing doxepin hydrochloride. The method comprises the following steps of: 1, carrying out an addition reaction on 6,11-dihydrobenz [b,e] oxepin-11-one and 3-chloropropyl-methyl tert-butyl ether to obtain alcohol compounds; 2, removing hydroxyl from the alcohol compounds under the condition of concentrated hydrochloric acid to obtain olefin compounds; 3, reacting the olefin compounds with thionyl chloride in a reaction solvent to obtain chloride; 4, coupling the chloride with N,N-dimethyl methylamine to obtain doxepin; and 5, preparing the doxepin into hydrochloride of the doxepin to obtain the doxepin hydrochloride. An Ni(OAc)2/PPh3 system is creatively used in C-N coupling reaction in the step 4, thus the doxepin hydrochloride has the characteristics of good reaction selectivity, high yield and environmental friendliness; and the catalyst is can be recycled after being simply filtered, thus the production cost is greatly lowered. The whole method has the advantages