Process for preparation of benzphetamine and its pharmaceutically acceptable salts
AssigneeEmcure Pharmaceuticals Limited
InventorsMukund Keshav Gurjar, Narendra Kumar Tripathy, Kiran Avinash Bapat, Vemavarapu P. K. V. Rao, Satyajeet Binay Biswas, Samit Satish Mehta
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Abstract
The present invention provides a simple method for preparation of benzphetamine and its acid addition salt comprising reaction of methamphetamine hydrochloride of formula (III) with benzyl chloride and treating the isolated benzphetamine of formula (II) with an acid dissolved in an organic solvent to provide benzphetamine acid addition salt, more specifically, benzphetamine hydrochloride of formula (I).
Claims14
A process for the preparation of an acid addition salt of benzphetamine comprising
- a) i) reacting methamphetamine hydrochloride of formula (III)
- with benzyl chloride in the presence of a mild base and water at a temperature between 70 and 80° C. to form a reaction mixture, and
- ii) isolating benzphetamine of formula (II) from the reaction mixture
- b) treating the benzphetamine of Formula (II) with an acid in an organic solvent to form a second reaction mixture;
- and
- c) isolating the acid addition salt of benzphetamine from the second reaction mixture.
A process for the preparation of benzphetamine hydrochloride comprising:
- a) reacting methamphetamine hydrochloride of formula (III)
- with benzyl chloride in the presence of potassium carbonate and water at a temperature of 75±2° C.;
- b) i) adding toluene and
- ii) isolating benzphetamine of formula (II) by concentrating the organic layer,
- c) i) treating the benzphetamine of formula (II) with anhydrous hydrochloric acid in ethyl acetate under anhydrous conditions to form a reaction mixture,
- ii) concentrating the reaction mixture, and
- iii) adding an ester solvent;
- and
- d) isolating benzphetamine hydrochloride salt of formula (I)
A process for the preparation of benzphetamine of formula (II)
- comprising reacting methamphetamine hydrochloride of formula (III)
- with benzyl chloride in the presence of a mild base and water at a temperature between 70 and 80° C.
Dependencies are inferred from the claim text.