AN IMPROVED PROCESS FOR THE PREPARATION OF TERBINAFINE HYDROCHLORIDE

摘要

The present invention relates to an improved process for preparation of terbinafine hydrochloride ,which is (E) - N- Methyl -N-(1-Naphtylmethyl)-6,6-dimethylhept-2-ene-4-ynyl-1-amine has the formula (I), which comprises reacting t-butylacetylene with ethylmagnesium bromide in THF (ii) adding acrolein at a temperature in the range of 0-10o C to get , 6,6-dimethyl-hept-1-ene-4-yne-3-ol, (iii) reacting it with a mixture of phosphorous oxychloride and hydrochloric acid in methanol (iv) extracting the reaction mass with aliphatic/aromatic solvent & removing the solvent (v) reacting the residue with N-(1-naphtylmethyl)methyl amine in the presence of a base to give Terbinafine (vi) adding hydrochloric acid and extracting the Terbinafine Hcl formed with a chlorinated solvent and (vii) recovering the chlorinated solvent under vacuum and adding ethylacetate to separate Terninafine hydrochloride which is filtered and dried.