6-Fluoro-1-(propan-2-yl)-3,4-dihydronaphthalen-2(1H)-one → N-[3-(1H-benzimidazol-2-yl)propyl]-2-(6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl)-N-methylacetamide

Participants

Reaction Steps

A method of preparing 2-[2-{[3-(1H-benzimidazol-2-yl)propyl]methylamino)}ethyl]-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl methoxyacetate comprises contacting 6-fluoro-1-isopropyl-3,4-dihydro-1H-naphthalen-2-one with the dianion of N-[3-(1H-benzimidazol-2-yl)propyl]-N-methylacetamide to form N-[3-(1H-benzimidazol-2-yl)propyl]-2-(6-fluoro-2-hydroxy-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl)-N-methylacetamide, reducing this to 2-[2-{[3-(1H-benzimidazol-2-yl)propyl]methylamino}ethyl]-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ol, and treating the 2-[2-{[3-(1H-benzimidazol-2-yl)propyl]methylamino}ethyl]-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ol with methoxyacetic acid or an activated derivative of methoxyacetic acid. The invention is particularly applicable to the preparation of mibefradil, (lS,2S)-2-[2-{[3-(1H-benzimidazol-2-yl)propyl]methylamino}ethyl]-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-yl methoxyacetate, and its dihydrochloride salt. N-[3-(1H-Benzimidazol-2-yl)propyl]-N-methylacetamide, and the acetic acid solvate of 2-[2- {[3-(1H-benzimidazol-2-yl)propyl]methylamino}ethyl]-6-fluoro-1-isopropyl-1,2,3,4-tetrahydronaphthalen-2-ol dioxalate, are new.

Provenance & Evidence