Formic Acid → 3-{3-[N-(2-(3,4-Dimethoxyphenyl)-ethyl)-N-methylamino]-propyloxy}-5-(3,4-dimethoxyphenyl)-pyrazole

Participants

Reaction Steps

2 g of 3-{3-[N-(2-(3,4-Dimethoxyphenyl)-ethyl)-N-methylamino]-propyloxy}-5-(3,4-dimethoxyphenyl)-2-benzyl-pyrazole prepared according to Example 13 were dissolved in 10 ml of methanol and added to 2 g of palladium black under nitrogen. 5.5 ml of 98% strength formic acid were added to the solution, which was stirred under nitrogen. After the mixture had been stirred for 3 hours under nitrogen the catalyst was filtered out, and the filtrate was concentrated by evaporation. The oily residue was taken up in saturated sodium carbonate solution and extracted repeatedly with ethyl acetate. The combined organic phases were dried with sodium sulfate and concentrated by evaporation. 1.6 g of 3-{3-[N-(2-(3,4-Dimethoxyphenyl)-ethyl)-N-methylamino]-propyloxy}-5-(3,4-dimethoxyphenyl)-pyrazole were obtained as an oily base. This base was converted analogously to Example 1E) into the hydrochloride having a melting point of 189° to 192° C.

Provenance & Evidence