Sodium Hydroxide → 1-[2-[4-(6-Trifluoromethyl-benzo[b]thiophen-3-yl)-piperazin-1-yl]-ethyl]-cyclopropanecarboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 4.2 g (14.7 mmol) of 1-(6-trifluoromethyl-benzo[b]thiophen-3-yl)-piperazine in 100 mL of dichloromethane under nitrogen was added 3.5 g (19.1 mmol) of 1-(2-Oxo-ethyl)-cyclopropanecarboxylic acid tert-butyl ester. After stirring 10 minutes at room temperature 6.5 g (30.7 mmol) of sodium triacetoxyborohydride was added portion-wise. After 30 minutes 100 mL of 0.5 N aqueous sodium hydroxide was added and the reaction was stirred for 15 minutes. The organic layer was separated, dried and concentrated to deliver a paste. This was taken up in methanolic hydrogen chloride. The salt thus obtained was recrystallized from ethyl acetate/methanol to deliver 6.6 g (13.4 mmol) of the desired product as a white powder mp=187-9° C.

Provenance & Evidence