Methanol → Cyclopropyl-[4-((S)-2-methyl-piperazin-1-yl)-piperidin-1-yl]-methanone

Participants

Reaction Steps

To a mixture of (S)-3-methyl-piperazine-1-carboxylic acid tert-butyl ester (220 mg, 1.1 mmol) and 1-(cyclopropylcarbonyl)piperidin-4-one (150 mg, 0.9 mmol) in methanol (5 mL, 120 mmol) was added slowly trifluoroacetic acid (6.9 μL, 0.09 mmol) followed by sodium cyanoborohydride (56 mg, 0.9 mmol). The reaction mixture was stirred overnight at RT, concentrated by rotary evaporation, washed with 1 N NaOH (20 mL) and extracted with EtOAc (3×15 mL). Combined organic fractions were washed with brine, dried with sodium sulfate, and concentrated by rotary evaporation to afford a white solid (320 mg). A mixture of the white solid in 4 M HCl in 1,4-dioxane (5 mL) was stirred at RT for 30 min and concentrated to provide the di-HCl salt of the title intermediate (180 mg, 62% yield) as a white suspension.

Provenance & Evidence