Isobutylamine → Piperlonguminine

Participants

Reaction Conditions

Reaction Steps

A mixture of piperinic acid (350 mg, 0.0016 mole, 1 eq) and triethylamine (0.4 ml, 0.0032 mole, 2 eq) in dichloromethane (50 ml) was stirred for 15 min at 0° C. To this mixture methanesulfonyl chloride (0.18 ml, 0.0024 mole, 1.5 eq) was added and stirred for further 30 min at 0° C. Isobutylamine (0.23 ml, 0.0024 mole, 1.5 eq) was added to the mixture and stirred for 1 h at 0° C. and 2 h at room temperature. Dichloromethane (50 ml) was added to the mixture which was then washed with 5% HCl (3×100 ml), saturated aqueous NaHCO3 (3×100 ml) and water (3×100 ml). The organic fraction was dried over anhydrous sodium sulphate, filtered and rotary evaporated to yield a yellowish solid residue. Recrystallisation from methanol yielded colourless needles of piperlonguminine (120 mg, 32% yield)2. The reaction is presumed to proceed through a mesylate ester intermediate. Piperlonguminine (RV-A06)

Provenance & Evidence