Acetic Acid → 4-Benzyloxycarbonyl-1-[1-(4-pyridyl)-4-piperidinylamino]-2-piperazinone

Participants

Reaction Conditions

Reaction Steps

A solution of 1-amino-4-benzyloxycarbonyl-2-piperazinone (21.92 g) and 1-(4-pyridyl)-4-piperidone (15.51 g) in ethanol (500 ml) was dehydrated using a Soxlet extractor packed with molecular sieves 4A while refluxing for 24 hours. The reaction mixture was concentrated to obtain a residue, which was dissolved in methanol (300 ml) and combined with acetic acid (18.26 g) with cooling on ice followed by sodium cycanoborohydride (7.16 g) and then stirred at 0° C. for 3 hours. The reaction mixture was concentrated, and the residue was combined with a 1N aqueous solution of sodium hydroxide, and extracted with methylene chloride. The extract was washed with water and brine, dried and concentrated to obtain 4-benzyloxycarbonyl-1-[1-(4-pyridyl)-4-piperidinylamino]-2-piperazinone (25.29 g) as a pale yellow amorphous material.

Provenance & Evidence