HCID 86588492, compound → HCID 12991326, compound

Participants

Reaction Steps

A mixture of N-[(R)-1-[3-(1-tert-butoxycarbonyl-4-piperidyl)propionyl]-3-piperidylcarbonyl]-2(S)-benzyloxy-carbonylamino-β-alanine methyl ester (20 g) and 10% Pd on carbon (50% wet) (5 g) in methanol (500 ml) was stirred vigorously under a hydrogen atmosphere (1 atm) at room temperature. After 2 hours, the insolved material was removed by filtration, and the filtrate was concentrated in vacuo. The residue was dissolved in tetrahydrofuran (200 ml), and cooled to 0° C. 1N aqueous LiOH (116 ml) solution was added to the solution within 15 minutes at 0-3° C. After the mixture was stirred for 45 minutes at 0° C., acetic anhydride (6.89 ml) was added to the mixture within 15 minutes at 0-4° C. The mixture was stirred for 30 minutes at 0° C., then diethyl ether (150 ml) was added. The aqueous layer was separated, and the pH of it was adjusted to 2.5 with aqueous 20% KHSO4 , then extracted with ethyl acetate. The extract was dried over Na2SO4, and concentrated in vacuo to give N-[(R)-1-[3-(1-tert-butoxycarbonyl-4-piperidyl)propionyl]-3-piperidylcarbonyl]-2(S)-acetylamino-β-alanine (16.3 g) as a colorless oil.

Provenance & Evidence