Acetic Acid → (R)-4-(5-tert-butoxycarbonyl-4-methyl-thiazol-2-yl)-1-(4-trifluoromethoxy-benzenesulfonyl)-piperazine-2-carboxylic acid

Participants

Reaction Steps

A mixture of the compound (1.82 g) obtained in Step 5, 10% palladium carbon (250 mg) and acetic acid (4.0 ml) in methanol (50 ml) was stirred under a hydrogen atmosphere (4 atm) at room temperature for 3 hr. The reaction mixture was filtered through celite, and concentrated under reduced pressure. 10% Palladium carbon (1.8 g), acetic acid (4.0 ml) and methanol (50 ml) were added again to the residue, and the mixture was stirred under a hydrogen atmosphere (4 atm) at room temperature for 30 min. The reaction mixture was filtered through celite, and the filtrate was concentrated under reduced pressure. Toluene was added to the residue, and the mixture was concentrated under reduced pressure (repeated 4 times). The obtained powder was suspended in water, collected by filtration and dried to give the title compound (1.24 g).

Provenance & Evidence