Diisopropyl Ether → (R)-4-(4-trifluoromethoxy-benzenesulfonyl)-3-(4-trifluoromethoxy-benzylcarbamoyl)-piperazine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of the compound (2.40 g) obtained in Step 2, 4-trifluoromethoxybenzylamine (1.21 g) and 1-hydroxybenzotriazole hydrate (1.21 g) in N,N-dimethylformamide (24 ml) was added, with stirring under ice-cooling, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (1.21 g). After stirring overnight at room temperature, and the reaction mixture was partitioned by adding ethyl acetate and water. The organic layer was washed successively with saturated aqueous sodium hydrogen carbonate solution, 10% aqueous citric acid solution and saturated brine, dried over anhydrous magnesium sulfate, filtrated, and concentrated under reduced pressure. The obtained crude crystals were suspended in a mixed solution of diisopropyl ether and n-hexane, collected by filtration and dried to give the title compound (2.20 g).

Provenance & Evidence