Diisopropylethylamine → 4-(4-Nitro-2-trifluoromethyl-benzenesulfonyl)-piperazine-1-carboxylic acid benzyl ester

Participants

Reaction Steps

Diisopropylethylamine (1.2 ml, 7.0 mmol) was added in one portion to a stirred solution of piperazine-1-carboxylic acid benzyl ester (0.76 g, 3.5 mmol) in DCM (15 ml) at room temperature. To this mixture was added 4-nitro-2-trifluoromethyl-benzenesulfonyl chloride (1.0 g, 3.5 mmol) in one portion and the mixture was stirred at room temperature under a nitrogen atmosphere for 1 hour. After this time, the mixture was diluted with DCM (20 ml), washed with HCl (1M, 20 ml) and NaOH (1M, 20 ml). The organic layer was separated, dried (MgSO4), filtered and concentrated under vacuum to give the title compound (1.43 g, 87% yield) as a purple solid. δH (500 MHz, DMSO) 8.65-8.60 (2H, m), 8.31 (1H, d), 7.38-7.29 (5H, m), 5.07 (2H, s), 3.56-3.46 (4H, m), 3.30-3.25 (4H, m). Tr=2.25 min m/z (ES+) (M+Na+) 496.

Provenance & Evidence