Water → HCID 30772162, compound

Participants

Reaction Conditions

Reaction Steps

Triethylamine (4.2 ml) was added to a stirred solution of 2,4-dichloronitrobenzene (1.9 g) and 1-t-butoxycarbonyl-piperazine (2.2 g) in dimethylsulfoxide (18 ml) under N2. The resulting solution was stirred at 70° C. for 48 hours then cooled to room temperature. Water was added and the mixture extracted three times with ethyl acetate; the combined organic layers were dried over sodium sulfate and concentrated in vacuo. The residue was subjected to silica gel chromatography (cyclohexane:ethyl acetate 8:2) to afford 4-(5-chloro-2-nitrophenyl)-piperazine-1-carboxylic acid tert-butyl ester (2.6 g) as a foam. 1H NMR (400 MHz, CDCl3) 1.5 (s, 9H), 2.9 (br s, 4H), 3.5 (br s, 4H), 6.9 (d, J=10 Hz, 1H), 7.0 (s, 1H), 7.7 (d, J=10 Hz, 1H); MS (ES+) 242/244 (M+H+—CO2-isobutene), 286/288 (M+H+-isobutene).

Provenance & Evidence