反应详情

To a solution of piperazine-1-carboxylic acid tert-butyl ester (521 mg, 2.8 mmol) in DCM (6 ml) was added NEt3 (547 μl, 3.92 mmol, 1.4 eq.) and 4-trifluoromethoxy-benzenesulfonyl chloride (880 mg, 3.36 mmol, 1.2 eq.). The reaction mixture was stirred at room temperature for 12 hrs. The excess of sulfonyl chloride was quenched by addition of trisamine resin (150 mg), and subsequent stirring for 2 hrs. The resin was then filtered off, and NaHCO3 sat (5 ml) was added. Filtration of the resulting mixture through hydrophobic catridge and subsequent removal of the solvent under reduced pressure afforded the desired 4-(4-trifluoromethoxy-benzenesulfonyl)-piperazine-1-carboxylic acid tert-butyl ester in quantitative yield.

1. customThe excess of sulfonyl chloride was quenched by addition of trisamine resin (150 mg)
2. stirringsubsequent stirring for 2 hrs
3. filtrationThe resin was then filtered off
4. additionwas added
5. filtrationFiltration of the resulting mixture
6. customthrough hydrophobic catridge and subsequent removal of the solvent under reduced pressure