1-Piperazinecarbonyl chloride, 4-(methylsulfonyl)- synthesis

Yield:65463-96-9 79%

Reaction Conditions:

with pyridine in dichloromethane at 0 - 20;

Steps:

15

4-Methanesulfonyl-piperazine-1-carbonyl chloride To a stirred solution of carbonic acid ditrichloromethyl ester (triphosgene) (1.81 g, 6.09 mmol) in CH₂Cl₂ (30 ml) at 0° C., was added a solution of 1-methanesulfonyl-piperazine (2.0 g, 12.2 mmol) and pyridine (1.08 ml, 13.4 mmol) in CH₂Cl₂ (5 ml) over 30 minutes. The temperature was raised to RT, and stirring was continued over night. The organic phase was washed with H₂O, dried over Na₂SO₄. Purification by flash chromatography (SiO₂, EtOAc) yielded 2.20 g (79%) of the title compound as white solid.

References:

US2008/275021,2008,A1 Location in patent:Page/Page column 19