Pyridine → 1-(Methylsulfonyl)piperazine

Temperature

0 °C

Benzyl 1-piperazinecarboxylate (2.03 g, 9.22 mmol) was dissolved in pyridine (23.0 mL, 9.22 mmol) and cooled to 0° C. before methanesulfonyl chloride (2.85 mL, 36.9 mmol) was added. The reaction mixture was stirred at 0° C. for 30 minutes and warmed to RT for 2 h. The reaction mixture was diluted with 75 mL of ethyl acetate, added to a separation funnel, partitioned with 3 N HCl (aqueous), washed 3× with 50 mL of 3 N HCl (aqueous), and separated, before the aqueous layer was extracted 3× with chloroform/isopropanol, then dried over sodium sulfate, and concentrated in vacuo to give the title compound. Benzyl 4-(methylsulfonyl)piperazine-1-carboxylate (2.80 g, 9.4 mmol) was dissolved in ethanol (0.43 g, 9.4 mmol) before palladium, 10 wt. % on activated carbon (2.0 g) was added and a hydrogen balloon attached. The reaction mixture was stirred at RT for 2 h before it was filtered through a pad of Celite®, washed with methanol, and concentrated in vacuo to give the title compound. MS (ES+): 165 (M+H)+.

1. additionwas added
2. temperaturewarmed to RT for 2 h
3. additionadded to a separation funnel
4. custompartitioned with 3 N HCl (aqueous)
5. washwashed 3× with 50 mL of 3 N HCl (aqueous)
6. customseparated, before the aqueous layer
7. extractionwas extracted 3× with chloroform/isopropanol
8. dry with materialdried over sodium sulfate
9. concentrationconcentrated in vacuo

ORD record

ord-153cd221f35048c0bf7c8b75dff3ce78

Source dataset

uspto-grants-2010_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07759337B2