Hydrochloric Acid → (2S)-2-Methylpiperidine-1-carbonyl chloride

To a pale yellow solution of triphosgene (742 mg, 2.50 mmol) and pyridine (0.404 mL, 5.00 mmol) in dry DCM (10 mL) at 10° C. under N2 was added (S)-2-methyl piperidine (Aldrich, 0.603 mL, 5.00 mmol) cautiously over 2 min. The vivid orange solution was stirred at RT for 18 h, then pyridine (0.404 mL, 5.00 mmol) and triphosgene (742 mg, 2.50 mmol) were added sequentially (CARE: exotherm on addition of triphosgene) and the orange solution stirred at RT for 4 h. Aqueous HCl solution (1M, 10 mL) was added and the mixture stirred vigorously until gas evolution ceased (30 min). The aqueous layer was extracted with DCM (10 mL), then the combined organics passed through a hydrophobic frit and concentrated in vacuo to leave the title compound as a dark red oil (745 mg, 92%). 1H NMR (300 MHz, CDCl3): 1.25 (3H, d, J 7.0), 1.42-1.77 (6H, m), 3.07 (1H, br s), 4.17 (1H, dd, J 13.8, 4.0), 4.62 (1H, apparent quin, J 6.3).

1. stirringthe orange solution stirred at RT for 4 h
2. stirringthe mixture stirred vigorously until gas evolution
3. custom(30 min)
4. extractionThe aqueous layer was extracted with DCM (10 mL)
5. concentrationconcentrated in vacuo

ORD record

ord-dd1e2ae9ab7e43f58c6fed0122842be3

Source dataset

uspto-grants-2014_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08907094B2