Methyl chloroformate → HCID 178502720, compound

To a solution of cis-4-{[(tert-butoxycarbonyl)amino]methyl}-cyclohexanecarboxylic acid (18.53 g, 72.0 mmol) and N-methylpiperidine (21.9 ml, 17.8 g, 180 mmol) in methylene chloride (360 ml) under nitrogen cooled in an ice-bath was adde dropwise methyl chloroformate (6.13 ml, 7.48 g, 79.2 mmol). The solution was stirred 15 minutes with cooling, and O,N-dimethylhydroxylamine hydrochloride (8.43 g, 86.4 mmol) was added. The mixture was stirred 18 hours while warming from ice-bath temperature to ambient temperature. The mixture was washed with 10% citric acid solution (100 ml), saturated sodium carbonate solution (100 ml), water (100 ml), and brine (100 ml), dried (sodium sulfate), filtered, and the solvent evaporated under reduced pressure to give crude product (15.30 g, 71%) as a yellow oil. The crude product was purified by flash column chromatography on silica gel, eluting with a gradient of 50:50 to 75:25 ethyl acetate/hexane to give tert-butyl [(cis-4-{[methoxy(methyl)amino]carbonyl}cyclohexyl)methyl]carbamate (13.76 g, 64%) as a pale yellow oil. 1H NMR (CDCl3) 4.61 (1H, br s), 3.68 (3H, s), 3.17 (3H, s), 3.11 (2H, t, J 6.5 Hz), 2.79 (1H, m), 1.75 (3H, m), 1.68-1.52 (6H, m), 1.44 (9H, s).

1. temperaturewith cooling
2. stirringThe mixture was stirred 18 hours
3. washThe mixture was washed with 10% citric acid solution (100 ml), saturated sodium carbonate solution (100 ml), water (100 ml), and brine (100 ml)
4. dry with materialdried (sodium sulfate)
5. filtrationfiltered
6. customthe solvent evaporated under reduced pressure
7. customto give crude product (15.30 g, 71%) as a yellow oil
8. customThe crude product was purified by flash column chromatography on silica gel
9. washeluting with a gradient of 50:50 to 75:25 ethyl acetate/hexane

ORD record

ord-e9822f0e281644199e89a3fecf875a60

Source dataset

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07452893B2