4-Nitrobenzyl chloroformate → HCID 18677664, compound

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Reaction Steps

A portion of the crude 4-(allylamino)-1-(tert-butoxycarbonyl)piperidine (400 mg, 1.66 mmol) was dissolved in 10 mL of dichloromethane and treated with N,N-diisopropylethylamine (0.700 mL, 519 mg, 4.0 mmol) and 4-nitrobenzyl chloroformate (392 mg, 1.82 mmol). After stirring 3 h at RT, the mixture was diluted with 30 mL of ethyl acetate and washed with 15 mL each of 2 N aqueous HCl, saturated aqueous sodium bicarbonate, and brine. The organic layer was dried over sodium sulfate, and evaporated. The residue was purified by flash column chromatography on silica gel, eluting with 30% ethyl acetate in hexane, to give 572 mg of the title compound as a colorless syrup. 1H NMR (400 MHz, CDCl3): δ 8.22 (d, 2H, J=8 Hz), 7.50 (d, 2H, J=8 Hz), 5.80 (ddt, 1H, J=17, 10, 5 Hz), 5.23 (s, 2H), 5.18-5.09 (m, 2H), 4.27-4.08 (m, 3H), 3.89-3.79 (m, 2H), 2.79-2.66 (m, 2H), 1.74-1.52 (m, 4H), 1.46 (s, 9H). Mass spectrum (ESI): m/z=420 (M+1, 27%), 437 (M+1+NH3, 100%).

Provenance & Evidence