Carbamic acid, N-(2,2-dimethyl-3-oxocyclobutyl)-, 1,1-dimethylethyl ester → HCID 131733579, compound

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Reaction Steps

To a solution of tert-butyl (2,2-dimethyl-3-oxocyclobutyl)carbamate (1.0 equiv.) in anhydrous THF (0.15 M) under nitrogen was added methyllithium (1.6 M in ether, 4.0 equiv.) drop-wise, keeping the temperature below −70° C. The mixture was stirred at this temperature for 1 h. The mixture was quenched with aqueous solution of ammonium chloride and the mixture was extracted with ethyl acetate, washed with aqueous solution of sodium bicarbonate and brine, dried over anhydrous sodium sulfate and filtered. The filtrate was concentrated under vacuum, the residue was purified by silica gel column chromatography (5% to 25% ethyl acetate in petroleum ether) to afford the title product (30% yield). 1H NMR (400 MHz, CDCl3) δ (ppm) 4.65-4.52 (m, 1H), 3.60-3.49 (m, 1H), 2.37-2.28 (m, 1H), 1.84-1.76 (m, 1H), 1.66 (s, 1H), 1.44 (s, 9H), 1.28 (s, 3H), 1.06 (s, 3H), 1.01 (s, 3H); MS (ESI) m/z 230.2 [M+H]+.

Provenance & Evidence