Ethyl chloroformate → HCID 71279990, compound

Participants

Reaction Conditions

Reaction Steps

In a 100 mL round bottomed flask cis-3-(tertbutoxycarbonylamino)-cyclohexanecarboxylic acid (2.26 g, 9.29 mmol) was suspended in THF (15 mL). The suspension was cooled to −10° C. in an acetone-dry ice bath. To the cooled suspension was added slowly TEA (2.6 mL, 18.7 mmol) and subsequently ethyl chloroformate (1.03 mL, 10.7 mmol) so that the temperature is maintained. The cooling bath was removed upon addition and the reaction was stirred at room temperature for 3 h. The reaction mixture was cooled to −10° C. and NH4OH (2.17 mL, 55.7 mmol) was added slowly. After stirring at room temperature for 18 h, the precipitate was collected by filtration. The precipitate was washed with water and dried in vacuo at 50° C. to afford 1.67 g (74%) of (cis-3-carbamoyl-cyclohexyl)-carbamic acid tert-butyl ester as a white solid. 1H NMR (300 MHz, DMSO-d6) δ: 7.19 (br. s., 1H), 6.76 (d, J=7.9 Hz, 1H), 6.65 (br. s., 1H), 3.04-3.30 (m, 1H), 1.98-2.21 (m, 1H), 1.50-1.84 (m, 4H), 1.37 (s, 9H), 0.90-1.29 (m, 4H)

Provenance & Evidence