1,1'-Carbonyldiimidazole → tert-butyl [(1R,2S)-2-ethenyl-1-{[(1-methylcyclopropyl)sulfonyl]carbamoyl}cyclopropyl]carbamate

Participants

Reaction Conditions

Reaction Steps

To a solution of (1R,2S)-1-(tert-butoxycarbonylamino)-2-vinylcyclopropanecarboxylic acid (25 g, 110 mmol) in THF (300 mL) was added CDI (205 g, 127 mmol) and the reaction mass was heated at 85° C. for 1 h. The reaction mass was cooled to rt and to this reaction mass was added 1-methylcyclopropane-1-sulfonamide (17.7 g, 131 mmol) followed by DBU (33.2 mL, 33.5 mmol). The reaction mixture was stirred at rt for 18 h. The solvent was evaporated under reduced pressure and the residue was diluted with water and acidified to pH˜2 by using aq. 1.5 N HCl solution. The precipitated solid was isolated via filtration and washed with water to get desired compound (22 g, 58%) as off-white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 11.01-11.17 (m, 1H), 7.17-7.33 (m, 1H), 5.35-5.51 (m, 1H), 5.18-5.29 (m, 1H), 4.99-5.09 (m, 1H), 2.21 (s, 1H), 1.69 (dd, J=7.78, 5.27 Hz, 1H), 1.40 (d, J=3.01 Hz, 14H), 1.20 (dd, J=9.29, 5.27 Hz, 1H), 0.82-0.96 (m, 2H). MS: MS m/z 343 (M++1).

Provenance & Evidence