Dimethylacetamide → Carbamic acid, N-[(1R,2S)-1-[[(cyclopropylsulfonyl)amino]carbonyl]-2-ethenylcyclopropyl]-, 1,1-dimethylethyl ester

Participants

Reaction Steps

To a stirring solution of 500 mg (1R,2S)-1-BOC-amino-2-vinylcyclopropane carboxylic acid (2.2 mmol) in 4 mL of DMA (N,N-dimethylacetamide), was added 370 mg of carbonyl diimidazole (CDI, 2.3 mmol). The reaction mixture was stirred at RT for 1 hr, followed by addition of 280 mg of cyclopropylsulfonamide (2.3 mmol), 1 mL of diisopropylethylamine and 350 uL of DBU. The resulting mixture was stirred at 60° C. overnight. The solvent was removed, and normal workup was applied with 100 mL of EtOAc, washed with 10 mL of 1.0 N aqueous HCl, dried over anhydrous Na2SO4. After concentration, the residue was purified by flash column chromatography giving 580 mg of white solid. 1HNMR (CDCl3, 400 MHz) δ 9.7 (br s, 1H), 5.61 (m, 1H), 5.33 (br dd, 2H, J=9.6, 1.2 Hz), 5.18 (dd, J=9.6, 1.2 Hz), 2.92 (m, 1H) 2.14 (q, 1H, J=8.0 Hz), 1.91 dd, 1H, J=8.4, 2.4 Hz), 1.55 (br s, 2H), 1.47 (s, 9H), 1.40 (m, 2H), 1.30 (m, 2H), 0.95-1.15 (m, 2H). LC/MS: m/z 329.1, (M−1, ES−).

Provenance & Evidence