1,1'-Carbonyldiimidazole → HCID 73231858, compound

Participants

Reaction Steps

A solution of 16 (120 mg, 0.23 mmol) and carbonyldiimidazole (44 mg, 0.27 mmol) in dry THF (25 mL) was refluxed for 3 h under nitrogen. Optionally, the azalactone derivative, if desired, can be isolated. Then, the reaction mixture was cooled to room temperature and cyclopropylsulfonamide (33 mg, 0.27 mmol) and DBU (52 mg, 0.34 mmol) were added. The reaction mixture was heated at 50° C. for 24 h, then cooled down at room temperature and partitioned between water and CH2Cl2. The organic layers were dried (MgSO4), filtered, and the solvent was evaporated. The crude material was purified by column chromatography on silica gel (CH2Cl2/EtOAc, 95:05) to give a solid which was successively triturated in water, filtered, dried, triturated in ether and dried again under high vacuum to give 23 mg (16%) of the title product 17 as a white powder: m/z=530 (M+H)+; 1H NMR (CDCl3): 8.10 (d, J=9.3 Hz, 1H), 7.50 (s, 1H); 7.39 (s, 1H); 7.25 (dd, J=9.3 Hz, 2.5 Hz, 1H); 7.39-7.30 (bs, 1H); 5.90-5.83 (bs, 1H); 5.71 (dd, J=8.0 Hz, 17.9 Hz, 1H); 5.18 (t, J=10.1 Hz, 1H), 4.79 (dd, J=7.3 Hz, 9.0 Hz, 1H), 4.1 (s, 3H), 4.09-3.97 (m, 1H), 3.81-3.66 (m, 2H), 3.62 (d, J=11.6 Hz, 1H), 3.19-3.05 (m, 1H); 2.59-2.22 (m, 4H); 2.01-1.90 (m, 1H), 1.89 (dd, J=5.8 Hz, 8.6 Hz, 1H), 1.70 (dd, J=6.1 Hz, 9.8 Hz, 1H), 1.67-1.58 (m, 2H), 1.75-0.76 (m, 7H).

Provenance & Evidence