1,1'-Carbonyldiimidazole → HCID 67387571, compound

Participants

Reaction Steps

A mixture of 29 (91 mg, 0.14 mmol) and 1,1′-carbonyldiimidazole (CDI) (47 mg, 0.29 mmol) in dry THF (7 mL) was heated at reflux for 2 h under nitrogen. LCMS analysis shows one peak of the intermediate (RT=5.37). Optionally, the azalactone derivative, if desired, can be isolated. The reaction mixture was cooled to room temperature and cyclopropylsulfonamide (52 mg, 0.43 mmol) was added. Then, DBU (50 μL, 0.33 mmol) was added and the reaction mixture was stirred at room temperature for 1 h, and then heated at 55° C. for 24 h. The solvent was evaporated, and the residue partitioned between AcOEt ethyl acetate and acidic water (pH=3). The crude material was purified by column chromatography (ethyl acetateAcOEt/CH2Cl2/pPetroleum ether, 1:1:1). The residue was crystallized in diethyl ether, filtered to give the target compound contaminated with the cyclopropylsulfonamide. This material was triturated in 3 mL of water, filtered, washed with water and dried overnight with the high vacuum pump to give 60 mg (57%) of the target compound 30 as a slightly yellow powder: m/z=734 (M+H)+, 1H-NMR (CDCl3): 10.94 (s, 1H), 8.08 (d, J=8.6 Hz, 1H), 8.00 (s, 1H), 7.12-7.15 (m, 2H), 6.91 (s, 1H), 6.35 (s, 1H), 5.74-5.77 (m, 1H), 5.63-5.69 (m, 1H), 5.06 (t, J=10.4 Hz, 1H), 4.60 (t, J=12.3 Hz, 1H), 3.93 (s, 3H), 3.35-3.42 (m, 2H), 3.04 (s, 3H), 2.89-2.96 (m, 2H), 2.52-2.52 (m, 2H), 2.37-2.45 (m, 2H), 2.10-2.32 (m, 2H), 1.61-1.93 (m, 4H), 1.3-1.51 (m, 4H), 0.90-1.30 (m, 8H).

Provenance & Evidence