反应详情

A mixture of (2) (182 mg, 0.32 mmol) and CDI (139 mg, 0.29 mmol) in dry THF (10 mL) was heated at reflux for 1.5 h under nitrogen. LCMS analysis showed one peak of the intermediate (2-1) (a stable intermediate, which can be isolated by purification on silica gel). The reaction mixture was cooled to room temperature and cyclopropyl-sulfonamide (93 mg, 0.76 mmol) was added. Then, DBU (138 mg, 0.91 mmol) was added. The reaction mixture was stirred at room temperature for 1 h, then heated at 55° C. for 12 h. Next, the solvent was evaporated, and the residue partitioned between ethyl acetate and acidic water (pH=3). The organic layer was dried (Na2SO4) and evaporated. The crude material was purified by column chromatography (ethyl acetate/CH2Cl2, 1:9). The residue was sonicated in water for 1 h, filtered off and washed with isopropylether to give the title product (3) as a white powder: m/z=669 (M+H)+. 1H NMR (CDCl3): 0.90-1.30 (m, 5H), 1.31-1.52 (m, 6H), 1.61-1.72 (m, 1H), 1.73-1.99 (m, 3H), 2.09-2.20 (m, 1H), 2.30-2.42 (m, 2H), 2.48-2.62 (m, 5H), 2.70-2.83 (m, 1H), 3.01 (s, 3H), 3.30-3.41 (m, 2H), 3.94 (s, 3H), 4.50-4.73 (m, 3H), 5.05 (t, J=10.0 Hz, 2H), 5.62-5.69 (m, 1H), 5.95 (s, 1H), 6.35 (br s, 1H), 7.01 (d, J=9.1 Hz, 1H), 7.85 (d, J=9.1 Hz, 1H), 10.8 (br s, 1H).

1. temperaturewas heated
2. temperatureat reflux for 1.5 h under nitrogen
3. customcan be isolated by purification on silica gel)
4. temperatureheated at 55° C. for 12 h
5. customNext, the solvent was evaporated
6. customthe residue partitioned between ethyl acetate and acidic water (pH=3)
7. dry with materialThe organic layer was dried (Na2SO4)
8. customevaporated
9. customThe crude material was purified by column chromatography (ethyl acetate/CH2Cl2, 1:9)
10. customThe residue was sonicated in water for 1 h
11. filtrationfiltered off
12. washwashed with isopropylether