Reaction #992723
ord-f36be9597caa4ecda1ae13734173d8ec
Reaction equation
Reactants
Reagents
Solvents
Conditions
Workup
- 1Temperaturewas heated
- 2Temperatureat reflux for 2 h under nitrogen
- 3Otherone peak of the intermediate (RT=5.37)
- 4Othercan be isolated
- 5Temperatureheated at 55° C. for 24 h
- 6OtherThe solvent was evaporated
- 7Otherthe residue partitioned between AcOEt ethyl acetate and acidic water (pH=3)
- 8OtherThe crude material was purified by column chromatography (ethyl acetateAcOEt/CH2Cl2/pPetroleum ether, 1:1:1)
- 9OtherThe residue was crystallized in diethyl ether
- 10Filtrationfiltered
- 11Otherto give the target compound
- 12OtherThis material was triturated in 3 mL of water
- 13Filtrationfiltered
- 14Washwashed with water
- 15Otherdried overnight with the high vacuum pump
Procedure
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).