反应详情

To a solution of methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-3a-thioureido-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)benzoate (150 mg, 0.249 mmol) in DMF (5 mL) was added N,N-diisopropylethylamine (0.173 mL, 0.995 mmol) and 3-bromobutan-2-one (56.4 mg, 0.373 mmol). The reaction mixture was stirred at rt. After 18 h, the reaction mixture was poured into a separatory funnel containing H2O (10 mL) and extracted with EtOAc (50 mL). The organic layer was washed with brine, dried over MgSO4, filtered and concentrated to white solid. The material was redissolved in DCM (5 mL) and MeOH was added to effect precipitation. The mixture was concentrated to remove most of DCM and the resulting white precipitate was filtered, washed with cold MeOH, and dried in a vacuum oven to give methyl 4-((1R,3aS,5aR,5bR,7aR,11aS,11bR,13aR,13bR)-3a-(4,5-dimethylthiazol-2-ylamino)-5a,5b,8,8,11a-pentamethyl-1-(prop-1-en-2-yl)-2,3,3a,4,5,5a,5b,6,7,7a,8,11,11a,11b,12,13,13a,13b-octadecahydro-1H-cyclopenta[a]chrysen-9-yl)benzoate (121 mg, 0.175 mmol, 70.5% yield) as a white solid. LCMS: m/e 655.3 (M+H)+, 2.72 min (method 2). 1H NMR (500 MHz, CHLOROFORM-d) δ 7.95 (d, J=8.2 Hz, 2H), 7.21 (d, J=8.2 Hz, 2H), 5.31 (d, J=4.6 Hz, 1H), 4.76 (br. s., 1H), 4.65 (s, 1H), 3.93 (s, 3H), 2.43 (d, J=10.4 Hz, 1H), 2.21 (s, 3H), 2.15 (s, 3H), 2.11 (d, J=6.7 Hz, 1H), 2.07-1.96 (m, 1H), 1.80-1.65 (m, 6H), 1.57-1.36 (m, 8H), 1.35-1.27 (m, 2H), 1.23 (d, J=10.1 Hz, 1H), 1.17-1.11 (m, 1H), 1.09 (s, 3H), 1.03 (s, 3H), 1.00 (s, 3H), 0.94 (s, 6H).

1. additionthe reaction mixture was poured into a separatory funnel
2. extractionextracted with EtOAc (50 mL)
3. washThe organic layer was washed with brine
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated to white solid
7. dissolutionThe material was redissolved in DCM (5 mL)
8. additionMeOH was added to effect precipitation
9. concentrationThe mixture was concentrated
10. customto remove most of DCM
11. filtrationthe resulting white precipitate was filtered
12. washwashed with cold MeOH
13. customdried in a vacuum oven