CC(C)([O-])C.[K+].[CH2:7]([SH:14])[C:8]1[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1.[C:15]([O:19][C:20](=[O:31])[C:21]1[CH:26]=[CH:25][C:24]([CH:27]=[O:28])=[C:23](F)[C:22]=1[F:30])([CH3:18])([CH3:17])[CH3:16]>C1COCC1>[C:15]([O:19][C:20](=[O:31])[C:21]1[CH:26]=[CH:25][C:24]([CH:27]=[O:28])=[C:23]([S:14][CH2:7][C:8]2[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=2)[C:22]=1[F:30])([CH3:18])([CH3:16])[CH3:17]To a solution of potassium tert-butoxide (2.0 g, 17.9 mmol) in anhydrous THF (80 mL) was added benzyl mercaptan (2.1 mL, 17.9 mmol). The reaction mixture was stirred at room temperature for 5 minutes before being cooled to −30° C. A solution of 2,3-difluoro-4-formyl-benzoic acid tert-butyl ester (4.34 g, 17.9 mmol) in anhydrous THF (20 mL) was added dropwise over 15 minutes and the resultant mixture was stirred at −30° C. for 30 minutes before being quenched by addition of water and extracted with ethyl acetate. The organic layer was separated, washed with water followed by brine, dried (Na2SO4), filtered and evaporated in vacuo to give the title compound as a yellow oil (6.2 g, 100%). 1H NMR (CDCl3, 400 MHz) 10.20 (1 H, d, J=0.6 Hz), 7.84 (1 H, ddd, J=8.0, 6.8, 0.7 Hz), 7.59 (1 H, dd, J=8.0, 0.9 Hz), 7.19 (3 H, m), 7.05 (2 H, m), 4.07 (2 H, s), 1.63 (9 H, s).
Wird geladen…
