反应详情

Titanium ethoxide (2.03 mL, 9.85 mmol), 2-methyl-2-propanesulfinamide (0.895 g, 7.39 mmol) and 6′-bromo-4-(trifluoromethyl)spiro[cyclohexane-1,2′-inden]-1′(3′H)-one (Intermediate 78, 1.71 g, 4.93 mmol) in dry 2-Me THF (30 mL) were heated to 100° C. to give an azeotrope at 74° C. The azeotropic distillation was continued for 5 h and then the mixture was refluxed for 2 days. The mixture was cooled to r.t. Water (10 mL) and EtOAc (20 mL) were added, under continuous stirring, while a solid formed. The reaction mixture was stirred at r.t. for 2 h, and then the formed solid was left to sediment for 1 h. The mixture was filtered, and the solid was washed with EtOAc. The filtrate was concentrated in vacuo to give a residue that was purified by flash chromatography (eluent heptane/EtOAc 65/35) to give the title compound (400 mg, 18% yield):

1. customto give an azeotrope at 74° C
2. distillationThe azeotropic distillation
3. temperaturethe mixture was refluxed for 2 days
4. additionWater (10 mL) and EtOAc (20 mL) were added, under continuous stirring, while a solid
5. customformed
6. waitthe formed solid was left
7. waitto sediment for 1 h
8. filtrationThe mixture was filtered
9. washthe solid was washed with EtOAc
10. concentrationThe filtrate was concentrated in vacuo
11. customto give a residue that
12. customwas purified by flash chromatography (eluent heptane/EtOAc 65/35)