Tert-Butanesulfinamide → N-(5'-Bromo-4-(trifluoromethyl)spiro[cyclohexane-1,2'-indene]-3'(1'H)-ylidene)-2-methylpropane-2-sulfinamide

Participants

Reaction Steps

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): 1H NMR (400 MHz, CDCl3) δ ppm 1.34-1.37 (m, 9 H) 1.56 (s, 4 H) 1.73-1.82 (m, 2 H) 2.13 (br. s., 5 H) 2.89 (d, 2 H) 7.22 (d, 1 H) 7.60 (dd, 1 H) 8.53 (d, 1 H); MS (ES+) 451 [M+H]+.

Provenance & Evidence