tert-Butylsulfinamide, (R)-(+)- → (R)-2-Methyl-propane-2-sulfinic acid [1-(4-bromo-2-methyl-phenyl)-ethylidene]-amide

Participants

Reaction Conditions

Reaction Steps

Titanium(IV) ethoxide (10.7 mL) was added to a solution of 1-(4-bromo-2-methyl-phenyl)-ethanone (4.41 g) and (R)-2-methyl-2-propanesulfinamide (2.76 g) in tetrahydrofuran (45 mL). The resulting solution was heated to 65° C. and stirred at this temperature for 20 h. Then, the solution was cooled to ambient temperature and another portion of titanium(IV) ethoxide (5.4 mL) and (R)-2-methyl-2-propane-sulfinamide (1.25 g) were added. After stirring the solution at 65° C. for another 12 h, the solution was cooled to ambient temperature and poured into brine. The resulting mixture was filtered over Celite and the organic phase of the filtrate was separated. The aqueous phase of the filtrate was extracted with ethyl acetate and the extracts were combined with the separated organic phase. The combined organic phases were washed with brine and dried (MgSO4) and the solvent was evaporated. The residue was chromatographed on silica gel (cyclohexane/ethyl acetate 9:1→1:1) to afford the title compound. Yield: 6.24 g (95% of theory); Mass spectrum (ESI+): m/z=316/318 (Br) [M+H]+.

Provenance & Evidence