反应详情

0.72 g of 1-(3-chloro-5-trifluoromethyl-pyridin-2-yl)-cyclopropanecarbaldehyde (step 2) was dissolved in 13 ml of tetrahydrofuran, then 1.32 g of titanium(IV)ethoxide and 355 mg of 2-methyl-propane-2-sulfinic acid amide were added to the solution. The reaction mixture was stirred at ambient temperature for 24 hours, then poured into brine. The resulting suspension was filtered, the filtrate extracted with ethyl acetate, the organic phase dried over sodium sulfate, filtered and concentrated. The residue was purified by chromatography on silica gel with cyclohexane/ethyl acetate (95:5) as eluent. Thus, 0.73 g of 2-methyl-propane-2-sulfinic acid 1-[1-(3-chloro-5-trifluoromethyl-pyridin-2-yl)-cyclopropyl]-methylideneamide was obtained as a pale yellow solid. 1H-NMR (CDCl3): 8.73 ppm (s, 1H), 7.95 ppm (s, 1H), 7.65 ppm (s, 1H), 1.70 ppm (m, 4H), 1.12 ppm (s, 9H).

1. filtrationThe resulting suspension was filtered
2. extractionthe filtrate extracted with ethyl acetate
3. dry with materialthe organic phase dried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. customThe residue was purified by chromatography on silica gel with cyclohexane/ethyl acetate (95:5) as eluent