反应详情

温度

-78 °C

To a solution of 5-bromo-2,4-bis-trifluoromethyl-pyridine (200 mg, 0.685 mmol) in dry diethyl ether (1.5 ml) at −78° C. was added a 2.5 M solution of n-butyllithium in hexane (0.25 ml, 0.685 mmol) and the mixture was stirred at −78° C. for 15 min. A solution of (S)-2-methyl-propane-2-sulfinic acid propylideneamide (Comp. No. 13b) (85 mg, 0.527 mmol) in dry toluene (1 ml) was added at −78° C., the mixture was stirred for 5 min at −78° C. and then poured into a saturated aqueous ammonium chloride solution. The mixture was extracted 3 times with dichloromethane, dried over sodium sulfate, and after evaporation of all solvents the crude product was purified by flash chromatography (silica gel, elution with heptane/ethyl acetate) to give 27 mg (14%) of (S)-2-methyl-propane-2-sulfinic acid [(S)-1-(4,6-bis-trifluoromethyl-pyridin-3-yl)-propyl]-amide (LC/MS (method 2; MS ionization method ES−): Rt=1.3 min; m/z=375.1 (M+1−)) and 29 mg (15%) of (S)-2-methyl-propane-2-sulfinic acid [(R)-1-(4,6-bis-trifluoromethyl-pyridin-3-yl)-propyl]-amide (LC/MS (method 2; MS ionization method ES−): Rt=1.3 min; m/z=375.12 (M+1−)).

1. stirringthe mixture was stirred for 5 min at −78° C.
2. extractionThe mixture was extracted 3 times with dichloromethane
3. dry with materialdried over sodium sulfate
4. customafter evaporation of all solvents the crude product
5. customwas purified by flash chromatography (silica gel, elution with heptane/ethyl acetate)