反应详情

A mixture of 4.203 g (25 mmol) of ethyl 4,4,4-trifluoro-crotonate, 20 mL of nitromethane and ca. 0.576 g (5 mmol) of tetramethyl guanidine was stirred for 13 h at room temperature, and then diluted with water and acidified by the addition of 0.5 M sulfuric acid. The mixture was extracted three times with diethyl ether. The combined ether extracts were washed with water, and then brine, dried over anhydrous sodium sulfate, filtered and concentrated under reduced pressure. to give 5.601 g (98%) of 4,4,4-trifluoro-3-nitromethyl-butyric acid ethyl ester as an amber oil. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.21 (t, J=7.15 Hz, 3H) 2.76 (dd, J=6.53, 1.76 Hz, 2H) 3.61-3.84 (m, 1H) 4.13 (q, J=7.11 Hz, 2H) 4.83-5.01 (m, 2H).

1. extractionThe mixture was extracted three times with diethyl ether
2. washThe combined ether extracts were washed with water
3. dry with materialbrine, dried over anhydrous sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated under reduced pressure