反应详情

A solution, under an inert atmosphere, of 20.77 g of ethyl (2R)-2-(acetylamino)-3-(3-pyridyl)propanoate in 208 cm3 of anhydrous ethanol is cooled to a temperature in the region of 10° C., followed by portionwise addition of 8.31 g of sodium borohydride. The reaction mixture is stirred for 16 hours at room temperature. The ethanol is evaporated off under reduced pressure (2 kPa) at a temperature in the region of 40° C., to give 43.56 g of a pale yellow paste which is taken up and stirred in 50 cm3 of water. The solution, which has a pH in the region of 12, is cooled to a temperature in the region of 0° C. and then neutralized by dropwise addition of concentrated hydrochloric acid. The resulting mixture is stirred for 1 hour at this temperature and the white precipitate formed is then filtered off on a sinter funnel, then dried in an oven under vacuum (0.1 kPa) at a temperature in the region of 55° C. 11.15 g of N-[(1R)-2-hydroxy-1-(3-pyridylmethyl)ethyl]acetamide are obtained in the form of a white solid melting at a temperature above 260° C. The filtrate is extracted with 3 times 100 cm3 of ethyl acetate and the organic phases are then combined, dried over magnesium sulfate, filtered and evaporated under reduced pressure (2 kPa) at a temperature in the region of 40° C. 2.4 g of N-[(1R)-2-hydroxyl-1-(3-pyridylmethyl)ethyl]acetamide partially complexed with boron are obtained in the form of a white paste. [1H NMR spectrum (300 MHz, (CD3)2SO-d6, δ in ppm): 1.75 (s: 3H); 2.61 (dd, J=14 and 9 Hz: 1H); 2.88 (dd, J=14 and 5.5 Hz: 1H); from 3.20 to 3.45 (mt: 2H); 3.91 (mt: 1H); 4.82 (broad t, J=5 Hz: 1H); 7.30 (dd, J=7.5 and 5 Hz: 1H); 7.62 (dt, J=7.5 and 2 Hz: 1H); 7.72 (d, J=9 Hz: 1H); from 8.35 to 8.45 (mt: 2H)].

1. customThe ethanol is evaporated off under reduced pressure (2 kPa) at a temperature in the region of 40° C.
2. customto give 43.56 g of a pale yellow paste which
3. temperatureis cooled to a temperature in the region of 0° C.
4. stirringThe resulting mixture is stirred for 1 hour at this temperature
5. customthe white precipitate formed
6. filtrationis then filtered off on a sinter funnel
7. customdried in an oven under vacuum (0.1 kPa) at a temperature in the region of 55° C