反应详情

温度

20 °C

α-Tetralone (51 g) is added dropwise in the course of 45 minutes, at a temperature in the region of 15° C., to a mixture of N-(3-dimethylamino-3-ethoxycarbonylpropenylidene)-N-methylmethanaminium tetrafluoroborate (100 g) in ethanol (500 cc) and a 2M ethanolic solution of sodium ethylate (210 cc). The mixture is maintained for 1 hour 45 minutes at a temperature in the region of 20° C. and is then heated for 4 hours 45 minutes to 70° C. The reaction ethanol is evaporated off to dryness and the oil obtained is pounded with ethyl ether (4×300 cc). The ethereal extracts are concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa). After recrystallization of the solid obtained in a boiling mixture (60 cc) of isopropyl ether and ethyl acetate (90:10 by volume), ethyl 2-dimethylamino-4-(1-oxo-1,2,3,4-tetrahydro-2-naphthylidene)-2-butenoate (17.5 g), m.p. 84° C., is obtained.

1. temperatureis then heated for 4 hours 45 minutes to 70° C
2. customis evaporated off to dryness
3. customthe oil obtained
4. concentrationThe ethereal extracts are concentrated to dryness under reduced pressure (20 mm Hg; 2.7 kPa)
5. customAfter recrystallization of the solid