反应详情

温度

0 °C

To 2,4-difluoro-3-methylaniline (20 g) are added 42% tetrafluoroboric acid (56 ml) and water (28 ml) under ice cooling and thereto a solution of sodium nitrite (10 g) in water (20 ml) is added dropwise at below 10° C. After dropwise addition, the mixture is stirred at 0° C. for 15 minutes and the formed crystals are filtered, which is washed with a mixture of ethanol--diethyl ether (1:2), then with diethyl ether, followed by drying under reduced pressure to give 2,4-difluoro-3-methylbenzene diazonium tetrafluoroborate (28.95 g), m.p. 114-115° C.

1. additionAfter dropwise addition
2. filtrationthe formed crystals are filtered
3. washwhich is washed with a mixture of ethanol--diethyl ether (1:2)
4. customby drying under reduced pressure