反应详情

373 g of 2-amino-5-bromo-p-xylene were suspended in 1860 ml of H2O in a 4 l four-necked flask, the mixture was cooled to 3° C. (internal temperature), and 612 ml of tetrafluoroboric acid were added. 154 g of NaNO2 in 300 ml of water were then added dropwise over the course of 60 minutes. After 60 minutes, the solid was filtered off with suction and washed with a little cold 5% tetrafluoroboric acid, then with a little cold methanol and finally with a little cold diethyl ether. The yellow solid (497 g=90%) was dried overnight in an oil-pump vacuum.

1. additionwere added
2. filtrationthe solid was filtered off with suction
3. washwashed with a little cold 5% tetrafluoroboric acid
4. customThe yellow solid (497 g=90%) was dried overnight in an oil-pump vacuum