反应详情

2-Amino-4-fluorobenzoic acid (25 g, 161.2 mmol) were suspended in 250 ml of water and 39 ml of conc. hydrochloric acid. At 0° C., sodium nitrite (11.2 g, 161.2 mmol) in 30 ml of water were added dropwise at below 10° C. After 30 min at room temp., sodium sulfite (69 g, 400 mmol) in 250 ml of water were added. After stirring for 2 h, 30 ml of conc. hydrochloric acid were added, and the mixture was left to stand overnight. It was then heated under reflux for 9 h, cooled and adjusted to pH 5.5 with sodium bicarbonate. The precipitate was filtered off with suction and dried.

1. waitthe mixture was left
2. waitto stand overnight
3. temperatureIt was then heated
4. temperatureunder reflux for 9 h
5. temperaturecooled
6. filtrationThe precipitate was filtered off with suction
7. customdried