反应详情

温度

100 °C

1750 ml of N-methylpyrrolidone are initially introduced into a 10 1 four-necked flask having a dropping funnel, reflux condenser, internal thermometer and stirrer. 291.5 g (2.75 mol) of sodium carbonate are added to this. 372.5 g (2.5 mol) of 5-aminobenzimidazolone are then added at about 25° C. 3181.8 g of 3-hydroxy-2-naphthoyl chloride (from 494.0 g (2.63 mol) of 3-hydroxy-2naphthoic acid) in xylene are metered into the suspension thus obtained with stirring in the course of 6.5 h at 25°-28° C. After addition is complete, the mixture is subsequently stirred at room temperature for 30 min. The precipitated product is filtered off with suction (suction time: 50 min) and the filter cake is washed in 10 portions with a total of 2150.0 g=2500 ml of xylene. 2500 ml of water are initially introduced into a 6 l four-necked flask having a stirrer, internal thermometer and distillation bridge having a 1 l one-necked flask as a receiver. The filter cake is then introduced. 200.0 g of sodium carbonate are then added and the mixture is heated to 100° C. Xylene and water distill off. The product is filtered off with suction at 100° C. and the suction filter cake is washed several times with a total of 6250 ml of water until neutral. 1571.4 g of naphthalone are obtained in water-moist form. After drying the filter cake at 100° C./100 mmHg, 681.7 g (2.135 mol) of 3-hydroxy-N-benzimidazolon-5-yl-2naphthamide are obtained; this corresponds to a yield of 85.4% of theory based on 5-aminobenzimidazolone.

1. temperaturereflux condenser
2. customthus obtained
3. additionAfter addition
4. stirringthe mixture is subsequently stirred at room temperature for 30 min
5. filtrationThe precipitated product is filtered off with suction (suction time: 50 min)
6. washthe filter cake is washed in 10 portions with a total of 2150.0 g=2500 ml of xylene
7. addition2500 ml of water are initially introduced into a 6 l four-necked flask
8. distillationinternal thermometer and distillation bridge
9. additionThe filter cake is then introduced
10. addition200.0 g of sodium carbonate are then added
11. distillationXylene and water distill off
12. filtrationThe product is filtered off with suction at 100° C.
13. filtrationthe suction filter cake
14. washis washed several times with a total of 6250 ml of water until neutral