反应详情

温度

20 °C

Benzyl 4-(benzyloxy)-5-methoxy-2-nitrobenzoate (90 g) was charged to acetonitrile (660 g). 85% Sodium dithionite (75 g) was added to the solution and the temperature adjusted to 20° C. Water (516 g) was then added, maintaining the temperature at 20° C. The slurry was then heated to 65° C. and stirred for 30 minutes. Sodium dithionite (75 g) was added and the mixture stirred for another 30 minutes. The lower aqueous phase was removed. Concentrated hydrochloric acid (33% w/w, 12.48 g) was then added to adjust to a pH of <1. The suspension is held for 1 hour. The slurry was cooled to 20° C. over 30 minutes. Sodium hydroxide solution (20% w/w, 59.29 g) was added to give a pH of 10. The slurry was cooled to 0° C. and stirred for one hour. The product (benzyl 2-amino-4-(benzyloxy)-5-methoxybenzoate) was isolated by filtration, washed twice with water (2×222 ml) and then dried at 60° C. under vacuum. Yield: 78.81 g, 95%; NMR Spectrum (CDCl3) 3.8 (s, 3H), 5.1 (s, 2H), 5.3 (s, 2H), 6.2 (s, 1H), 7.3-7.4 (m, 10H); Mass Spectrum (M+H)+=364.1.

1. customadjusted to 20° C
2. temperatureThe slurry was then heated to 65° C.
3. stirringthe mixture stirred for another 30 minutes
4. customThe lower aqueous phase was removed
5. additionConcentrated hydrochloric acid (33% w/w, 12.48 g) was then added
6. waitThe suspension is held for 1 hour
7. temperatureThe slurry was cooled to 20° C. over 30 minutes
8. additionSodium hydroxide solution (20% w/w, 59.29 g) was added
9. customto give a pH of 10
10. temperatureThe slurry was cooled to 0° C.
11. stirringstirred for one hour