反应详情

To a solution of 2-amino-5-nitro-phenol (500 g, 3.24 mol) in ACN (12 L) was added bromine (290 mL, 5.63 mol) drop wise over a period of 30 min under stirring. The resulting mixture was stirred at 30-35° C. for 1 h. After the completion of the reaction (by TLC), solvent was evaporated till dryness. Hexane was added (2 L) and the mixture evaporated to remove solvent traces. Hexane (5 L) was added again to the residue and the mixture stirred for 1 h then filtered. The resulting solid (1102 g) was washed with hexane (2 L). The residue was added to ice-cold water (2.5 L) followed by addition of a saturated solution of sodium thiosulfate (2.5 L) and extraction with EtOAc (2×10 L). The combined organic layers were washed with brine, dried (Na2SO4), filtered and concentrated at 40-45° C. under reduced pressure to obtain the desired product (643 g crude yield 85%).

1. stirringThe resulting mixture was stirred at 30-35° C. for 1 h
2. customAfter the completion of the reaction (by TLC), solvent
3. customwas evaporated till dryness
4. additionHexane was added (2 L)
5. customthe mixture evaporated
6. customto remove solvent traces
7. additionHexane (5 L) was added again to the residue
8. stirringthe mixture stirred for 1 h
9. filtrationthen filtered
10. washThe resulting solid (1102 g) was washed with hexane (2 L)
11. additionThe residue was added to ice-cold water (2.5 L)
12. additionfollowed by addition of a saturated solution of sodium thiosulfate (2.5 L) and extraction with EtOAc (2×10 L)
13. washThe combined organic layers were washed with brine
14. dry with materialdried (Na2SO4)
15. filtrationfiltered
16. concentrationconcentrated at 40-45° C. under reduced pressure