반응 #82571

반응 방정식

NaHCO3

2-bromo-3,4-difluoro-6-nitroaniline

SnCl2.2H2O

ethanol

→

3-Bromo-4,5-difluoro-1,2-diaminobenzene

용매

—

hexanes

ethyl acetate

ethyl acetate

반응 조건

후처리

1. 1
   기타All the starting material had reacted
2. 2
   workup.ADDITIONpoured into 20 mL
3. 3
   기타crushed ice
4. 4
   workup.ADDITIONwas added (foaming!)
5. 5
   추출The thick yellow white emulsion was then extracted with 3×25 mL ethyl acetate
6. 6
   세척the combined organic extracts washed with sat'd NaCl solution
7. 7
   건조The organic phase was dried (MgSO4), vacuum
8. 8
   여과filtered
9. 9
   기타the solvent rotary evaporated
10. 10
    기타to yield a dark brown oil which
11. 11
    기타crystallized
12. 12
    기타to yield 410 mg (66%)

실험 절차

3-Bromo-4,5-difluoro-1,2-diaminobenzene was prepared using an adaptation of the method of Bellamy et al. (Bellamy, F. D. et al., Tetrahedron Lett. 25:839 (1984)). A mixture of 2-bromo-3,4-difluoro-6-nitroaniline (700 mg, 2.78 mmol) and SnCl2.2H2O (3.14 g, 13.9 mmol) dissolved in 7 mL ethyl acetate and 3 mL absolute ethanol under N2 was heated at 75° C. for 2 h. All the starting material had reacted as evidenced by TLC (silica gel, 2:1 hexanes:ethyl acetate). The reaction was allowed to cool to room temperature and poured into 20 mL crushed ice. Sufficient sat'd NaHCO3 solution was added (foaming!) to bring the pH to 5. The thick yellow white emulsion was then extracted with 3×25 mL ethyl acetate and the combined organic extracts washed with sat'd NaCl solution. The organic phase was dried (MgSO4), vacuum filtered and the solvent rotary evaporated to yield a dark brown oil which crystallized on standing to yield 410 mg (66%). 1H NMR (CDCl3) δ3.59 (br s, 4H, 2(NH2)); 6.52 (m, 1H, H-6).

출처