반응 #82568

반응 방정식

4,5-difluoro-1,2-diaminobenzene

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

SnCl2

NaHCO3

→

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

용매

H2O

ethyl acetate

ethanol

반응 조건

후처리

1. 1
   workup.ADDITIONwas added (foaming!)
2. 2
   추출The resulting mixture was extracted with 3×20 mL ethyl acetate
3. 3
   세척the combined organic extracts washed with 20 mL
4. 4
   건조The organic phase was dried (MgSO4), vacuum
5. 5
   여과filtered
6. 6
   기타the solvent rotary evaporated
7. 7
   기타to yield a brown solid, 124 mg (91%)

실험 절차

3-Chloro-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-chloro-3,4-difluoro-6-nitroaniline (160 mg, 0.767 mmol) and SnCl2 2H2O (0.863 g, 3.84 mmol) was dissolved in 5 mL ethyl acetate and 2 mL absolute ethanol under N2 and heated at 75° C. for 5 h. The reaction was allowed to cool to room temperature and poured into 50 mL H2O. Sufficient sat'd NaHCO3 solution was added (foaming!) to bring the pH to 7. The resulting mixture was extracted with 3×20 mL ethyl acetate and the combined organic extracts washed with 20 mL sat'd NaCl solution. The organic phase was dried (MgSO4), vacuum filtered and the solvent rotary evaporated to yield a brown solid, 124 mg (91%). 1H NMR (CDCl3) δ3.52 (br s, 4H, 2(NH2)); 6.49 (dd, 1H, JHF =7.5, 10.8 Hz, H-6). There was 13% 4,5-difluoro-1,2-diaminobenzene present by NMR.

출처