[Cl:1][C:2]1[CH:8]=[C:7]([Cl:9])[CH:6]=[C:5]([N+:10]([O-])=O)[C:3]=1[NH2:4].Cl[Sn]Cl.C(O)C.C([O-])(O)=O.[Na+]>C(OCC)(=O)C>[Cl:1][C:2]1[C:3]([NH2:4])=[C:5]([NH2:10])[CH:6]=[C:7]([Cl:9])[CH:8]=13,5-Dichloro-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 2,4-dichloro-6-nitroaniline (1.00 g, 4.8 mmol) and SnCl2 °2H2O (5.41 g, 24.1 mmol) dissolved in 10 mL ethyl acetate and 5 mL absolute ethanol under N2 was heated at 70° C. for 1 h. All the starting material had reacted as evidenced by TLC (silica gel, 3:1 hexanes:ethyl acetate). The reaction was allowed to cool to room temperature and poured into 40 mL crushed ice. Sufficient sat'd NaHCO3 solution was added (foaming ) to bring the pH to 5. The orange oil/thick white emulsion was 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 pale orange oil which crystallized on standing to yield 789 mg (93%). 1H NMR (CDCl3) δ3.69 (br s, 4H, 2(NH2)); 6.61 (s, 1H, H-6); 6.82 (s, 1H, H-4).
Wird geladen…
