Synthesis
4-amino-7-chloroquinoline is obtained byreacting 7-chloro-4-hydrazinoquinoline ,sodium borohydride with nickel (II) chloride hexahydrate in methanol.To a suspension of 7-chloro-4-hydrazinoquinoline (1.67 g, 8.6 mmol) and nickel (II) chloride hexahydrate (2.00 g, 8.6 mmol) in methanol (33 ml), sodium borohydride (0.98 g, 25.8 mmol) was added cautiously while stirring the reaction mixture vigorously at room temperature and left to react overnight. The reaction mixture was filtered through celite pad. Water was used to dilute the filtrate layer and then washed with ethyl acetate. The organic layer was dried with magnesium sulphate and concentrated in vacuo to give the title compound as a yellow powder (1.09 g, 72%): mp: 143 – 147 ℃ (Lit.: 147 – 148 ℃) ;
vmax/cm-1 3337 s (N-H), 1642 m (C=N), 1609 m and 1575 m (C=N); δH (300 MHz; DMSO-d6) 8.28 (1H, d, J 5.3, C(2)H), 8.19 (1H, d, J 9.1, C(5)H), 7.76 (1H, d, J 1.6, C(8)H), 7.39 (1H, dd, J 9.1, 1.6, C(6)H), 7.03 (2H, s, NH2), 6.57 (1H, d, J 5.3, C(3)H); δC (75 MHz; DMSO-d6) 152.0 (Ar-C), 151.1 (C(2)H), 148.9 (Ar-C), 133.7 (Ar-C), 126.8 (C(8)H), 124.8 (C(5)H), 123.9 (C(6)H), 117.0 (Ar-C), 102.7 (C(3)H); m/z (-ES) 179 (100%, [M+H]- with 35Cl), 181 (35%, [M+H]- with 37Cl); found by +ES 179.0377, C9H8ClN2 ([M+H]+ with 35Cl), requires 179.0371, error 3.3 ppm.
