Reaction Steps
A suspension of quindoline (1.0 g, 4.6 mmol) from Example 2, benzyl bromide (3 mL, 8.5 mmol) and chloroform (5 mL) was heated in a bomb at 140° C. for 48 hours. After cooling, the reaction mixture was dissolved in a small amount chloroform. Ether (100 mL) was added, and the resulting precipitate was filtered and washed with ether to give 1.78 g (100%) of 5-benzylquindolinium hydrobromide as a greenish-yellow solid. A portion of the 5-benzyl quindolinium hydrobromide (0.9 g) obtained above was purified by LPLC on neutral alumina (Fisher) eluting with 1-2% MeOH in CHCl3. The product containing fractions were combined, redissolved in a small amount of chloroform, and acidified with a solution of 1.0 M HCl in ether to give, after filtration and drying, 0.20 g (25%) of 5-benzylquindolinium hydrochloride as yellow crystals, mp 241-242° C.; 1H NMR (DMSO-d6) δ 13.40 (s, 1H, NH), 9.49 (s, 1H, H11), 8.68 (d, J=8.2, 1H, H6), 8.53 (d, J=8.8, 1H, H4), 8.31 (d, J=8.4, 1H, H1), 8.12 (t, J=6.4, 1H, H3), 7.96 (t, J=7.6, 1H, H8), 7.90 (d, J=5.2, 2H, H2 and H9), 7.42-7.32 (m, 4H, H7 and arom), 7.22 (d, J=6.4, 2H), 6.84 (s, 2H, NCH2); 13C NMR (DMSO-d6) δ 146.14, 138.11, 135.21, 134.16, 133.84, 133.28, 133.00, 130.23, 129.19, 128.14, 127.21,126.41, 126.10, 126.02, 125.24, 121.65, 117.59, 113.53, 112.86; MS (EI, m/z) 308.1 (M+ -1)
