Sodium Hydroxide → HCID 44301326, compound

Participants

Reaction Steps

Trans-5,7-dichloro-2,4-dimethoxycarbonyl-1,2,3,4-tetrahydroquinoline (1.13 g) was dissolved in 50% aqueous methanol (80 ml) and sodium hydroxide (0.16 g 1.1 molar equivalents) was added. The solution was stirred at room temperature for 4 h then concentrated in vacuo and redissolved in water (40 ml). The aqueous solution was washed with diethyl ether (2×20 ml) then acidified to pH 1 with 1N hydrochloric acid and extracted into diethyl ether (2×50 ml), dried (Na2SO4), filtered and the solvent evaporated to give an oil. This was purified by chromatography on silica gel with 2.5% methanol, 0.5% acetic acid and 97% dichloromethane as eluent to give, as a colourless solid, trans-2-carboxy-5,7-dichloro-4-methoxycarbonyl-1,2,3,4-tetrahydroquinoline (0.85 g, m.p. 160° C. dec); δ (360 MHz, DMSO), 1.91 (1H, ddd, J=13.4, 11.7 and 6.0 Hz, CHACHBHCCHD), 2.41 (1H, dm, J=13.4 Hz, CHACHBHCCHD), 3.65 (3H, s, CH3), 3.79 (1H, dd, J=11.7 and 3.2 Hz, CHACHBHCCHD), 3.96 (1H, dd, J=6.0 and 2.5 Hz, CHACHBHCCHD), 6.66 (1H, d, J=2.1 Hz. 6-H or 8-H), 6.83 (1H, d, J=2.1 Hz, 6-H or 8-H); m/e 303 (M+) 198 (M-H, CO2H, CO2Me); Found: C, 47.31; H, 3.70; N. 4.57. C12H11Cl2NO4 requires C, 47.39; H, 3.65; N, 4.61%.

Provenance & Evidence