Isobutylene → HCID 86747051, compound

Participants

Reaction Steps

Trans-2-carboxy-4-methoxycarbonylmethyl-5,7-dichloro-1,2,3,4-tetrahydroquinoline (Example 156) (4 g) was suspended in dichloromethane (50 ml) and isobutylene (50 ml) was condensed at 0° C. Concentrated sulphuric acid (10 drops) was added and the reaction mixture was shaken for 3 days under a nitrogen atmosphere of 30 p.s.i. The solution was poured into saturated sodium hydrogen carbonate solution and diluted with a further amount of dichloromethane (100 ml). The organic layer was separated and the aqueous solution was washed with diethyl ether (100 ml). The combined organic layers were dried (Na2SO4), filtered and concentrated under vacuum. The residue obtained was purified by chromatography on silica gel with 20% hexane in dichloromethane as eluent to give the title compound as a colourless oil (4.07 g); δ (250 MHz, DMSO) 1.45 (9H, s, (CH3)3C), 1.64 (1H, ddd, J=13.0, 12.4 and 4.0 Hz, CHACHBHCCHD), 2.10 (1H, dm, J=13.0 Hz, CHACHBHCCHD), 2.49 (2H, m, CHECHFCO2CH3), 3.44 (1H, m, CHACHBHCCHDCHEHFCO2CH3), 3.65 (3H, s, CO2CH3), 3.97 (1H, dd, J=12.4 and 3.4 Hz, CHACHBHCCHD), 6.63 (2H, m, 6-H or 8-H and NH), 6.79 (1H, d, J=2.0 Hz, 6-H or 8-H); m/e (FAB) 374 (M+1); Found C, 54.93; H, 5.67; N, 3.69. C17H21Cl2NO4 requires C, 54.56; H, 5.66; N, 3.74%.

Provenance & Evidence