Trifluoroacetic acid → HCID 18008930, compound

Participants

Reaction Steps

Trifluoroacetic acid (574 μl) was added to a stirred solution of 7-(2-ethoxycarbonyl-1-methyl-ethyl)-4-{[3-methoxy-4-(3-o-tolyl-ureido)-phenyl]-acetyl}-3,4-dihydro-2H-quinoxaline-1-carboxylic acid tert-butyl ester (376 mg, Reference Example 18) in dichloromethane (4 ml) at 0° C. After stirring at 0° C. for 2 hours a further aliquot of trifluoroacetic acid (3.5 ml) was added and stirring was continued at 0° C. for a further 4 hours. The reaction mixture was poured onto a mixture of ice (75 ml) and sodium hydroxide solution (55 ml, 1M). The resulting mixture was extracted three times with dichloromethane (50 ml). The combined extracts were washed twice with water (20 ml), then dried over magnesium sulfate and then evaporated (40 mbar, 40° C.). The residue was subjected to flash chromatography (20 g silica, 0.040-0.063 mm particle size) eluting with a mixture of dichloromethane and methanol (99:1, v/v) to give the title compound as a white powder (279 mg). TLC: RF=43/64 (dichloromethane:methanol, 9:1). 1H NMR (250 MHz, (CD3)2SO, at a temperature of 373° K.]: δ1.16 (t, J=7 Hz, 3H); 1.23 (d, J=7.5 Hz, 3H); 2.28 (s, 3H); from 2.45 to 2.55 (m, 2H); 3.06 (m, 1H); 3.25 (m, 2H); 3.69 (m, 2H); 3.82 (s, 2H); 3.85 (s, 3H); 4.05 (q, J=7 Hz, 2H); 5.73 (broad band :1H); 6.43 (dd, J=8 and 2 Hz, 1H); 6.50 (d, J=2 Hz, 1H); 6.70 (dd, J=9 and 1.5 Hz, 1H); 6.81 (d, J=1.5 Hz, 1H); 6.97 (broad t, J=7.5 Hz, 1H); from 7.10 to 7.30 (m, 3H); 7.71 (broad d, J=9 Hz, 1H); 7.98 (d, J=8.5 Hz, 1H); 8.25 (broad s, 1H); 8.29 (broad s, 1H). MS (EI): 544(M+).

Provenance & Evidence