Reaction Steps
Piperidine (97 μL, 0.99 mmol) was added to a suspension of 3-((diethylamino)methyl)-4-methoxybenzaldehyde (0.22 g, 0.99 mmol) and 2-[(carboxyacetyl)amino]benzoic acid (0.20 g, 0.90 mmol) in toluene (5 mL) and treated according to Procedure 2, neutralizing with 20% AcOH. The resulting precipitate was filtered and washed with water providing (E)-2-[[3-(3-((diethylamino)methyl)-4-methoxyphenyl)-1-oxo-2-propenyl]amino]benzoic acid (0.17 g, 50%) as a colourless crystalline solid; mp 202-205° C.; δH (400 MHz, DMSO-d6) 1.14 (t, J=7.2 Hz, 4H, CH2CH3), 2.87 (q, J=7.2 Hz, 6H, CH2CH3), 3.79 (s, 3H, OCH3), 3.98 (s, 2H, NCH2), 6.51 (d, J=15.6 Hz, 1H, CH═CHCO), 6.98 (t, J3,4=J4,5=8.0 Hz, 1H, H4), 7.03 (d, J5′,6′=8.0 Hz, 1H, H5′), 7.34 (t, J4,5=J5,6=8.0 Hz, 1H, H5), 7.46 (d, J=15.6 Hz, 1H, CH═CHCO), 7.57 (dd, J5′,6′=8.0, J2′,6′=1.6 Hz, 1H, H6′), 7.76 (d, J2′,6′=1.6 Hz, 1H, H2′), 7.98 (d, J3,4=8.0 Hz, 1H, H3), 8.54 (d, J5,6=8.0 Hz, 1H, H6), 13.34 (br s, 1H, CO2H); δC (100 MHz, DMSO-d6) 9.38, 46.4, 49.8, 55.6, 111.4, 118.9, 121.2, 121.5, 122.1, 126.9, 130.2, 130.8, 130.9, 139.2, 140.7, 158.8, 163.3, 169.7; HRMS (ESI) calculated for C22H26N2O4 [M+H]+ 383.1965. found 383.1964; vmax 823, 1264, 1366, 1500, 1579, 1609, 1674, 2943, 3478 cm−1.
