Reaction Steps
Piperidine (0.20 mL, 2.1 mmol) was added to a suspension of 4-benzyloxy-3-methoxybenzaldehyde (0.50 g, 2.1 mmol) and 2-[(carboxyacetyl)amino]benzoic acid (0.42 g, 1.9 mmol) in toluene (5 mL) and treated according to Procedure 2, acidifying with 20% AcOH. The crude product was recrystallised from EtOH providing (E)-2-[[3-(4-benzyloxy-3-methoxyphenyl)-1-oxo-2-propenyl]amino]benzoic (0.48 g, 63%) as a yellow crystalline solid; mp 197-199° C.; δH (400 MHz, DMSO-d6) 3.84 (s, 3H, OCH3), 5.13 (s, 2H, OCH2), 6.79 (d, J=15.6 Hz, 1H, CH═CHCO), 7.07 (d, J5′,6′=8.0 Hz, 1H, H5′), 7.16 (t, J3,4=J4,5=8.0 Hz, 1H, H4), 7.22 (d, J5′,6′=8.0 Hz, 1H, H6′), 7.31-7.46 (m, 6H, H2′, Ph), 7.55 (d, J=15.6 Hz, 1H, CH═CHCO), 7.61 (t, J4,5=J5,6=8.0 Hz, 1H, H5), 8.00 (d, J3,4=8.0 Hz, 1H, H3), 8.62 (d, J5,6=8.0 Hz, 1H, H6), 11.28 (s, 1H, NH), 13.60 (br s, 1H, CO2H); do (100 MHz, DMSO-d6) 55.7, 69.8, 110.7, 113.1, 116.6, 120.0, 120.3, 122.5, 122.7, 127.5, 127.8, 127.9, 128.4, 131.1, 134.0, 136.8, 141.1, 141.6, 149.3, 149.6, 164.2, 169.5; HRMS (ESI) calculated for C24H21NO5 [M−H]− 402.1336. found 402.1342; vmax 697, 1133, 1233, 1516, 1599, 1673, 1697, 3035 cm−1.
