反应详情

Piperidine (0.50 mL, 5.1 mmol) was added to a suspension of 4-hydroxy-3-methoxybenzaldehyde (0.77 g, 5.1 mmol) and 2-[(carboxyacetyl)amino]benzoic acid (1.0 g, 4.5 mmol) in toluene (5.0 mL) and treated according to Procedure 2, acidifying with 1 M HCl. (E)-2-[[3-(4-Hydroxy-3-methoxyphenyl)-1-oxo-2-propenyl]amino]benzoic acid (1.1 g, 78%) was obtained as a yellow crystalline solid; mp 207.5-208.5° C., lit. [25] 230-233° C.; δH (500 MHz, DMSO-d6) 3.83 (s, 3H, OCH3), 6.71 (d, J=15.5 Hz, 1H, CH═CHCO), 6.80 (d, J5′,6′=8.5 Hz, 1H, H5′), 7.13 (dd, J5′,6′=8.5, J2′,6′=1.5 Hz, 1H, H6′), 7.15 (t, J3,4=J4,5=8.0 Hz, 1H, H4), 7.34 (d, J2′,6′=1.5 Hz, 1H, H2′), 7.52 (d, J=15.5 Hz, 1H, CH═CHCO), 7.60 (td, J4,5=J5,6=8.0, J3,5=2.0 Hz, 1H, H5), 8.00 (dd, J3,4=8.0, J3,5=2.0 Hz, 1H, H3), 8.62 (d, J5,6=8.0 Hz, 1H, H6), 9.57 (s, 1H, OH), 11.27 (s, 1H, NH), 13.61 (br s, 1H, CO2H).

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