2-Phenylaminomethylene-malonic aciddiethyl ester

62-53-3

87-13-8

54535-22-7

Aniline (2.733 mL, 29.99 mmol) was mixed with diethyl ethoxymethylenemalonate (6.063 mL, 30.00 mmol) and the reaction was stirred at 120-130 °C for 16.5 hours. The progress of the reaction was monitored by thin-layer chromatography (TLC, unfolding agent was ethyl acetate:cyclohexane=1:1) to confirm that the reaction was complete (disappearance of the raw material point and appearance of a new UV-active point with an Rf value of 0.84). Upon completion of the reaction, the reaction solution was cooled to room temperature to afford the intermediate diethyl 2-phenylaminomethylene-malonate (35) as a dark yellow crystalline solid (7.899 g, quantitative yield). The melting point of the compound was 36-37 °C. High-resolution mass spectrometry (HRMS-EI) analysis showed that the measured value of [M]+ was 263.11531, which was consistent with the theoretical value of C14H17NO4 (263.11521). IR spectra (thin-film method, cm-1): 3265, 3184 (weak, NH stretching vibration), 3050 (weak, aryl ring C-H stretching vibration), 2981, 2936, 2904, 2871 (medium-strong, alkyl C-H stretching vibration), 1717 (strong, intramolecular hydrogen bonding C=O conjugated to C=C), 1691 (strong, C=C-NH), 1655 ( strong, C=N-), 1623 (strong, aryl ring conjugation C=C), 1255 (strong, C-N stretching vibration). NMR hydrogen spectrum (500 MHz, CD3CN): δ 1.31 (3H, triple peak, J=7.1 Hz, CH3), 1.32 (3H, triple peak, J=7.2 Hz, CH3), 4.19 (2H, quadruple peak, J=7.2 Hz, CH2), 4.25 (2H, quadruple peak, J=7.1 Hz, CH2), 7.16 (1H triple peak, J=7.4 Hz, para-ArH), 7.20 (2H, double triple peak, J=7.6 Hz, ortho-ArH), 7.38 (2H, multiple peaks, J=7.4 Hz, meta-ArH), 8.48 (1H, double peak, J=13.8 Hz, CH-NH), 10.81 (1H, double peak, J=13.6 Hz, CH-NH). NMR carbon spectrum (125 MHz, CD3CN): δ 14.1, 14.2 (2×CH3), 60.3, 60.6 (2×CH2), 93.9 (O=CCC=O), 117.6 (2×ortho-ArC), 125.1 (para-ArC), 130.1 (2×meta-ArC), 139.8 ( ArCquat-NH), 151.9 (NH-CH), 165.6 (C=O), 168.8 (hydrogen-bonded C=O).