4-(Dimethylamino)cinnamaldehyde

75-07-0

100-10-7

20432-35-3

General procedure for the synthesis of (E)-3-(4-(dimethylamino)phenyl)acrolein from acetaldehyde and p-dimethylaminobenzaldehyde: A mixture of 4-N,N-dimethylaminobenzaldehyde (5.00 g, 34 mmol) with 25 ml of concentrated sulfuric acid was cooled to 0°C. Subsequently, 1 ml of distilled water was slowly added. Keeping the reaction mixture at 0°C, acetaldehyde (5.6 ml, 102 mmol) was added dropwise, ensuring that the reaction temperature did not exceed 2°C. After the dropwise addition, the dark reaction mixture was continued to be stirred at 0°C for 0.5 hours. Subsequently, the reaction mixture was poured into ice water and neutralized with 10% NaOH solution to pH 7. The resulting brown solution was filtered and the crude product was washed with distilled water and crystallized twice by ethanol to give a final orange solid product. The yield was 56% and the melting point was 134-136 °C. The product was analyzed by FT-IR (KBr, cm^-1 ) showing characteristic peaks: 2921, 2801, 2738, 1662, 1599, 1527, 1456, 1373. 1H NMR (300 MHz, CDCl3, ppm) data were as follows: δ 9.62 (1H, d, J=7.5 Hz), 7.48 (2H, d, J=7.5 Hz), 7.41 (1H, d, J=13.1 Hz), 6.71 (2H, d, J=7.5 Hz), 6.57 (1H, dd, J=7.5 Hz, 13.1 Hz), 3.08 (6H, s). Mass spectrometry (MS) analysis showed the molecular ion peak m/z: 176.2 (M+), consistent with the molecular formula C11H13NO.