4-Hydroxybenzaldehyde → Diethyl 2-(4-hydroxybenzylidene)malonate

Participants

Reaction Conditions

Reaction Steps

To a 100 mL RB flask fitted with magnetic stirrer was charged with piperidine (0.426 g, 0.5 mL, 5 mmol) and acetic acid (0.3 g, 0.3 mL, 5 mmol). To this, toluene (25 mL) was added, followed by 4-hydroxybenzaldehyde (2 g, 16.4 mmol) and diethyl malonate (3.15 g, 19.7 mmol). The RM was heated at 125° C., by fitted with a dean-stark's apparatus for 5 h. After 5 h, the RM was concentrated; water (50 mL) was added and extracted with ethyl acetate (50 mL×2)). The organic layer was washed with saturated brine solution (50 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The product was obtained as yellow solid. (2 g, yield: 46.2%); MS (ESI, 120 eV): m/z=263.1 (M−H)+; 1H NMR (300 MHz, DMSO-d6): δ 10.27 (s, 1H), 7.58 (s, 1H), 7.36-7.38 (d, 2H), 6.81-6.84 (d, 2H), 4.17-4.32 (m, 4H), 4.06-4.14 (q, 1H), 1.21-1.26 (t, 6H).

Provenance & Evidence