Sulfuric Acid → Methyl 4-(4-oxo-chroman-3-ylidenemethyl)-benzoate

Participants

Reaction Steps

Concentrated H2SO4 (2 ml) was slowly added to a solution of 4-chromanone (2.00 g, 13.50 mmol) and methyl-4-formylbenzoate (2.11 g, 12.86 mmol) in glacial acetic acid. The reaction mixture was stirred 16 h at room temperature. The solvent was concentrated to half volume the resulting precipitate was filtered and rinsed with ethyl acetate to afford the title compound 260 (3.11 g, 82%) as a purple solid. 1H NMR: (DMSO) δ (ppm): 8.05 (d, J=8.2 Hz, 2H), 7.90 (d, J=7.6 Hz, 1H), 7.79 (s, 1H), 7.64-7.59 (m, 3H), 7.15 (dd, J=7.6, 7.6 Hz, 1H), 7.07 (d, J=8.2 Hz, 1H), 5.43 (s, 2H), 3.89 (s, 3H).

Provenance & Evidence