Acetyl chloride → 7-Methoxyisochroman-1,3-dione

Participants

Reaction Steps

To a suspension of 2-(carboxymethyl)-5-methoxybenzoic acid (5.22 g) (synthesised using the procedure in Tetrahedron 1975, 31, 2607-19) in acetone (50 ml) was added acetyl chloride (7.06 ml) and the reaction mixture was stirred at room temperature for 18 hours. The solvent was evaporated and azeotroped with toluene (×3). The resultant solid was triturated with diethyl ether to yield 7-methoxy-1H-isochromene-1,3(4H)-dione as a brown solid (4.36 g); NMR Spectrum: (DMSOd6) 3.84 (s, 3H), 4.20 (s, 2H), 7.36 (m, 2H), 7.50 (s, 1H).

Provenance & Evidence