Thionyl Chloride → 6,7-Dihydroxy-4-oxo-4H-1-benzopyran-3-carbonyl chloride

Participants

Reaction Steps

A mixture of 6,7-dihydroxychromone-3-carboxylic acid (9.0 g, 4 mmol) and thionyl chloride (150 ml) was refluxed for 45 minutes and the thionyl chloride was evaporated. After the addition of benzene, the mixture was evaporated again to dryness and the residue was triturated with n-hexane to afford the desired compound (9.1 g, 93.4%).

Provenance & Evidence