Acetic Acid → HCID 21466966, compound

Participants

Reaction Steps

Concentrated hydrochloric acid is added to a mixture of 4-cyano-3,4-dihydro-6-methoxy-2H-1-benzopyran-4-malononitrile (42.76 g, 0.1688 mol) in acetic acid at 30° C. The reaction mixture is heated at reflux for three days, cooled and concentrated in vacuo to give a brown solid. The solid is stirred in an ether/water mixture, filtered, washed sequentially with ether and water and dried to obtain 4-carboxy-3,4-dihydro-6-hydroxy-2H-1-benzopyran-4-acetic acid as a gray solid (10.25 g) which is identified by 1H and 13CNMR spectral analyses.

Provenance & Evidence