trans-Crotonyl chloride → HCID 53812349, compound

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of ethyl 6,7-dichloro-2,3-dihydro-2-benzofurancarboxylate (13.4 g, 0.05 mole) and crotonyl chloride (8.15 g, 0.09 mole) in CH2Cl2 (30 ml) cooled to 5° C. in an ice bath is added aluminum chloride (22.5 g, 0.17 mole) over a 10 minute period. The reaction mixture is stirred for 1 hour at 25° C. then for 20 minutes at reflux. The reaction mixture is poured into ice water, extracted into ether, washed with water and the ether evaporated in vacuo. The residue is treated with 10 N sodium hydroxide (100 ml) and the resultant sodium salt filtered and suspended in dilute hydrochloric acid which is extracted with ether (206 ml), washed with water, dried over magnesium sulfate, evaporated to 50 ml and treated with hexane to give 6,7-dichloro-2,3-dihydro-5-(1-oxo-2-butenyl)-2-benzofurancarboxylic acid.

Provenance & Evidence