Hydrochloric Acid → HCID 70594922, compound

Participants

Reaction Conditions

Reaction Steps

To a well stirred mixture of ethyl 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylate (5.2 g) and 2-thienylsulfonyl chloride (3.6 g) protected from the atmosphere with a calcium chloride tube is added the anhydrous aluminum chloride (2.6 g) over a five minute period. The reaction mixture is stirred at 25° C. for 18 hours and at 90° C. for one hour, then poured into ice water (150 ml) and hydrochloric acid (15 ml). The esterified product is extracted into ether, washed with brine, dried over magnesium sulfate and the ether distilled at reduced pressure. The residue is warmed (80° C.) in 10% NaOH (100 ml) for one hour to obtain a solution which is acidified with hydrochloric acid (25 ml) to obtain the product as a viscous oil. The product is extracted into ether, washed with brine, dried over magnesium sulfate and the ether distilled at reduced pressure. The 6,7-dichloro-2,3-dihydro-5-(2-thienylsulfonylbenzofuran-2-carboxylic acid hemihydrate melts at 189°-193° C. after purification by column chromatography.

Provenance & Evidence