2-Thiophenecarbonyl chloride → HCID 12747881, compound

Participants

Reaction Steps

To a well stirred mixture of 6,7-dichloro-2,3-dihydrobenzofuran-2-carboxylic acid (2.6 g.) and thiophene-2-carbonyl chloride (4 ml.) protected from the atmosphere with a calcium chloride tube is added anhydrous aluminum chloride (6.0 g.) over a one-hour period. The reaction mixture is heated at 80°-90° C. for 31/2 hours then poured into ice water (100 ml.) and hydrochloric acid (10 ml.). The product is extracted into ether, washed with water, then extracted into aqueous sodium bicarbonate (100 ml.) from which the sodium salt of the product precipitates. The sodium salt of the product is placed in a separatory funnel with dilute hydrochloric acid (100 ml.) and ether (100 ml.) and shaken until the solid dissolves. The ether solution is washed with water, brine, dried over magnesium sulfate and the ether distilled at reduced pressure. The (±)6,7-dichloro-2,3-dihydro-5-(2-thenoyl)benzofuran-2-carboxylic acid melts at 187° C. after crystallization from butyl chloride.

Provenance & Evidence