Ethyl 8-chloro-4,5-dihydro-5-methyl-4-oxopyrano[3,2-b]indole-2-carboxylate → HCID 12628430, compound

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Reaction Steps

A mixture of 3.5 g (0.012 mole) of ethyl 8-chloro-4,5-dihydro-5-methyl-4-oxopyrano[3,2-b]indole-2-carboxylate in 50 ml glacial acetic acid and 10 ml conc. hydrochloric acid was stirred at reflux for 3 hr, then cooled and added to 500 g ice - H2O. The crude product was filtered, washed with 50% aqueous ethanol, and air dried. A suspension of the product in 75 ml of chloroform was stirred for 90 min at room temperature, then filtered. After recrystallization twice from DMF-water, the final product was dried for several hours under high vacuum at 100°. The yellow flakes obtained had a mpt. of 290°-dec.

Provenance & Evidence