HCID 12620579, compound → 5-Methyl-4-oxo-4,5-dihydropyrano[3,2-b]indole-2-carboxylic acid

Participants

Reaction Steps

A mixture of 5.40 g (0.020 mole) of ethyl 4,5-dihydro-5-methyl-4-oxopyrano [3,2-b]indole-2-carboxylate in 80 ml of 1% aqueous sodium hydroxide was stirred at room temperature for 30 min. The nearly one-phase mixture was extracted twice with 50 ml CH2Cl2 and the aqueous layer was cooled in ice and acidified with 4 N HCl. The gelatinous yellow crude product was filtered, digested for a few minutes on a steam bath with 100 ml hot water and then re-filtered. Recrystallization from ab. EtOH gave yellow needles of mpt. 280°-dec.

Provenance & Evidence