Hydrochloric Acid → HCID 70389796, compound

Participants

Reaction Steps

A mixture of 5.3 g of 5-ethoxycarbonylamino-5,6-dihydro-4H-thieno[2,3-b]thiopyran, 20 ml of 26% aqueous sodium hydroxide and 20 ml of 1,2-propanediol is heated at 140° for 3 hours. The reaction mixture is cooled and carefully acidified with 29 ml of 6N hydrochloric acid leading to evolution of gas. The resulting mixture is basified with 50% sodium hydroxide solution and extracted with ethyl acetate. The ethyl acetate extract is evaporated to dryness, the residue is dissolved in ether, the ether solution is washed with water and evaporated to dryness. The residue is dissolved in 40 ml of ethyl acetate and 41 ml of a solution of hydrogen chloride in ethyl acetate (0.535 molar) is added. The resulting precipitate is collected and dried to yield 5,6-dihydro-4H-thieno[2,3-b]thiopyran-5-amine hydrochloride.

Provenance & Evidence