Water → HCID 19036596, compound

Participants

Reaction Steps

A mixture of 2.5 g of N-[2-(1,4-dihydro[1]benzopyrano[4,3-b]pyrrol-1-yl)-ethyl]-acetamide, 3.28 g of potassium hydroxide, 20 ml of water and 40 ml of ethylene glycol was heated to 110° while stirring for 23 hours. After cooling, the reaction mixture was poured into 100 ml of saturated sodium chloride solution and extracted three times with 200 ml of ethyl acetate each time. The organic phases were washed once with 200 ml of saturated sodium chloride solution, dried over magnesium sulfate and concentrated in a vacuum. The residue was purified by column chromatography on silica gel (dichloromethane/methanol/ammonia 200:10:1). The oil obtained was dissolved in 110 ml of anhydrous diethyl ether, filtered and treated with a solution of 436 mg of fumaric acid in 20 ml of anhydrous methanol. The mixture was stirred at room temperature for 18 hours and the white crystals were subsequently filtered off under suction. 812 mg (31%) of 2-(1,4-dihydro-[1]benzopyrano[4,3-b]pyrrol-1-yl)-ethylamine fumarate (1:0.5) with m.p. 180° were obtained.

Provenance & Evidence