Ethanolamine → 8-(2-hydroxyethylsulfamyl)-3-methyl-4-oxo-2-phenyl-4H-1-benzopyran

Participants

Reaction Steps

A solution of 5 g of Intermediate VIII in 37 ml of tetrahydrofuran was added dropwise at 0° C. to a mixture of 2.5 ml of ethanolamine and 2.5 ml of triethylamine in 25 ml of tetrahydrofuran. After stirring at 20°-25° C., the reaction mixture was poured into 400 ml of water. A precipitate formed, and was collected by suction filtration, washed with water and air dried, yielding 4.6 g of 8-(2-hydroxyethylsulfamyl)-3-methyl-4-oxo-2-phenyl-4H-1-benzopyran, melting at 186°-187° C. after crystallization from ethyl acetate.

Provenance & Evidence