Sulfuric Acid → HCID 20253651, compound

Participants

Reaction Steps

To a stirred mixture containing 6.9 g of 5-(3-aminophenyl)-1,6-naphthyridin-2(1H)-one dihydrochloride monohydrate and 50 ml of water in an ice bath was slowly added 50 ml of concentrated sulfuric acid followed by 1.45 g of sodium nitrite. The reaction mixture was stirred in an ice bath for about 2 hours and then allowed to warm up to room temperature. It was next heated on a steam bath for about 2 hours and then allowed to stand at room temperature overnight. The reaction mixture was treated with ammonium hydroxide solution until it became weakly basic. The separated solid was collected, washed with water and dried in a vacuum oven at 90° C. The solid was recrystallized from boiling isopropyl alcohol using decolorizing charcoal, the mixture filtered and the filtrate concentrated until the solid separated. The solid was collected and washed with isopropyl alcohol. Additional solid was obtained by concentrating the filtrate. The solids were combined and recrystallized from dimethylformamide using decolorizing charcoal and dried in a vacuum oven at 90° C. to yield 1.3 g of 5-(3-hydroxyphenyl)-1,6-naphthyridin-2(1H)-one, m.p. 297°-299° C. with decomposition.

Provenance & Evidence