Ethanol → HCID 19979494, compound

Participants

Reaction Steps

A mixture of 4-(5-methyl-1,2,4-oxadiazol-3-ylmethyl)-7-nitro-2H-1,4-benzoxazin-3(4H)-one (3.2 g) and ethanol (40 ml) was prepared. To this mixture was added a solution of stannous chloride dihydrate (11.3 g) in concentrated hydrochloric acid (44 ml) at a temperature of 10° to 20° C. The reaction mixture was stirred at a temperature of 60° to 70° C., and distilled to dryness under a reduced pressure. The resulting residue was admixed with ice (150 g). To the mixture thus obtained was added dropwise a 25% aqueous potassium hydroxide solution at a temperature of 0° to 10° C. to render the mixture alkaline. The resultant alkaline solution was extracted with dichloromethane (80 ml×2). The dichloromethane layer was washed with water, and dried over anhydrous sodium sulfate. The dichloromethane solvent was distilled off under a reduced pressure, and the resultant solid residue (1.3 g) was recrystallized from toluene, so that the aimed compound, i.e. 7-amino-4-(5-methyl-1,2,4-oxadiazol-3-ylmethyl)-2H-1,4-benzoxazin-3(4H)-one (1.1 g) was obtained. m.p. 146°-147.5° C.

Provenance & Evidence