Sulfuric Acid → 4-(3-(2-Chlorobenzoyl)-5-ethylthiophen-2-yl)-3-hydroxymethyl-5-methyl[1,2,4]triazole

Participants

Reaction Conditions

Reaction Steps

4-(2-Chlorophenyl)-2-ethyl-9-methyl-6H-thieno[3,2-f] [1,2,4]triazolo[4,3-a] [1,4]diazepine (34.3 g) was added to water (500 ml), and conc. sulfuric acid (74 ml) was dropwise added with vigorous stirring. The mixture was further stirred at 90° C. for 1 hour, and sodium nitrite (74 g) was added. Then, potassium carbonate was added to the reaction mixture to make the mixture alkaline. The mixture was extracted with ethyl acetate and washed with water. The mixture was dried over magnesium sulfate. The solvent was evaporated, and the residue was recrystallized from ethyl acetate-diisopropyl ether to give 26.06 g of 4-(3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl)-3-hydroxymethyl-5-methyl[1,2,4]triazole.

Provenance & Evidence