Water → HCID 18917609, compound

Participants

Reaction Conditions

Reaction Steps

2-Ethyl-4-(4-hydroxyphenyl)-9-undecyl-6H-thieno[3,2-f][1,2,4]triazolo[4,3-a][1,4]diazepine (20 g) obtained in Example 17 was dissolved in dioxane (300 ml). Thereto were added water (300 ml) and sulfuric acid (12 ml) and the mixture was stirred at 80° C. for 2 hours. Thereto was gradually added dropwise a solution of sodium nitrite (30 g) in water (100 ml) and the mixture was stirred at 80° C. for 3 hours. After cooling, potassium carbonate was added thereto to make the reaction mixture alkaline. The mixture was extracted with ethyl acetate, washed with water and dried over anhydrous magnesium sulfate. After filtration, the filtrate was concentrated under reduced pressure and purified by silica gel column chromatography to give 11 g of 5-ethyl-3-(4-hydroxybenzoyl)-2-(3-hydroxymethyl-5-undecyl-1,2,4-triazol-4-yl)thiophene as an oily substance.

Provenance & Evidence