Water → HCID 178463101, compound

Participants

Reaction Conditions

Reaction Steps

5.0 g (0.017 mol) of 8-methyl-2,3-dihydro-1,1,4,4-tetraoxobenz[1,4]dithiin-7-carboxylic acid were dissolved in 50 ml of acetonitrile, and 1.93 g (0.017 mol) of 1-ethyl-5-hydroxypyrazole and 3.56 g (0.017 mol) of N,N-dicyclohexylcarbodiimide were added. The reaction mixture was stirred at 20° C. for one hour and then taken up in 100 ml of 2% sodium bicarbonate solution, the precipitate that formed was filtered off with suction and the filtrate was dried and concentrated. The remaining white solid (5.8 g) was subsequently dissolved in 15 ml of dioxane, 4.2 g (0.03 mol) of potassium carbonate were added and the mixture was heated under reflux for 3 hours. After cooling, water was added, the mixture was washed with ethyl acetate, the aqueous phase was adjusted to pH 3 using 2N hydrochloric acid and the precipitate was filtered off with suction, washed with water and dried.

Provenance & Evidence