Diethyl Oxalate → dibenzo[b,f]thiepin-10(11H)-one

Participants

Reaction Steps

Stir at room temperature a mixture of 5.118 gm. of the amide of Step 5, 2.939 gm. of diethyloxalate, 4.723 gm. of potassium t-butoxide and 40 ml. of dimethylformamide for 6 hours. Pour the reaction mixture into 300 ml. of ice-water and extract with 300 ml. of ethyl acetate. Acidify with 6N hydrochloric acid and separate the ethyl acetate layer. Wash with saturated sodium chloride solution and dry. Evaporate to dryness and dissolve the residue in warm dioxane. Treat with a slight excess of ammonia and separate the solid by filtration. Wash with dioxane and dry. Suspend the product in water, acidify with 6N hydrochloric acid and extract with ethyl acetate. Wash the extract with saturated sodium chloride solution, dry over magnesium sulfate and evaporate to obtain the title product.

Provenance & Evidence