Methanol → 2-Methyl-3-sulfanyl-1,2-dihydro-1,2,4-triazine-5,6-dione

Participants

Reaction Conditions

Reaction Steps

Under anhydrous condition, 35 g of diethyloxalate is added, dropwise, to a vigorously stirred solution of 21 g of 2-methyl-3-thiosemicarbazide, 32.4 g of fresh sodium methoxide, and 750 ml of methyl alcohol. The resulting suspension is heated at 60° C. for 4 hours, stirred overnight at room temperature, and heated at 70° C. for 15 hours. The white suspension is cooled to room temperature, 200 ml of ice water is added and the reaction concentrated in vacuo. The residue is cooled to 0° C. and made acidic with 2N hydrochloric acid. The reaction mixture is concentrated, ethyl alcohol is added and the suspension is heated to boiling. The white precipitate is collected, washed with hexane and dried to give 11 g of the crude product. Eight grams of the crude product is heated in methylene chloride and filtered while hot. The collected solid is resuspended in methyl alcohol and a solution of 4N potassium-2-ethyl hexanoate is added. The mixture is cooled to 0° C. and the precipitate collected. The solid is dissolved in water, filtered, and 2N hydrochloric acid is added to the clear 0° C. solution. The resulting precipitate is collected and dried to give 4.1 g of the pure product.

Provenance & Evidence