Potassium Iodide → HCID 19853504, compound

Participants

Reaction Steps

To a solution of 6.2 g of 85% potassium hydroxide in 18 ml of water is added a solution of 6 g (0.03 mol) of 2-mercapto-5-pyrazin-2-yl-1,3,4-thiadiazole in 90 ml of dioxane. Then 0.2 g of potassium iodide and 0.2 g of tetrabutylammonium bromide are added to the reaction mixture and 13 g of gaseous difluoromethane are introduced over 6 hours at 22° to 37° C. After evaporating off the dioxane, the reaction mixture is diluted with ethyl acetate, the aqueous phase is separated and the organic solution is washed cold with 1N sodium hydroxide solution and water, dried over sodium sulfate and clarified with activated carbon. The ethyl acetate is removed under vacuum and the residue is crystallised from ethyl acetate/hexane, affording 312 g (43%) of the title compound with a melting point of 113°-115° C.

Provenance & Evidence