Carbon Dioxide → Ethyl 3-(4-methoxyphenyl)-[1,2,4]thiadiazole-5-carboxylate

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Reaction Steps

Ethyl cyanoformate (16.9 g, 0.171 mol) is added to a stirred solution of 5-(4-methoxyphenyl)-[1,3,4]oxathiazolin-2-one (11.9 g, 0.057 mol) in p-xylene (100 ml). The mixture is heated to 115°-132° C. for 10 hours, during which time carbon dioxide is liberated. The solvent is evaporated in vacuo and the residue is triturated with di-isopropyl ether. The crystalline solid is filtered off, washed with a small amount of diisopropyl ether and dried, to give ethyl 3-(4-methoxyphenyl)-[1,2,4]thiadiazole-5-carboxylate (11.6 g, 77%) as beige crystals, m.p. 61°-63° C.

Provenance & Evidence