Hydrochloric Acid → 5-(1,1-Dimethylethyl)-N-methyl-1,3,4-thiadiazol-2-amine

Participants

Reaction Steps

To a solution of 91.6 g of 4-methylthiosemicarbazide and 102.3 g of pivalic acid in 400 ml of dioxane at 90° is added slowly 160.5 g of phosphorus oxychloride at such a rate that the reaction temperature is maintained at 85°-90° C. without external heating. When the addition is complete, the mixture is heated at 85°-90° C until HCl evolution ceases (several hours), is cooled and the supernatant liquid decanted from the solid mass in the flask. The mass is broken up, slurried with 700 ml of water and made basic (pH 8-9) by the slow addition of sodium hydroxide pellets. The resulting precipitate is filtered, washed with water, air dried and recrystallized from hexane to give 119.4 g (80% yield) of 2-tert.butyl-5-methylamino-1,3,4-thiadiazole, m.p. 79°-81°.

Provenance & Evidence