The field of this invention, in general, is that of improved methods for preparing well-known organic intermediates which are used in the preparation of end products having a variety of useful properties. In view of the fact that many chemical reactions for the preparation of useful end-product compounds proceed through the formation of intermediates, it, therefore, becomes important to develop increasingly efficient methods for the synthesis of such intermediates.
More particularly, this invention relates to the novel preparation in high yield of the compound 5-t-butyl-2-methylamino-1,3,4-thiadiazole, one use of which is to prepare the broad spectrum herbicide N-[5-(1,1-dimethylethyl)-1,3,4-thiadiazol-2-yl]-N,N'-dimethylurea, known in commerce under the common name Tebuthiuron. U.S. Pat. No. 3,803,164 discloses the preparation of certain herbicidally active compounds, the 1-(5-alkylthiadiazol-2-yl)-1,3-dialkylureas, of which Tebuthiuron is a member, by the reaction of a 2-alkylamino-5-alkyl-1,3,4-thiadiazole with an isocyanate of the formula R--N.dbd.C.dbd.O where R is hydrogen or C.sub.1 -C.sub.4 alkyl.
The compound 5-t-butyl-2-methylamino-1,3,4-thiadiazole can also be utilized as the starting material in a wide variety of reactions to provide useful end products, such as, for example, in the reaction with isocyanates to form ureas, with isothiocyanates to form thioureas, with organic acids and acid chlorides to form amides, with alkyl and aryl chloroformates to form carbamates, and with alkyl chlorides to form alkylated amines.
USPTO Backgrounds
USPTO Backgrounds