1.2.3.4- Thiatriazole

CN3S s N N N — 5-Phenyl-l,2,3,4-thiatriazole 5-amino-l,2,3,4-thiatriazole 5-phenyl-1,2,3,4-thiatriazole 3-oxide... 

Thiatriazoles readily decompose thermally into nitrogen, sulfur and an organic fragment, usually a cyanide, e.g. (27) Bu OCN + + S (76AHC(20)145). 

Phenylthiazirine (40) can be isolated as an intermediate in the photolysis of 5-phenyl-1,2,3,4-thiatriazole and also from other five-membered ring heterocycles capable of losing stable fragments see Scheme 2 (81AHC(28)231). Photolysis of 5-phenylthiatriazole in the presence of cyclohexene yields cyclohexene episulfide (60CB2353) by trapping the sulfur atom. 

Substituted 1,2,3,4-thiatriazoles (93) are alkylated only under very forcing conditions with triethyloxonium fluoroborate, but then give the expected products (94) (75JOC431). 

There are many related examples which are now known as the general Dimroth rearrangement. For example, 3-ethylamino-l,2-benzisothiazole (419) is in equilibrium in aqueous solution with the 2-ethyl-3-imino isomer (420) <72AHCf 14)43). Dimroth rearrangements are known in the 1,2,4-thiadiazole series (421- 422), and in the 1,3,4-thiadiazole series as products of reactions of halogeno-l,3,4-thiadiazoles see Section 4.02.3.9.1 <68AHC(9)165). For a similar example in the 1,2,3,4-thiatriazole series, see Section 4.02.3.1.9. 

Thiatriazole, 5-arylamino-alkylation, 6, 596 anticancer activity, 6, 598 methylation, 6, 590 reactions... 

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