1.2.5- Thiadiazole synthesis

The Hurd-Mori 1,2,3-thiadiazole synthesis is the reaction of thionyl chloride with the N-acylated or tosylated hydrazone derivatives 1 to provide the 1,2,3-thiadiazole 4 in one simple step. ... 

Sakya, S. M. Hurd-Mori 1,2,3-Thiadiazole Synthesis In Name Reactions in Heterocyclic Chemistry, Eds, Li, J. J. Corey, E. J. Wiley Sons Hoboken, NJ, 2005, 199—206. (Review). 

Tetrydamine, 352 Thalidomide, 296 Thebaine, 318 Theniurn closylate, 99 Theobromine, 456 Theophylline, 464 Thiabendazole, 352, 353 1,2,5-Thiadiazole synthesis,... 

The synthesis of 1,3,4-thiadiazoIes is discussed in terms of the number of bonds being formed and by ring transformation. Thiadiazole synthesis by one-bond formation is exemplified by the cyclization of an acylated thiosemicarbazide as shown in Scheme 16. The most common two bond formation takes place via 1,3-dipolar cycloadditions presented in Scheme 23. 

A unique thiadiazole synthesis from the industrial raw materials sulfur dioxide and potassium cyanide has been reported by Ross and... 

Phenyl-l,3,4-oxathiazol-2-one (370), prepared from primary amides and tri-chloromethanesulfenyl chloride, undergoes a ready thermal elimination of carbon dioxide with the formation of the nitrile sulfide ylide (371). This can be trapped by a wide variety of unsaturated dipolarophiles, and with an alkyne provides a ready route to isothiazoles (372) (see Chapter 4.17). Applications to 1,2,4-thiadiazole synthesis are described in Chapter 4.25. Thermolysis of l,3,4-oxadiazolin-5-ones (500 C/10 mmHg) results in the loss of CO2 and generation of the corresponding nitrilimine (78JOC2037). 

Thiadiazoles, synthesis from carbon disulfide 84S797. 

---