Thieno thiazoles, synthesis

Thieno[2,3 -h]selenophenes lithiation, 4, 950 Thienospirans synthesis, 4, 760 Thieno[3,4-c][l,2,5]thiadiazoles cycloaddition reactions, 6, 534 reactions, 6, 1036 synthesis, 6, 1042, 1044 Thieno[2,3-d]thiazole, 2-acylamino-synthesis, 6, 1010 Thieno[2,3-d]thiazoles synthesis, 5, 116 6, 988, 994 Thieno[3,2-d]thiazoles synthesis, 5, 135 6, 1015 Thieno[3,4-d]thiazolidine-2-thione, perhydro-... 

Thiazolo] 2,3fl) indole, in synthesis of chain-bridged thiazolocyanines, 58 Thiazolosemicyanines, tables of, 119 Thiazolostyryl dyes, tables of, 107 Thieno [ 2,3d ] thiazole. 30 2-[2-Thienyl) selenazole, formylation in 5-position, 239... 

More recently, this approach was used in the synthesis of 3-(thiazol-2-yl)thieno [3,2-Z>]pyridines 137 from the corresponding ethylenedithiolates 138 (2003MI2). 

The synthesis of some new substituted thieno[2,3-Z>]thiophenes (369)-(372) has been achieved <93BCJ201l> in a one-pot reaction employing solid-liquid phase transfer catalysis (PTC) conditions (K2C03, benzene, tetrabutylammonium bromide catalyst) and starting from acetylacetone, CS2, and a-chloro compounds in 1 1 2 molar ratio. The reaction of acetylacetone and CS2 with ethyl chloroacetate, chloroacetonitrile, 2-(chloroacetylamino)thiazole, or chloroacetanilide was carried out under PTC conditions by stirring the reactants reaction times and temperatures were optimized. The corresponding thieno[2,3-6]thiophenes (369)-(372) were obtained in excellent yields (51-93%). 

Thiation is used predominantly for the synthesis of annelated thiazoles (e.g., (109)—(111)) from heterocyclic acylamides bearing either adjacent phenol or halogen substituents (Equations (33)— (35)) (70KGS1624, 77KGS1495, 87KGS410). The thieno[3,2-c]isothiazolium perchlorate (113) was obtained from the 2-benzoyl-3-(phenylamino)thiophene (112) by sequential reaction with phosphorus pentasulfide and perchloric acid (Equation (36)) <77CJC1123>. 

Other one-carbon closures include the synthesis of the thieno[2,3-d]thiazoles (125) from the thiolamine (124) and orthoesters (Equation (40)) <88JPR866> and the thermal cyclization of the isothiocyanate (126) to the 2-acylthieno[2,3- /]thiazoles (127) (Equation (41)) <74KGS1204>. 

A synthesis of 2-thiolthieno[2,3-.. These dithiazolium salts (297) are obtained from the reaction of thienylcarboxylic acids with sulfur monochloride. Treatment of the dithiazolium hydroxide (297b) with carbon disulfide affords the thiol (298) (Scheme 55). 

Synthesis of 3-substituted 6-arylbenzo[r/][l,2,3]triazin-4(3/f)-ones using polymer bound triazenes has been reported <04JCO38>. Gas-phase thermolysis of thieno[3,2-e][l,2,4]triazines yielded benzonitrile, isothiazole, pyrimidine, [ 1 benzothieno[2,3-dJpyrimidine and thieno[3,2-rf thiazole derivatives. These products were separated by HPLC and column chromatography and characterized using GCMS, LCMS, H, C-NMR and 2D NMR spectroscopy... 

Monocyclic and Bicyclic aromatic heterocycles such as imidazoles, thiazoles, thiadiazoles, oxazoles, oxadiazoles quinazolines, indoles, benzimidazoles, purines pyrido[43-d]pyri-midines, thiazolo[5,4-d]pyrimidines, thiazolo[4,5-d]pyrimidines, oxazolo[5,4-d]pyrimi-dines and thieno[2,3-d]pyrimidines are renowned pharmacophores in drug discovery. These special structures are well explained and exemplified in chemical compound libraries. In this chapter, several types of thiazole based heterocyclic scaffolds such as mono-cyclic or bicyclic systems synthesis and their biological activities studies are presented, which are not frequently present in books and reviews. We mention the first importance of synthetic route of various thiazole based compounds and their applications in medicinal chemistry in this chapter. 

Thienothiazoles and Selenolothiazoles.— An unusual synthesis (Scheme 13) of a thieno[2,3-c ]thiazole (159) has been reported, the key steps of which are the formation of a dithiazolium salt (158), its hydrolysis, and the insertion of a carbon disulphide moiety, with extrusion of sulphur to form the thiazole ring. ... 

Paulmier and coworkers, starting from ortho-nltro-substituted thienyl- and selenienylthiocyanates and selenocyanates, have worked out convenient methods for the synthesis of thieno[2,3-d]thiazole and selenolo[2,3-d]thiazoles. From the same starting materials, thieno[2,3-elthiazines were also prepared. The same group also... 

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