Thiobenzanilide, oxidation

Many of the reagents developed initially for the recovery of base or radioactive metals have also been investigated as potential PGM extractants, e.g., phosphine oxides,310-313 dialkylsulfoxides,314 dialkyl-and diphemd-thioureas,296,315-317 thiopicolinamides, thiobenzanilide,319 phosphate diesters,320 tetra-... 

No aminothiophenones can be obtained by photorearrangement of JV-aryl amides of thiocarboxylic acids. The formation of 2-ethoxybenzthiazole (143) by oxidative photodehydrogenation of 142 is of some interest.11 Similarly, 2-phenylbenzthiazole originates by photocyclization of thiobenzanilide in the presence of oxygen."... 

The first published example of the anodic cyclization with carbon-sulfur bond formation was the oxidation of thiobenzanilide to 2-phenyl-l,3-benzothiazole.120 The oxidation of the thioacetanilides (106) and /V-(3-coumaryl)thioacetamide (108) at a platinum electrode in CH3CN-Et4NC104 gave the expected 1,3-thiazole derivatives 107 and 109 in 60-75% yield169 [Eqs. (81) and (82)]. 

Thiobenzanilide, on anodic oxidation in CH3CN-TEAP at a platinum electrode, yields 2-phenylbenzothiazole other aromatic thiobenzamides react similarly [41]. Analogously, oxidation of A-(2-pyridyl)-thiobenzamide at controlled potential gives 2-phenyl-1,2,4-thiadiazolo[2,3- -] pyridinium perchlorate (XXXI) in 80% yield [41] ... 

In 1886, Jacobson reported the oxidative cyclisation of an aryl thioamide (or thiobenzanilide) to the corresponding 2-phenylbenzothiazole. Since then, the method has gained considerable acceptance and found applications in various syntheses of benzothiazole-containing molecules. 

Oxidation. The rates of formation of 5-oxides of substituted iV (methyl)-thiobenzanilides by oxidation with HjOj in aqueous dioxan have been measured and the effects of substituents were analysed. The results suggest that the thioanilides have the E) configuration (69), and not the (Z)-form (70). Oxidation... 

Trifluoromethylaled thiobenzanilides are converted efficiently to 2-triflnoromelliylbenzothiazoles via intramolecular oxidative cyclization under CAN/NaHCOs oxidation [104]. The optimized reaction conditions were also evaluated for a range of substituted precursors in the presence of 5 mol % PdC [57],... 

In contrast to thioamides, their S-oxides can be methylated with diazomethane. —E A soln. of diazomethane in n-heptane added in one portion to a soln. of thiobenzanilide S-oxide in methanol-chloroform, and the product isolated after 40 min. N-methylthiobenzanilide S-oxide. Y 60%. F. e. s. W. Walter et al., A. 660, 60 (1962). 

Sulphines are formed by the oxidation of thiones with peroxy-acids, but they then react further, albeit much more slowly, to give the ketone, sulphur, and sulphur dioxide. This latter reaction is kinetically similar to many other oxidations with peroxy-acids, and the results are consistent with electrophilic attack of the peroxy-acid on the C=S double bond to give a cyclic sulphinate ester (4), which rapidly decomposes to give the ketone and sulphur monoxide. In contrast, oxidation of thiobenzanilide 5-oxide with m-chloroperoxybenzoic acid gives products derived from the sulphene PhC(NHPh)=SOa. Further examples of the reaction between diarylsulphines and aryldiazomethanes to give epi-sulphoxides have been reported. ... 

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