Benzothiazole-2-thiol

Conceptually closely related, cefroxadi ne (40) can be prepared by several routes, including one in which the enol (33) is imethylated with diazomethane as a key step. A rather more involved route starts with comparatively readily available phenoxymethylpenicillin sulfoxide benzhydryl ester (36). This undergoes fragmentation when treated with benzothiazole-2-thiol to give Ozonolysis (reductive work-up) cleaves the... 

Along with the testing of the materials of interest, control experiments with reference substances need to be performed. At least every 6 month, the control test needs to be carried out using mild-to-moderate skin sensitizers [recommended substances are a-hexylcinnamaldehyde, benzothiazole-2-thiol (mercaptobenzothiazole), and benzocaine] to evaluate the testing procedure. 

The formation of benzothiazole-2-thiol (386) from aniline (385), carbon disulfide, and sulfur af 230 °C has been shown fo occur by a sequence of fhree principal steps. Labelling experiments confirmed fhaf bofh sulfur afoms originafed from carbon disulfide. An initial polar reaction to form thiocarbanilide (389) via phenylcarbamic acid... 

Benzoquinone, 3,5-di-t-butyl-cobalt complexes, 398 Bcnzoselenophene, 2-(2-pyridyl)-metal complexes, 807 Benzothiazole-2-thiol metal complexes, 802 Benzotriazoles metal complexes, 78 P a, 77... 

Reaction of [RuCl2(diene)] (diene = nbd, 1,5-cod) with 2( 1 //)-pyridinethione (pyridine-2-thiol), 2(l//)-pyrimidinethione or benzothiazole-2-thiol (2-mercaptobenzothiazole) (HL) in hot DMF in... 

Abbreviations used pop, dianion of pyrophosphite (P20,.iH2 ) pep, dianion of /u.-methylenebis(phosphite) im, anion of imidazole 4-mpyt, anion of 4-methylpyridine-2-thioI pyt, anion of pyridine-2-thiol pyms, anion of pyrimidine-2-thione bttz, anion of l,3-benzothiazole-2-thiol form, anion of di-p-tolylformamidine dpb, N,W -diphenylben-zamidine mhp, anion of 6-methyl-2-hydroxypyridine chp, 6-chloro-2-hydroxypyridine and dpt, 1,3-diphenyltriazen. 

Ligands that provide the dipalladium complexes are dithiocarbox-ylates (RCS2 ), l,3-benzothiazole-2-thiol (bttzH), 1,3-diphenyltriazen (dptH), -di-p-tolylformamidinate (form), N AT-diphenylbenzami-... 

CI2 gas was bubbled at 0°C into 33% AcOH in HjO (60 mL). After a yellow precipitate formed, a suspension of l,3-benzothiazole-2-thiol (10.0 g, 60 mmol) in 33% AcOH in HjO (60 mL) was added in ca. 20 portions over 2 h still with Cb bubbling through the mixture (internal temperature was maintained at 0 °C). A large excess of Clj is essential. The yellow suspension was stirred at 0 °C for further 15 min. The mixture was filtered through a cooled filter, the solid was washed with ice water (100 mL) and dissolved in CH2CI2 (100 mL), and the clear soln was washed with NaHC03 (100 mL), and cold brine. The organic phase was dried (powdered molecular sieves 4 A) at 0 °C over 1 h, and filtered. The soln was concentrated and dissolved in EtjO (20 mL), cooled to —78°C, filtered and washed with EtjO (10 mL) yield 9.6-10.0 g (69-72%) white needles mp 105-108 °C (dec). Freshly prepared l,3-benzothiazole-2-sulfonyl chloride is stable at rt for several hours, a smell of SO2 indicates decomposition after several days. 

Primary allylic sulfides of derivatives of benzothiazole-2-thiol react with Grignard reagents in the presence of copper(I) iodide to yield olefins, with or without allylic rearrangement, depending on the nature of the solvent and the allylic sulfide [71 Eq. (62) and Table 14]. 

Bis(benzothiazol-2-yl) disulfide 579,580 A solution of benzothiazole-2-thiol in the calculated amount of dilute sodium hydroxide solution is treated with the calculated amount of aqueous potassium hexacyanoferrate(m) solution. The precipitated disulfide is collected, washed with water, and recrystallized from benzene, the m.p. then being 186°. 

A solution of benzothiazole-2-thiol (8.4 parts) in dilute (40 g per 1) sodium hydroxide solution (150 parts) is submitted to the action of hydrogen peroxide (6 parts) in concentrated aqueous solution the sulfonic acid formed can be salted out by sodium chloride. 

Bromobenzothiazole can be obtained from the reaction of benzothiazole-2-thiol with bromine but in general, hetero-ring halides are prepared from the corresponding oxygen-substituted heterocycle by treatment with thionyl chloride or phosphoryl chloride. ... 

Bromo nitrostyrene bis(trichloromethyl) sulphone N-alkyl dimethylbenzyl ammonium chloride Benzothiazole-2-thiol... 

Synonyms 2-benzothiazolethiol 2-mercaptobenzothiazole captax Rotax 2-benzathiazalethiol Dermacid MBT mercaptobenzothia-zole Mertax Nocceler M Thiotax 2(3H)-benzothiazolethione Pennac MBT Rokon sulfadene benzothiazolethiol benzothiazole-2-thiol... 

Preparative Methods 2-allyloxybenzothiazoles are prepared by reaction of potassium allyloxides with 2-chlorobenzothiazole in dry ether at rt. 2-Allylthiobenzothiazoles are prepared by reaction of allylic alcohols with 2,2 -dithiobis(benzothiazole) and triphenylphosphine or with benzothiazole-2-thiol, diethyl azodicarboxylate, and triphenylphosphine in dry toluene at rt. ... 

Related Reagents. Benzothiazole-2-thiol 1-Phenyl-1/Atetra-zolyl-5-thiol Pyridine-2-thiol. 

In 2009, Patel and co-workers developed two ligand-assisted Cu(i)-cata-lyzed sequential intra- and intermolecular S-arylations for the synthesis of arylthiobenzothiazoles in a one-pot manner without an inert atmosphere (Scheme 2.140). Low catalyst loading, inexpensive metal catalyst and ligand, lower reaction temperature, and shorter reaction times make this method superior to all reported methods for the synthesis of aiylthio-benzothiazole. In detail, the reaction started with an intramolecular S-aiy-lation of a dithiocarbamate salt and yielded benzothiazol-2-thiol or MBT (2-mercaptobenzothiazole), which was then followed by an intermolecular C-S coupling giving 2-atylthiobenzothiazoles directly. In the communication, the authors found the following order of reactivity in aryl iodides P-NO2 > 0-NO2 > o-COOMe > m-Cl > H > p-Me > p-OMe. 

Oxidation and Reduction.— The electrochemical oxidation of benzothiazole-2-thiol to its disulphide has been further studied. This conversion may be accomplished with ozone in the presence of potassium iodide to prevent ozoniza-tion. > Desulphurization of benzothiazoles as a preparative procedure does not appear to have been exploited to the extent that it has in the field of thiophen chemistry. Noteworthy, however, is the desulphurization of sugars (17 e.g., n = 3, R = H) to l-deoxy-l-(iV-methylanilino)-alditals. ... 

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