Mercapto benzimidazol

Nitro-l-isothiocyanato-benzol wird reduktivzu2-Mercapto-benzimidazol-3-oxid cy-clisiert3 ... 

A useful and simple preparation of the thiazolo[3,2-tf]benzoimidazol-3(2//)-one 391 is the reaction of 2-mercapto-benzimidazole 390 with chloroacetyl chloride (Equation 177) <1996MI442>. 

Two approaches have been applied for the synthesis of imidazo[2,l + thia/,ole ring systems. Reaction of 2-mercapto-benzimidazole with perfluoro-2-methylpent-2-ene in the presence of triethylamine gave compound 419 (Equation 192), and cyclocondensation of 2-imidazolidinethione with the alkynyl(phenyl)iodonium salt 420 afforded product 421 (Equation 193) <2001RCB1446, 2003JCM715>. 

Dithiokohlensaure-anilid-S-cstcr kondensieren mit o-Diamino-arenen in Gegcnwart von Quecksilberoxid als Schwefelfanger zu 2-Anilino-benzimidazolen ohne Quecksilberoxid wird 2-Mercapto-benzimidazol erhalten293 294. 

Tab. 14 2-Mercapto-benzimidazole durch Cyclisierung von o-Diamino-arenen mit Kohlen-...

Backerhefe oxidiert 2-Mercapto-benzimidazole zu Bis-[2-benzimidazolyl]-disulfanen380. Auch die Verwen clung von Benzolsulfonylchlorid als Oxidationsmittel ist moglich383. 

Mercapto-benzimidazol (und ahnliche ambidente Nukleophile) werden mit Kohlensaure-al-lylestern thermodynamisch kontrolliert am S-Atom angegriffen, wenn man das thiophile Palladium ) als Katalysator einsetzt. Mit 3-Ethoxycarbonyloxy-l-phenyl-propen II erhalt man 2-(3-Phenyl-allylthio)-benzimidazol (III 36%), mit 2 Aquivalenten an II l-(3-Phenyl-allyl)-2-(3-phenyl-allyIthio)-benzimidazol (IV 52%) neben einer geringen Menge l,3-Bis-[3-phenyl-allyl)-2-thiono-2,3-dihydro-benzimidazol (V 7%)378. 

Die Ambivalenz bzw. Tautomerie von 2-Mercapto-benzimidazol ist verantwortlich fur seine Fahigkeit, elektrophile Alkine, sowohl am S- als auch am N-Atom zu addieren. In protischen Losungsmitteln (Methanol368,369, 376 oder Acetonitril/Wasser368,376) ist der Angriflf am S-Atom bevorzugt z. B.369. 

Zweifache Addition an 2-Mercapto-benzimidazol zu l-(3-Oxo-3-pke.nyl-propenyl)-2-(3-oxo-3-phenyl-propenylthio) -benzimidazol (44% Schmp. 190-192°) wird mit 3-Oxo-3-phenyl-pro-pin in Acetonitril beobachtet577 ... 

Bei der Reduktion von 2-Sulfo-benzimidazolen I mit Ammonium-formiat entstehen neben 2-Mercapto-benzimidazolen II die desulfurierten Benzimidazole III. Die 2-Mercapto-benzimidazole II selbst werden unter diesen Bedingungen (Erhitzen in Substanz) nicht zum Benzimidazol III reduziert391 ... 

Mercapto-benzimidazol wird von Allyl-bromid in Gegenwart von Natriumhydrogencarbonat zunachst am S-Atom zu 2-Allylthio-benzimidazol (60%) alkyliert. Beim Erwarmen wandert der Allyl-Rest (Claisen-Umlagerung) vom S- zum N-Atom, und man erhiilt l-Allyl-2-mer-capto-benzimidazol (50% Schmp. 115—117°)372. 

Akasaki and Ohno206 recently found that S-phenacyl-2-mercapto-benzimidazole (197) on treatment with benzoyl chloride did not give the expected N-benzoyl derivative but the benzimidazothiazole 198 in quantitative yield. Exploration of the mechanism revealed a complicated sequence of acyl migrations, which, though not yet fully elucidated, may have important biochemical implications, particularly on the mode of action of biotin. 

Reaction of recently synthesized 1 -al kvnyl />-( trifluoromethyl )phenyl]( tetrafluoro-borato)-X3-bromanes with 2-mercapto- benzimidazole or benzothiazole in dichloro-methane at 0°C under argon resulted in a domino Michael addition-carbene rearrangement-cyclization reaction to produce directly tricyclic heterocycles in high yields (Scheme 67).103... 

The route of synthesis of pantoprazole sodium, as described in US patent 4758579 (1988), is as follows. 2-chloromethyl-3,4 dimethoxypyridinium hydrochloride(I) is condensed with 5-difluoromethoxy-2-mercapto-benzimidazole(H) in ethanolic sodium hydroxide solution to yield 5-(difluoromethoxy)-2-(((3,4-dimethoxypyrolidine-2-yl) methyl) thio)-l/7-benzimidazole)(III). This compound is oxidized during reaction with m-chloroperbenzoic acid in methylene chloride, yielding pantoprazole base (IV). Further reaction with aqueous caustic soda solution gives pantoprazole sodium, which is then purified by crystallization from methanol. The various steps of this synthesis are illustrated in Scheme 1. 

SYNS ANTIEGENEMB ANTIOXIDANT MB (CZECH) AOMB ASM MB 2-MERCAPTO-BENZIMIDAZOLE MERCAPTOBENZOIMIDAZOLE 2-MERCAPTOBENZOIMIDAZOLE MERKAPTO-BENZIMIDAZOL (CZECH) NCI-C60980 o-PHENYLENETHIOUREA USAFEK-6540 USAFXF-21... 

Compounds of copper with 2 - mercapto-benzimidazole [109], 2 - methylbenzimidazole [110], and oxyphenylbenzimidazole [111, 112], being introduced at any stage of PA-6 polymerization, being, ay the same time, both dyes and light stabilizers have been of great interest lately. Use of complex compounds is usually forced measure because of the difficulties, connected with introduction of metal copper and its salts into PA. 

Organic compounds such as l-nitroso-2-naphthol, thionalide, 2-mercapto-benzimidazole, and potassium thiocyanate have also been used as coprecipitation reagents. These compounds, except KSCN, are insoluble in water and form insoluble complex compounds with a number of metal ions. Precipitation reagents are first dissolved in small amounts of volatile, water insoluble... 

The general expression of mercapto-benzimidazole and benzoxazole is as follows ... 

Mercapto-benzimidazole is synthesized by adopting phenylamine and CS2 as feeds. Phenylamine and CS2 are heated in naphth3ridines under the condition of heating temperature 80 °C and reaction time 46 h. The product can dissolve in water and alcohol. 

Preparation of mercapto-benzimidazole from o-phenylenediamine and thiocyanate... 

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