Benzimidazole 2-phenyl-5 -nitro

Pyrimidin 6-Amino-2,4-dioxo-3-phenyl-l,2,3,4-tetrahydro- E15/2, 2228 [ —R—OH(Cyclokond.)] lH- 6-Nitro-2,3-dihydro- IV/la, 182 Quinolin 4-Hydrazino-6,7-methylen-dioxy- E16a, 700 (Cl - NH-NH2) Quinolin-l-oxid 2-Amino-3-aminocarbonyl- E7a, 504 [2-N02 - Ar -CH = C(CN) -CO —NH2/Pt]... 

Amino-6-hydroxy-4-hydroxy-methyl-3-phenyl- E9a, 589 (7-OH — 4-Ar — < 1,2-oxazolo-[3,4-d]pyridazine)/Red.) Pyrido[l,2-a]benzimidazol 7-Nitro-... 

Phenylbenzimidazole is nitrated first at the 5-position with mixed acid, and subsequent reaction produces 5-nitro-2-(4-nitrophenyl)-and 5-nitro-2-(3-nitrophenyl)-benzimidazole. 2-Phenyl-, 2-(4-nitro-phenyl)- and 5-nitro-2-phenyl-benzimidazole are nitrated as their conjugate acids. ... 

Bei der Hydrierung von aromatischen bzw. heteroaromatischen Nitro-alkenen mit in situ aus Benzaldehyd und 1,2-Diamino-benzol in Butanol hergestelltem 2-Phenyl-2,3-dihydro-benzimidazol werden keine Nebenprodukte gebildet und man erhalt selektiv l-Aryl-2-nitro- bzw. l-Hetaryl-2-nitro-alkane in Ausbeuten von 70-90% ... 

In the case of benzimidazole itself, nitration usually occurs at the 5-position (80MI1). Sterba and co-workers have studied the nitration of some arylbenzimidazoles and have showed that 2-phenyl benzimidazole, when treated with nitric acid sulfuric acid at 10°C, gives 6-nitro-2-phenyl-benzimidazole (75%). The 2-(3-nitrophenyl) and 2-(4-nitro phenyl) benzimidazoles similarly yield the 6-nitro products (57 and 97% respectively), and nitration of 6-nitro-2-phenylbenzimidazole gives the 2-(4-nitrophenyl) and 2-(3-nitrophenyl) products in 44% and 32.5% yields, respectively (65CCC1093). 

A reaction of 4-nitro-l,2-phenylendiamine with benzotrichloride in the presence of sodium methylate [367] has been described. In this case 2-phenyl-5(6)-nitroben-zimidazole is obtained without preliminary extraction of the ortho-ester of benzoic acid. Sometimes acylated polynitroanilines, with one of the groups in the orthoposition to the amino group, are used as the initial products. On partial reduction of such compounds the cyclization to benzimidazoles takes place [85, 368], For example, the reduction of 2,4-dinitroacetanilyde with ammonium sulfide has afforded 2-methyl-5(6)-nitrobenzimidazole (Scheme 2.41) [85],... 

Azido-6-chlorsulfonyl- 962 2-Azido-5-nitro- 964 2-(2-Azido-phenyl)- 1016 2-(Azocano-thiocarbonylthio)- 973 2-[4-(Benzimidazol-2-ylamino)-bcnzolsulfonyl-amino]- 885... 

Benzoxadiazines are also formed in the reaction of nitrile oxides with nitrosoben-zene.29 Thus, using benzonitrile oxide and nitro so benzene an unstable nitrosonitrone 9a is formed, which, when dissolved in a mixture of nitromethane and diethyl ether and left at — 20°C, decomposes to a mixture of 2-phenyl-1//-benzimidazole-l-ol 3-oxide (10a) and 3-phenylbenzoxadiazine 12a (23%), possibly via an intermediate l,2,4-benzoxadiazin-4-ol 11a. 

Best activity was obtained when = naphthyl, p-fluorophenyl or m-nitro-phenyl. A small substituent at Y, for example Me enhanced, and a large substituent, for example Ph decreased activity from Y = H. Z = H or Me were very similar in activity. Eight out of 122 benzimidazole derivatives were claimed to have an ED50 value of about 16 mg/kg but no estimate was given of the toxicity of these compounds. 

The VNS is the reaction of choice for incorporation of a-sulfonylalkyl substituents into nitroarenes and their heteroanalogues. Particularly accessible and useful are nitroarylmethyl phenyl sulfones and their heteroanalogues that are efficiently produced in the VNS reactions of carbanions of chloromethyl aryl sulfones with a great variety of nitroarenes and nitroheteroarenes. Nitro derivatives of heterocycles, such as pyrrole [54,55], furan [54], thiophene [54], imidazole [106, 112, 113], pyrazole [114], pyridine [57], indole [115], indazole [116, 117], benzimidazole [118], benzotriazole [119], benzofuroxan [120], quinoline [121], and porphyrins [122, 123], have been shown to enter this reaction. 

N itto-phenyl1-benzimidazol 28, 234. 2-[3-Nitro-phenyI].benzimldazoI 28, 235. 2-[4-Nitto-phenyl]-benzimidazol 28, 235. Lactam der 2 -Amino-diphenyInitTosamm-oaTbonefiaie-(2) 24 II 97. 

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