Benzimidazole 1 -amino-2-phenyl

Sardesai and Sunthankar studied the cyclization of diethyl )V-(2-amino-phenyl)aminomethylenemalonate (162, R = H) (57MI2 59MI1). No cyclization occurred in refluxing xylene in the presence or absence of a catalyst (p-toluenesulfonic acid or sodium hydroxide), or in acetic anhydride, or in a mixture of acetic anhydride and concentrated sulfuric acid. Benzimidazole and benzimidazolone were obtained in 20% and 66% yields, respectively, when 162 (R = H) was distilled in vacuo. Benzimidazolone was the product when 162 (R = H) was heated in boiling diphenyl ether, o-Phenylenediamine was reacted with diethyl acetylmalonate at 140°C for 4 hr to give 2-methylbenzimidazole and diethyl malonate (85S555). 

Amino-anilino)-l, 2-diphenyl-cyclopropenylium-tetrafluoroborat [mesomer mit (2-Amino-phenyl)-(l,2-diphenyl-cyclopropenyliden)-ammonium-tetrafluoroborat] cyclisiert beim Ver-such der Deprotonierung mit molaren Mengen an Diisopropyl-ethyl-amin (Hunig-Base) unter Ringspaltung zu 2-[(Z)-l,2-Diphenyl-ethenyl -benzimidazol (89% Schmp. 273-2740)59 (vgl. 

So erhalt manz. B, aus 2-Benzylamino-benzoesaure-acyloximid-amiden beim Kochen in Wasser 2-Amino-benzimidazole, wahrend in ethanolischerNatronlauge oder in Pyridin 3-(2-Benzyl-amino-phenyl)-l,2,4-oxadiazole entstehen213. 

Amino-phenyl)-3-methyl- E10b2. 339 [1-(CF, —CHCIF) —benzimidazole + N2H4]... 

A particular case of a photochemical strategy towards functionalized benzimidazoles regards the synthesis of 2-acylamino derivatives 70, which can be obtained from irradiations in methanol of 3-(o-amino)phenyl-l,2,4-oxadiazoles 68. In this reaction, a photolytic cleavage of the ring O—N bond, followed by migration of the aryl substituent, leads to the carbodiimide intermediate 69, a precursor of the benzimidazole nucleus (Scheme 12.20) [47]. 

Amino-phenyl)- XI/1, 371 Amino-phenyl- VIII, 282 Benzimidazol... 

GggHuNgOs 5 (Oder 6)-Aoetammo-2-[3.acet< amino-phenyl]-l-[3-acet amino-benzyl]-benzimidazol 26, 399. ... 

Methyl-2-[2-oxy-phenyl] l [4-dlmetliyl amino-phenyl] benzimidazol 28, 416. 

H CHS c6h5 1h Riickfl. 1 -Amino-benzimidazol l-Amino-2-methyl-... l-Amino-2-phenyl-... 70 69 59 156-156,5 164-165 204-205 ... 

Phenyl-5-pyrazolo)-benzimidazole allgemeine Arbeitsvorschrift206 Einc Mischung von 1,0 g (4,0 mmol) 5-(2-Amino-anilino)-3-phenyl-pyrazol (R1 = H) bzw. 1,0 g (3,6 mmol) 5-(2-Amino-4,5-dimethyl-anilino)-3-phenyl-pyrazol (R1 = CH3) werden mit 5 ml Orthocarbonsaure-triethylester in Xylol 2 h am RiickfluB erhitzt. Nach dem Abziehen des Losungsmittels i. Vak, crhalt man ein Ol, das bei Zugabe von kaltem Diethylether kristallisiert. Die Produkte werden durch Umkristallisieren aus Ethanol gercinigt. 

Aus 3-Amino-2-benzoyl-4,4,4-trichlor-2-butensaure-nitril und 1,2-Diamino-benzol in Pyridin wird 2-(l-Cyan-2-oxo-2-phenyl-ethyl)-benzimidazol (75% Schmp. 185°) erhalten152. 

Erhitzt man l-Methyl-2-phenyl-benzimidazol mit Natriumamid, so erhalt man unter Addition/C,C-Spal-tung und Eliminierung 2-Amino-l-methyl-benzimidazol (55%)433 ... 

The dialkylaminoalkyl residue may also be connected directly to the phenyl residue of the acetoacetanilide. By coupling with diazotized 2-(4-aminophenyl)-benzimidazole, a yellow dye suitable for paper is formed [15]. The dialkylaminoalkyl group may be connected to the N1 atom of 3-methylpyrazolone [16], to the amide nitrogen atom of Ar-phcnylpyrazolonc-3-carbonamide [17], to the N2 atom of 3-cyano-2,4,6-trisaminopyridine [18], or to the amino group of 2-amino-4,6-dihydroxypyridine [19],... 

These s.c. poly[(benzoylene)-s-triazoles] have poorly defined structure since the cyclization reaction is incomplete. Since the photoconductivity is higher when a substantial amount of unreacted amino groups are left in the structure these polymers and oligomers could be classified as polymers with photoconductive amino group. Voishchev et al.4i recently reported photoconductive properties of poly-[N-phenyl)benzimidazoles] such as... 

The interaction of perfluoro-5-azanon-4-ene with amidines and 2-amino-benzimidazole occurs with formation of a six-membered heterocycle, giving 2,4-bis(heptafluoropropyl)-6-phenyl-[l,3,5]triazine, 2,4-bis(hep-tafhioropropyl)-6-methyl-[l,3,5]triazine, and a tricyclic compound—2,4-bis(heptafhioropropyl)benz-[4,5]imidazo[l,2-tf][l,3,5]triazine (01IZY457). 

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],... 

Tu and co-workers [103] have elaborated an efficient microwave-assisted synthesis of 4,5-bis-phenyl substituted benzo[4,5]imidazo[l,2-a]pyrimidines 59 through a MCR of an aromatic aldehyde with 1,2-diphenylethanone and 2-amino-benzimidazole. PEG-300 was used as an inexpensive, nontoxic, and recyclable reaction medium which can be reused up to three times without reduction of the product yield although a weight loss of 10% PEG was observed per cycle (Scheme 43). 

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-... 

SYNS 2-AMINO-5-BENZOYLBENZIMIDAZOLE BENZIMIDAZOLE, 2-AAnNO-5-BENZOYL- G-1029 KETONE, 2-AMINO-5-BENZIMIDAZOLYL PHENYL METHANONE, (2-AMINO-1 H-BENZIMIDAZOL-5-YL)PHENYL- R 18986... 

METHANONE, (2-AMINO-1H-BENZIMIDAZOL-5-YL)PHENYL- see AIHOOO METHANONE, (4,5-DICHLORO-l H-PYRROL-2-YL)(2,6-DIHYDROXYPHENYL)- see POK400 METHANONE, (4-(2-... 

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... 

Amino-5-phenyl-l,2,4-oxadiazole and 1 gave enamino-ketone 188 that on irradiation with a low-pressure mercury lamp gave benzimidazole 189 as a result of a photoinduced rearrangement of the 1,2,4-oxadiazole ring (88JHC1551) (Scheme 32). 

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