Diphenyl benzimidazole

In several instances similar transformations were conducted under base-free conditions. Thus, heating 7V,7V -diphenylbenzamidine 112 with hydrogen peroxide at 80 °C leads to the formation of 1,2-diphenyl benzimidazole 114 in 67% yield (Scheme 34) (99IZV626). Though the mechanism of this conversion remains unclear,... 

THF, tetrahydrofuran DMF, dimethylformamide DMSO, dimethyl sulfoxide DPSO, diphenyl sulfoxide en, ethylenediamine py, pyridine pic, picoline lut, lutidine nic, nicotinamide IMD, imidazole MelMD, N-methylimidazole 1-Cl-nap, 1-chloronaph-thyl acac, acetylacetonyl anion, CH3COCHCOCH3 C4H9O3, acetoacetic ester anion, CH3COCHCOOC2HS C4H,oN2, piperazine C7HSN2, benzimidazole. 

Fig. 1 Micellar effects upon reaction of p-nitrophenyl diphenyl phosphate with benzimidazolide ion (solid points) open points are for reaction in the absence of benzimidazole , 10 4 M benzimidazole, pH 10.7 , 1.2 x 10-4 M benzimidazole, pH 11 O, pH 10.7, and 11 respectively. The solid lines are theoretical. (Reprinted by permission of the American Chemical Society)...

Fig. 6 Reaction of p-nitrophenyl diphenyl phosphate in non-micellar aggregates of tri-n-octyl ethylammonium mesylate (TEAMs) at pH 10.7 , 10 4M naphth-2,3-imidazole and O, 10-4 and 2 x KT4 M benzimidazole, respectively. (Reprinted with permission of the American Chemical Society)...

Several routes have been reported for the synthesis of aromatic poly(azole)s such as poly(benzimidazole), poly(benzoaxazole), and poly(benzthiazole) melt polycondensation of dicarboxylic acid diphenyl esters with tetramines21 and high-temperature solution polycondensation of dicarboxylic acids or their derivatives with tetramine hydrochlorides in PPA.22 PPA acts as condensing agent and solvent. Ueda etal.23 developed a modified method for the synthesis ofpolyazoles with the use of PPM A. 

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). 

Polyimides are obtained from amine and carboxyl reactants when the ratio of amine to acid functional groups is 1 2. If reactants with the reverse ratio of amine to acid functional groups are employed, polybenzimidazoles (PBI) are produced for instance, polymerization of 3,3 diaminobenzidine and diphenyl isophthalate yields poly[(5,5 -bi-liT-benzimidazole]-2,2 -diyl)-l,3-phenylene] (Lilia) (Eq. 2-216) [Buckley et al., 1988 Hergenrother, 1987 ... 

The technical production of poly(benzimidazole) (PBI) is also carried out in two steps. In the first step an aromatic tetramine is condensed with the diphenyl ester of an aromatic dicarboxylic acid at 220-260 °C, yielding a poly(amino amid) with elimination of phenol. Ring closure with elimination of water occurs in the second step (solid-phase polycyclocondensation), conducted at 400 °C and yielding the polybenzimidazole (experimental procedure, see Table 2.3). 

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. 

Bei der Thermolyse von N,N-Diphenyl-thioharnstofFen entsteht iiber radikalische Zwischenstufen u. a. 2-Phenyl-benzimidazol (10%)12 ... 

Sekundare Nitro-alkane liefern die tiefgefarbten 2,2-disubstituierten 2H-Benzimidazo 1-1,3-bis-oxide322 324 eine Verbindung dieses Typs wird auch mit Diazo-diphenyl-methan326 er-halten. Mit Formaldehyd/Alkali320 bzw. Formaldehyd/prim. Amin327 entstehen 1,3-Dihydroxy-2,3-dihydro-benzimidazole ... 

Benzofurazan-l-oxid reagiert mit C,N-Diphenyl-nitron unter Bildung von l-Hydroxy-2-phe-nyl-benzimidazol-3-oxid (80%)334 ... 

Poly(arylene ether benzimidazole)s have received more attention than any other PAE containing heterocyclic units. This is due primarily to their unique combination of properties even at relatively low molecular weights and their potential for use in several high performance applications. The initial report in 1991 involved polymers from the reaction of 3 different bis[(4-hydroxy-phenyl)benzimidazole]s with various activated aromatic difluoro monomers as shown in Eq. (10) [37]. The bis[(4-hydroxyphenyl)benzimidazole]s were prepared from the reaction of aromatic bis(o-diamines) and phenyl-4-hydroxybenzoate in diphenyl sulfone. The use of 4-hydroxybenzoic acid would obviously reduce the... 

Substituted benzimidazoles have been reported to be readily obtained by photolysis of l,2,4-oxadiazol-5-ones. Thus, irradiation of dioxane solutions of 3,4-diphenyl-l,2,4-oxadiazol-.5-one (CCXLVII ) and of 3-carbalkoxy-2-phenyl-l, 2,4-oxadiazol-5-one (CCXLIX) with ultraviolet light yielded 2-phenyl- (CCLa),5 and 2-carbalkoxybenzimidazoles (CCLb), 6 respectively. 

The mesoionic pyrimidine 243349 (from carbon suboxide and 4,6-dimethyl-2-methylaminopyrimidine) added DMAD (and dicyanoacetyl-ene and 1,3-diphenyl- l-oxoprop-2-yne) in boiling xylene giving a good yield of the pyrido[l,2-a]pyrimidin-6-one (245). Phenylpropiolic ester and EP merely converted 243 back into 4,6-dimethyl-2-methylaminopy-rimidine. The fused pyrimidine 247, obtained from benzimidazole (246)... 

The photolysis of the meso-ionic 1,4-diphenyl-1,2,4-triazol-3-one (200, R1 = R3 = Ph, R2 = H) was stated97 to yield phenyl isocyanate (13%), iV.N -diphenylurea (23%), and the bicyclic compound 215 (49%). These results were interpreted in terms of the fragmentation of the photo-intermediate 213 yielding the JV-phenyldiazirine (214).97 A later publication by the same group97b reports different results. Photolysis of meso-ionic 1,4-diphenyl-1,2,4-triazol-3-one (200, R1 = R3 = Ph, R2 = H) was stated to yield97 phenylisocyanate and the bicyclic compound 215. Later studies,7b have shown that the bicyclic compound 215 is not produced by the photolysis of 200, R1 = R3 = Ph, R2 = H. Irradiation in methanol-methylene chloride gave methyl phenylcar-bamate (25%), benzimidazole (18%), and azobenzene (7%). 

The reaction of succinic acid anhydride 111 with 2-methyl-2,4-diphenyl-2,3-dihydroli/-benzo[Z ][l,4]diazepine 112 in toluene in the presence of potassium carbonate leads to 4-(2-methyl-2,4-diphenyl-2,5-dihydro-l/f-l,5-benzodiazepin-5-yl)-4-oxobutanoic acid 113 in 70% yield [110], while its treatment with 2,4-diphenyl-2,3-dihydro-l//-l,5-benzodiazepine 104 follows with chalcone elimination and yields 3-(benzimidazol-2-yl)propionic acid 114 [115] (Scheme 4.36). 

The best listing of fungicides that we know of is published annually by the Meister Publishing Company of Willoughby, Ohio in their Farm Chemicals Handbook. They list the following compounds or types of compounds as officially "registered" for use on plants in the United States allyl alcohol, ammonium isobutyrate, antibiotics, benzimidazole types, carbofuran, cadmiums, captan types, coppers, carboxin, dehydroacetic acid, Dexon (sodium [4-(dime thy lamino) phenyl diazo sulfonate), diphenyl,... 

Diphenyl tellurium bis[trifluoroacetate] reacted under the same conditions with tetrame-thylurea, sulfoxides, triphenylphosphane oxide and sulfide, triphenylarsane oxide, pyridine 1-oxides, tetramethylpiperidine, benzimidazole, morpholine, and 7V,Ar-diphenylthiourea to give 1 1 complexes as sharp-melting, colorless solids that are soluble in common organic solvents3. 

PB PBI PBMA PBO PBT(H) PBTP PC PCHMA PCTFE PDAP PDMS PE PEHD PELD PEMD PEC PEEK PEG PEI PEK PEN PEO PES PET PF PI PIB PMA PMMA PMI PMP POB POM PP PPE PPP PPPE PPQ PPS PPSU PS PSU PTFE PTMT PU PUR Poly(n.butylene) Poly(benzimidazole) Poly(n.butyl methacrylate) Poly(benzoxazole) Poly(benzthiazole) Poly(butylene glycol terephthalate) Polycarbonate Poly(cyclohexyl methacrylate) Poly(chloro-trifluoro ethylene) Poly(diallyl phthalate) Poly(dimethyl siloxane) Polyethylene High density polyethylene Low density polyethylene Medium density polyethylene Chlorinated polyethylene Poly-ether-ether ketone poly(ethylene glycol) Poly-ether-imide Poly-ether ketone Poly(ethylene-2,6-naphthalene dicarboxylate) Poly(ethylene oxide) Poly-ether sulfone Poly(ethylene terephthalate) Phenol formaldehyde resin Polyimide Polyisobutylene Poly(methyl acrylate) Poly(methyl methacrylate) Poly(methacryl imide) Poly(methylpentene) Poly(hydroxy-benzoate) Polyoxymethylene = polyacetal = polyformaldehyde Polypropylene Poly (2,6-dimethyl-l,4-phenylene ether) = Poly(phenylene oxide) Polyp araphenylene Poly(2,6-diphenyl-l,4-phenylene ether) Poly(phenyl quinoxaline) Polyphenylene sulfide, polysulfide Polyphenylene sulfone Polystyrene Polysulfone Poly(tetrafluoroethylene) Poly(tetramethylene terephthalate) Polyurethane Polyurethane rubber... 

Amino-6-nitro-Fischer s base (36, R = N02) was reduced to the 5,6-diamino compound (36, R = NH2) in 80% yield, which (as its hexachlorostannate salt) was condensed with benzoic acid and with benzil to give, respectively, a 68% yield of 5,7,7-trimethyl-6-methylene-6,7-dihydro-5 7/-pyrrolo[2,3-/]-benzimidazole (37) and a 62% yield of 6,8,8-trimethyl-7-methylene-2,3-diphenyl-7,8-dihydro-6 7/-pyrrolo[2,3-g]quinoxaline (38).42 Spiropyrans from these linearly annellated Fischer s bases were not reported they likely would color upon irradiation with blue light. 

MePTZ = lO-methylphenothiazine 2,3-dpp = 2,3-bis (2-pyridyl)pyrazine 2,9-Me2-4,7-Ph2-phen = 2,9-dimethyl-4,7-diphenyl-l,10-phenanthrolme 2,9-Me2-phen = 2,9-dimethyl-1,10-phenanthroline 3,4,7,8-Me4-phen = 3,4,7,8-tet-ramethy 1-1,10-phenanthroline 4,4 - NH2 2-bpy = 4,4 -dia-mino-2,2 -bipyridine 4,4 -Me2-bpy = 4,4 -dimethyl-2,2 -bipyridine 4, 4 -Ph2-bpy = 4,4 -diphenyl-2,2 -bipyridine 4, 4 - Bu2-bpy = 4,4 -di-tert-butyl-2,2 -bipyridine 4,7-Me2-phen = 4,7-dimethyl-l,10-phenanthroline 4-MeOPh-HPh bpy = 4 -(4-methoxyphenyl)-6 -phenyl-2,2 -bipyridine 4-Me-phen = 4-methyl-1,10-phenanthroline 5,6-Me2-phen = 5,6-dimethyl-l,10-phenanthroline 5-Ph-phen = 5-phenyl-1,10-phenanthroline bimy = benzimidazol-2-ylidene biq = 2,2 -biquinoline bpy = 2,2 -bipyridine bpy-dvb-bpy = 1,4-bis[2-(4 -methyl-2,2 -bipyrid-4-yl)ethenyl]benzene bpy-pyrl = 4-(2-pyrrol-l-ylethyl)-4 -methyl-2,2 -bipyridine bpy-pyr2 = 4,4 -bis((3-pyrrol-l-ylpropyloxy)carbonyl)-2,2 -bipyridine BSA = bovine serum albumin BTA = bis(trimethylsilyl)acetylene chrysi = 5,6-chrysenequinone diimine COD = 1,5-cyclooctadiene DAB = 1,4-diaza-1,3-butadiene DFT = density functional theory dmb =1,8-diisocyano-/ -menthane dmb-tol = 4-methyl-4 -(iV-methyl-/ -tolylaminomethyl)-2,2 -bipyridine dmpe = l,2-bis(di-methylphosphino)ethane dmpm = bis(dimethylphosphino) methane dpmp = bis(diphenylphosphinomethyl)phenylphos-phine dppb = l,2-bis(diphenylphosphino)benzene dppe = l,2-bis(diphenylphosphino)ethane dpp-HCNN = 2,9-di-... 

When the dihydro-1,2,4-triazinone (194) is heated at 180 °C under reducing conditions there is rupture of the 1,2-bond followed by ring closure, producing 4,5-diphenyl-imidazolinone (195). Such reductive ring closures of benzotriazine 1-oxides (196) can give benzimidazoles, in particular 2-(4-thiazolyl)benzimidazoles (197) ( thiabendazole ). Similar reactions take place with 1,3,5-triazines. In fact, primary amines cleave the compounds completely with evolution of ammonia and formation of iV.iV -disubstituted formamidines. With suitable primary amines, though, this reaction can be designed to produce imidazolines or benzimidazoles (Scheme 113). 

Cyanopyrazine with dicyanodiamide [(NH2CN)2] gave the 2-(4, 6 -diamino-triazin-2 -yl)pyrazine (63), with o-phenylenediamine in the presence of poly-phosphoric acid at 250 gave 2-(benzimidazol-2 -yl)pyrazine, and with hydrazine gave 2-(C-hydrazino-C-iminomethyl)pyrazine, which condensed with benzil to 2-(5, 6 -diphenyl-as-triazin-3 -yl)pyrazine (64) (1441). 

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