Benzene, diamino

Synthesis by high-dilution techniques requires slow admixture of reagents ( 8-24 hrs) or very large volumes of solvents 100 1/mmol). Fast reactions can also be carried out in suitable flow cells (J.L. Dye, 1973). High dilution conditions have been used in the dilactam formation from l,8-diamino-3,6-dioxaoctane and 3,6-dioxaoctanedioyl dichloride in benzene. The amide groups were reduced with lithium aluminum hydride, and a second cyclization with the same dichloride was then carried out. The new bicyclic compound was reduced with diborane. This ligand envelops metal ions completely and is therefore called a cryptand (B. Dietrich, 1969). 

Malononitrile (133) undergoes Pd(0)-catalyzed dimerization to give 134[125,126]. The trimerization of malononitrile in boiling benzene catalyzed by potassium tetrakis(pentalluorophenyl)palladate gives 4.6-diamino-3,5-dicyano-2-cyanomethylpyridine (135)[127]. 

DiaminO 4,4-dimethyl-l,3,5-thiadiazine hydrobromide was isolated as by-product (418). Benzene sulfonates of cyanohydrin prepared from sodium cyanide and an halobenzoaldehyde, when treated with thiourea or its derivatives, afford 2,4-diamino-5-(p-halogenophenyl)-thiazole benzene sulfonates (447). Similarly, cyanoamido thiocarbamates obtained from cyanamide and isothiocyanates yield substituted 2,4-diaminothiazoles (598). 

Benzimidazoles are generally synthesized from ortho-diamino-benzenes and carboxylic acid derivatives. The antihistaminic agent, clemizole (60), for example, can be prepared by first reacting ortho-diaminobenzene (57) with chloroacetic acid to form 2-chloro-methylbenzimidazole (58). Displacement of the halogen with pyro-... 

Benzene-1,2-diamine or derivatives are generally employed as the diamino component in ring-closure reactions with 1,2-dicarboxylic acids or derivatives (Table 2). 

V Disodium 4,4 -(2,4-diamino-5-methyl-l,3-phenylene-bisazo)di(benzene-sulfonate)... 

Ning, J., Li, R., Shen, X., Qian, Z., Hou, S., Rocha, A.R. and Sanvito, S. (2007) First-principles calculahon on the zero-bias conductance of a gold/l,4-diamino-benzene/gold molecular junchon. Nanotechnology, 18, 345203-1—345203-6. 

Bis(diamino)alanes (R2N)2A1H were used for the hydroalumination of terminal and internal alkenes [18, 19]. TiCb and CpjTiCb are suitable catalysts for these reactions, whereas CpjZrCb exhibits low catalytic activity. The hydroaluminations are carried out in benzene or THF soluhon at elevated temperatures (60°C). Internal linear cis- and trans-alkenes are converted into n-alkylalanes via an isomerization process. Cycloalkenes give only moderate yields tri- and tetrasubstituted double bonds are inert. Hydroaluminahon of conjugated dienes like butadiene and 1,3-hexa-diene proceeds with only poor selechvity. The structure of the hydroaluminahon product of 1,5-hexadiene depends on the solvent used. While in benzene cyclization is observed, the reaction carried out in THF yields linear products (Scheme 2-10). 

Sapse et al.41b performed ab initio calculations on benzene-benzene as a model for the interaction between the a phenylalanine residue and the benzoyl portion of a typical folate compound. In addition, that study examined the complex formed hy a benzene ring and a polar serine which acts as a hydrogen donor, between a benzene ring and the amino group of a meta diamino-imidazole group (present in some anti-folates) and between serine as a hydrogen donor and the diamino-imidazole group as the electron donor. 

A method for the preparation of 1,3,2-diazaphospholidine heterocydes has been described by Deng and Chen (Scheme 6.225) [402], The authors found that treating hindered 1,2-diamino substrates such as a-amino acid amides with tris(diethylami-no)phosphine as reagent/solvent under open-vessel microwave conditions at 250 °C for 1 min furnished a trivalent phosphorus intermediate. Subsequent thiation of this intermediate with elemental sulfur in refluxing benzene provided the target l,3,2-diazaphospholidin-4-ones in good overall yields. The yields were much improved compared to those achieved by standard thermal methods. 

Equimolar quantities of 2,4-diamino-l,5-benzenediol dihydrochloride and isophthalic acid were mixed in fresh poly (phosphoric acid) using a high-shear stirrer under a slow stream of nitrogen gas. The system was heated at 40°C for 6 hours, at CG°C for 18 hours, at 120°C for 6 hours, at 160°C for 8 hours, and at 220°C for 24 hours. The resultant mixture was dark brown. The polymer was precipitated from water. After filtration and washing with water and methanol, the solid product was then dissolved in methane-sulfonic acid, filtered and precipitated by the addition of methanol. The solid was washed with concentrated ammonium hydroxide, water, methanol, methanol/benzene mixtures (with a volume ratio of 1/1), and finally benzene. The final product was dark brown. 

D. 2,3-Diamino pyridine (Note 12). In an apparatus for catalytic hydrogenation (Note 13) 56.4 g. (0.3 mole) of 2,3-diamino-5-bromopyridine suspended in 300 ml. of 4% sodium hydroxide solution is shaken with hydrogen in the presence of 1.0 g. of 5% palladized strontium carbonate (Note 14). When absorption of hydrogen is completed, the catalyst is removed by filtration, and, after saturation with potassium carbonate (about 330 g. is required), the resulting slushy mixture is extracted continuously with ether until all the precipitate completely disappears (usually about 18 hours, but this depends on the efficiency of the extraction apparatus). The ether is removed by distillation, and the residue of crude 2,3-diaminopyridine is recrystallized from benzene (about 600 ml. is required) using 3 g. of activated charcoal and filtering rapidly through a preheated Buchner funnel. The yield of 2,3-diaminopyridine, obtained as colorless needles, m.p. 115-116°, pKa 6.84, is 25.5-28.0 g. (78-86%) (Note 15). 

Photolytlc. The dye-sensitized photodecomposition of ametryn was studied in aqueous, aerated solutions (Rejto et al, 1983). When an aqueous ametryn solution was irradiated in sunlight for several hours, 2-(methylthio)-4-(isopropylamino)-6-amino-5-triazine and 2-(methylthio)-4-(iso-propylamino)-6-acetamido-5-triazine formed in yields of 55 and 2.6%, respectively. Continued irradiation of the solution led to the formation of 2-(methylthio)-4,6-diamino-5-triazine which eventually decomposed to unidentified products (Rejto et al., 1983). The UV (7, = 253.7 nm) photolysis of ametryn in water, methanol, ethanol, n-butanol, and benzene yielded the 2-//analog 4-(ethylamino)-6-isopropylamino-5-triazine. Photodegradation was not observed at wavelengths >300 nm (Pape and Zabik, 1970). 

Watanabe T, Ishihara N, Ikeda M. 1976. Toxicity of and biological monitoring for 1,3-diamino-2,4,6-trinitrobenzene and other nitro-amino derivatives of benzene and chlorobenzene. Int Arch Occup Environ Health 37 157-168. 

Fig. 18. The product of reaction between Al(i-Bu)3 with N,JV -bis(2-hydroxybenzyl)-l,2-diamino-(4,5-dimethyl)benzene [211]...

Quantitative determination of diacetyl and 2,3-pentanedione during beer fermentation was achieved by GC/MS method as 2,3-dimethylquinoxaline and 2-ethyl-3-methylquinoxaline, respectively, after reacting with 1,2-diamino-benzene <2006MI52>. 

The amino structure for 9-aminoacridine (77) has been confirmed by IR studies (65JCS5230), and NMR spectral data in DMSO are consistent with the diamino structures (78) and (79) (64JCS1423). Amino groups on fused benzene rings and (3 to nitrogen in hetero rings exist in the amino form, and the reactions of these compounds are similar to those of aniline and the naphthylamines. Aminopyridine JV-oxides exist very predominantly in the amino form (57JCS4375). 

The high reactivity of (41) also allows the addition of amines. For example, 41a reacts with 1,2-diamino-benzene to diazepine 72 without isolation of an intermediate in a one-pot reaction (90TH1). (See Fig. 33.)... 

Preliminary results in the validation of a novel short term test. Mutat. Res., 46, 305-310 Watanabe, T., Ishihara, N. Ikeda, M. (1976) Toxicity of and biological monitoring for 1,3-diamino-2,4,6-trinitrobenzene and other nitro-amino derivatives of benzene and chlorobenzene. Int Arch, occup. environ. Health, 37, 157-168 Yoshimi, N., Sugie, S., Iwata, H., Niwa, K., Mori, H., Hashida, C. Shimizu, H. (1988) The genotoxicity of a variety of aniline derivatives in a DNA repair test with primary cultured rat hepatocytes. Mutat. Res., 206, 183-191... 

Benzobisthiazole random copolymers (X) [38] were also prepared using 2-methyl terephthalic acid and terephthalic acid with l,4-dimercapto-2,5-diamino-1,4-benzene dihydrochloride. Various copolymers provided materials with a wide range of crosslink densities. High quality fibers with spin draw ratios as high as 50 to 1 were obtained by dry-jet wet spinning of anisotropic polymerization mixtures. Heat treatment of the fibers was carried out in a tube oven... 

Substitution of the 1,4-phenylene unit with 2,5-thiophene has also been investigated as a backbone deviation in PBZT [49] and PBZO [50] systems. A catenation angle of 148° was introduced in both systems resulting in anisotropic reaction mixtures at concentration above 10% by weight. Evers et al. polymerized the mono, di and tri-thiophene moieties as diacid chlorides with l,4-dimercapto-2,5-diamino-1,4-benzene dihydrochloride in PPA to give polymers with intrinsic viscosities in the range of 5-8 dL/g. All these materials... 

Dinitro-2, 4-diamino-azobenzene, 02N.CgH4.N N.CgH2(N02)(NH2)2 orn-color-ed powd, colors acetate rayon a golden yel, was prepd by coupling 4-nitro-l, 3-diamino-benzene with 4-nitroaniline (Ref 1)... 

DIAMINOBENZENE AMD DERIVATIVES Di ami no benzene, Phenylenediamine, or Amino-aniline (called Diamino-benzol or Phenylen-diamin in Ger), N.CgH. NH mw 106.12,... 

Diamino-N. N,nKn1 -tetrametbyl)-benzene, stable oil when dry, having a camphor-like odor, bp 215-16° at 759mm press forms cryst salts (Ref 1)... 

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