1.2- Diaminobenzene, reaction with

Reaction with an amino-propyl derivative of glass or hornblende with glutaraldehyde cross-linking reaction with titanium(iv) oxide coated with polymerized, diazotized 1,3-diaminobenzene Reaction with agarose activated with 4-benzoquinone Reaction with agarose cyclic imidocarbonate... 

Reaction with a copolymer of glutaraldehyde and diaminobenzene Reaction with beads of derivatized, macroreticular polystyrene 5.3.1.18 Reaction with a copolymer of... 

Aminoacroleins enter the transamination reaction with 1,2-diaminoethane to furnish bis adduct 217, whereas with 1,2-diaminobenzene they yield the 2 2 macrocyclic adduct 218 (77CZ161). 

Diaminobiphenyl (former name benzidine) can be easily bisdiazotized, but is not cleanly monodiazotized by reaction with one equivalent of a nitrosating agent. However, 4-aminobiphenyl-4,-diazonium ions are formed in a triazene equilibration of a 1 1 mixture of 4,4 -diaminobiphenyl with biphenyl-4,4 -bisdiazonium salts in aqueous HC1 (Tauber, 1894 see also Sec. 13.4). Methods for mono- and bisdiazotiza-tion of 1,4-diaminobenzene (/ -phenylenediamine) have been described by Saunders and Allen (1985, p. 29 see also Sec. 2.2). 

Selenium(IV) reacts with substituted 1,2-diaminobenzene or 2,3-diamlnonaphthalene in acidic solution to form stable cyclic derivatives which can t>e extracted into an organic solvent and analyzed by gas or liquid chromatography [682,683]. With chloro-, bromo-, or nitro-substituents the plazselenols can be determined with an electron-capture detector at the low picogram level. Se(VI) does not form piazselenol derivatives so the reaction with diaminobenzene can be used to determine the concentration of Se(IV) and Se(VI). Selenium(VI) may be redu to Se(IV) with... 

Attempts to directly iodinate quinoxaline failed, and the synthesis of 2,3-diphenyl-5,8-dibromoquinoxaline is somewhat more involved (Scheme 9) [61]. Starting from ort/zo-phenylenediamine, reaction with SOCI2 gives benzothia-diazole in high yield. Bromination in HBr furnishes 4,7-dibromobenzothiadi-azole, which can be alkynylated or directly reduced [62]. Reduction of the dibromide with sodium borohydride leaves the halide substituents unmolested but opens the ring to furnish l,4-dibromo-2,3-diaminobenzene. Reaction of this intermediate with a 1,2-dione furnishes a 2,3-disubstituted 5,8-dibromo-quinoxaline. Pd-catalyzed alkynylation finishes the sequence off and removal of the TMS groups yields the desired 5,8-diethynylquinoxaline monomers (Table 9, entries 13,14). 

Gawinecki and co-workers reported the structural determination of isomeric products from a similar reaction, the condensation of 1,2-diaminobenzenes 197 with 1,2-dicaibonyl compound 196 <99T8475>. The two different regioisomeric quinoxalines 198, which were produced in nearly equal amounts, were distinguished through the use of advanced NMR techniques including 2D z-gradient selected H, N HMBC. 

The analogous reaction with 1,2-diaminobenzene 201 was reported by Komberg and coworkers in another quinoxaline library production <99JHC1271>. Quinoxaline 202 was a key intermediate in this methodology. 

Template reactions between malonaldehydes and diamines in the presence of copper(II), nickel(II) or cobalt(II) salts yield neutral macrocyclic complexes (equation 15).99-102 Both aliphatic102 and aromatic101 diamines can be used. In certain cases, non-macrocyclic intermediates can be isolated and subsequently converted into unsymmetrical macrocyclic complexes by reaction with a different diamine (Scheme ll).101 These methods are more versatile and more convenient than an earlier template reaction in which propynal replaces the malonaldehyde (equation 16).103 This latter method can also be used for the non-template synthesis of the macrocyclic ligand in relatively poor yield. A further variation on this reaction type allows the use of an enol ether (vinylogous ester), which provides more flexibility with respect to substituents (equation 17).104 The approach illustrated in equation (15), and Scheme 11 can be extended to include reactions of (3-diketones. The benzodiazepines, which result from reaction between 1,2-diaminobenzenes and (3-diketones, can also serve as precursors in the metal template reaction (Scheme 12).101 105 106 The macrocyclic complex product (46) in this sequence, being unsubstituted on the meso carbon atom, has been shown to undergo an electrochemical oxidative dimerization (equation 18).107... 

In the case of the dye from perylenetetracarboxylic diimide [C.I Sulphur Red 14 [67923-45-9], the dianhydride of perylenetetracarboxylic acid is treated with 1,3-diaminobenzene, the diamino compound is then diazotized, and the SCN groups are inserted by the Sandmeyer reaction with NaSCN (24)] [8],... 

N-monosubstituted 1,2-diaminobenzenes react with Appel salt 20 in dichloromethane to give the corresponding 2-cyanobenzimidazoles 87 either directly or through thermal or acid-catalyzed rearrangement of the intermediate imino-l,2,3-dithiazoles 88, which can be isolated (Scheme 9). The reaction mechanism includes reversible attack of the o-amino group on the dithiazole ring <1998T9639>. 

The reaction of lithiated 1,2-diaminobenzene 13 with the methylene diarsane 14 (4 1 ratio) in toluene unexpectedly yielded the lithium 1,3,2-benzodiazaarsolide 15, isolated as coordination polymer (Equation 4). Attempts to prepare thel,3,2-benzodiazaarsolide 15 from As(NMe2)3 failed <2001CC2480>. 

Formyltellurophenes were reacted with hydroxylamine, hydrazine, 1,2-diaminobenzene, 1,3-bifunctional compounds with activated methylene groups, and lithium aluminum hydride. On reaction with hydroxylamine, oximes are formed1. 

The diaminobenzenes (phenylenediamines) are prepared by reduction of 1,3-dinitrobenzene and 2- and 4-nitroanilines. o-Phenylenediamine is of value in the synthesis of a range of nitrogen heterocycles. Thus reaction with organic acids produces benzimidazoles (8). With 1,2-dicarbonyl compounds, quinoxalines (9) are produced. Treatment with nitrous acid results in diazotization of one amino group followed by immediate cyclization to give benzotriazole (10). 

This copolymer can be obtained from a polydimethylsiloxane that has aminoalkyl end groups in a reaction with the polyetherimide formed from the reaction of a bis(ether anhydride) with diaminobenzene. The material is fire resistant and is used in cable insulations. Among other more complex copolymers with practical applications are poly[2,2-propanebis(4-phenyl)-carbonate]-b/ock-poly(dimethylsiloxane)] and a silicone phenol formaldehyde copolymer obtained in two steps, the first being the heating of a polydimethylsiloxane that has reactive end groups with glycerol, and the second step being the reaction with a phenol formaldehyde resin. 

Conventional condensation of 1,2-diaminobenzene 16 with 6-fluoro-3,4-dihydro-2H-chroman-2-carboxylic acid 17 under Phillips conditions or using Eaton s reagent (1 10 mixture of phosphorus pentoxide/methanesulfonic acid) yielded 2-(6-fluorochroman-2-yl)-lff-benzimidazole 18 (Scheme 4) [30]. However, irradiating the reaction mixture containing polyphosphoric acid as a catalyst with microwaves afforded the compoimd 18 in comparable yields in a matter of three minutes [30]. 

Figure 5.5. Mass spectrum of quinoxaline derivative of 3-hydroxy-2-oxopropanal in wine formed by reaction with 1,2-diaminobenzene. (Reprinted from Journal of Agricultural and Food Chemistry 45, Guillou et al., Occurrence of hydroxypropanedial in certain musts and wines, pp. 3383, 3385, Copyright 1997, with permission from American Chemical Society).

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