Dibromo-aniline

DICHLOROANILINE AND 2,6-DIBROMO ANILINE (Aniline, 2,6-dichloro- and 2,6-dibromo-)... 

Ridd and coworkers71 have now shown unequivocally that radical pairs are indeed involved in this rearrangement by observation of strong enhancement of 15N NMR signals in both the reactant and product, when reaction was carried out with 15N-labelled nitro groups in both A-methyl-A-nitroaniline and also in A-methyl-A-nitro-2,5-dichloro (and dibromo) aniline. 

Dibromo-2,7-diaminoantbraquinone, bm crysts (from aniline) sol in common org solvs insol in w 8t alkalies [Ref, p (473)]... 

Quinoxaline-2,3-dione is converted into 2,3-dichloroquinoxaline by phosphoryl chloride142 or phosphorus pentachloride.143 2,3-Dibromo-quinoxaline is similarly obtained using phosphoryl bromide in dimethyl-aniline.144 Quinoxalin-2-one undergoes ring contraction to 2-methyl-benzimidazole (134) with hydrazine145 however, quinoxaline-2,3-dione gives 3-hydrazino-2-quinoxalinone.145 Quinoxalin-2-one yields a 3-p-dimethylaminophenyl derivative with 7V,N-dimethylaniline (in AcOH, with NH4N03), and a 3-(indol-3-yl) derivative with indole.146... 

Other suitable diazo components are 4-nitroaniline (orange), 2,6-dichloro-4-(N,N-dimethylsulfamoy 1 )ani 1 ine (orange), 4-aminobenzophenone (yellow), 2,4,6-trichloro aniline (yellow), 2,4,6-tribromoaniline (yellow), 2,6-dibromo-4- nitro aniline (yellow-brown) [30], and 2-cyano-5- chloroaniline (orange). 

Aromatic primary monoamine such as aniline serves as a difunctional monomer for Pd-catalyzed amination polycondensation to afford poly(triarylamine)s. For example, m-dibromobenzene [71] or 2,7-dibromo-fluorenes [72] reacted with aniline derivatives (Scheme 16). In these polymerizations, P(f-butyl)3 was an effective ligand of Pd2(dba)3 in a manner similar to the amination of aryl dibromides with secondary diamines. The Mw values were in the range of 9000-37 700. 

CH orn prisms (from chlf + petr eth), mp 91-92° was obtd by treating an acetic acid soln of 4,6-dibromo-2-nitro-aniline with HNO3, followed by addn of acetic anhydride in the cold. A Barium salt,... 

A similar tetramethyl derivative was obtained as adduct by electrolysis of 2,4-dibromo-2,4-dimethylpentan-3-one (18) in methanol in the presence of aniline. The formation of adduct 20 might be explained by addition of methanol to the electrosynthesized tetramethylcyclo-propylideneamine 19. 

A simple acid-catalyzed condensation in methanol such as for 2,6-diisopropyl-aniline yielded no product. Another difference in behavior between this diimine and the one based upon 2,6-diisopropylaniline is observed in the reaction with (COD)PdCl2 or (COD)PdMeCl 2,3-bis(2,6-dibromo-4-methylphenyl)imine butane is inert toward these palladium catalyst precursors, whereas the alkyl-substituted... 

Fig. 3.4 Steric extension of 2,6-dibromo- (left), 2,6-diisopropyl-aniline (right) and overlay, front and side views.

Jy/ .-tribromobenzene has been prepared from 3,5-dibromo-aniline by the replacement of the amino group by bromine from bromoacetylene by the action of light by the decomposition of 2,4,6-tribromophenylhydrazine by the reduction of 2,4,6-tri-bromobenzene diazonium sulfate and as a by-product in the preparation of 2,4,6-tribromobenzonitrile. ... 

N-Tosyl-substituted amines have also been used to prepare secondary diamino ethers. Petranek and Ryba (1980) reacted yV-tosylbenzylamine or the aniline analog with the dibromo derivative of dicthylene glycol to form the bis(A -tosylamino) derivatives. The tosyl blocking groups were removed by... 

Dianllinoethane. N,N -Diphenyl-1,2-ethane-diamine IV.N -diphenylethylettediamine Ttf./V -diphenyl-ti.u-dLaminoethane spin-diphen Viet hylenediamine. C Hl(-Np mol wt 212.28. C 79.217. H 7.60%, N 13.207. Prepd by heating aniline with dichloroethane Biichi et at, Heiv. Chim. Acta 39, 950 (1956) by heating aniline with dibromo-ethane Wanzlick, Lochel, Ber. 86, 1463 (1953). 

Chlorination or bromination of both ortho-positions of aniline can be achieved by a device similar to that used for phenol the para-position is substituted by a group that can be removed later. The preparation of 2,6-dichloro- and 2,6-dibromo-aniline can be cited as examples that also illustrate halogenation by HC1 or HBr and H202 (for older papers see Leulier496 and Zinke497) ... 

When o- or /7-hydroxy (or amino)benzaldehyde is titrated with bromine in aqueous solution at 40-45° 2,4,6-tribromophenol or -aniline is obtained almost quantitatively the aldehyde group is not oxidized to carboxyl but replaced by bromine it is eliminated as carbon monoxide which originates from decomposition of formyl bromide that is formed as intermediate.65 At 10° and 15°, respectively, these hydroxy and amino aldehydes are, however, merely converted into the dibromo aldehydes with retention of the CHO group, e.g. ... 

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