3- Bromoaniline

Method 2 (Alkaline hydrolysis). Use a solution of 15 g. of p-bromo-acetanihde in 30 ml. of boiling ethyl alcohol, and add a solution of 7 5 g. of potassium hydroxide in 10 ml. of water. Reflux for 40 minutes, dilute with 120 ml. of water, and distil vmtil 75 ml. of distillate (alcohol and water) are collected pour the residue into 150 ml, of cold water. 

The p-bromoaniline separates as an oil, which soon sohdifies. Filter at the pump and wash with cold water. Purify the crude p-bromoanihne aa follows. Dissolve it in a mixture of 120 ml. of water and 75 ml. of concentrated hydrochloric acid, add 1-2 g. of decolourising carbon, and warm on a water bath for 10 minutes. Filter through a fluted paper or through two thicknesses of filter paper on a Buchner funnel. Pour the filtrate slowly and with vigorous stirring into a mixture of 60 ml. of 10 per cent, sodium hydroxide solution and 100 g. of crushed ice. Thep-bromo-aniline crystallises out. Filter, etc. as in Method 1. The yield is 11 5 g. 

---

Bromoaniline [106-40-1] M 172.0, m 66 , pK 3.86. Crystd (with appreciable loss) from aqueous EtOH. 

After a few minutes 2,4-diamino-6-methylphenol (hRf 5-10), 3-chloro-4-methoxy-aniline (hJ f 25-30), aniline (hRf 35-40), 4-bromoaniline (hRf 40-45), 3-chloroaniline (hJ f 50-55), 2,6-dimethylaniline (hi f 60-65), 2-methyl-6-ethylaniline (hi f 65-70) and 2-chloroaniline (hRj 70-75) yielded orange-colored chromatogram zones on a yellow background. The detection limits were between 5 ng (2,4-diamino-6-methylphenol) and 30 ng (2,6-dimethylaniline) substance per chromatogram zone. 

Fig. 1 Reflectance scans of a chromatogram track with 100 ng each of 1 = 2,4-diamino-6-methylphenol, 2 = 3-chloro-4-methoxyaniline, 3 = aniline, 4 = 4-bromoaniline, 5 = 3-chloro-aniline, 6 = 2,6-dimethylaniline, 7 = 2-methyl-6-ethylaniline and 8 = 2-chloroaniline.

Vasudevan et al. have reported a microwave-promoted hydroami-nation of alkynes. Heating a mixture of l-ethynyl-4-methoxybenzene and 4-bromoaniline in water at 200°C in a microwave reactor for 20 minutes without any catalyst gave an imine product in 87% yield (Eq. 4.45).81... 

See Aniline, 4-Bromoaniline, 2-Chloroaniline, 3-Chloroaniline, 2-Nitroaniline, 3-Nitroaniline, 4-Nitroaniline. 

Chlorobromobenzene has been prepared by the diazotiza-tion of o-bromoaniline followed by replacement of the diazonium group by chlorine 1 by the elimination of the amino group from 3-chloro-4-bromoaniline 2 by the chlorination of bromobenzene in the presence of thallous chloride,3 aluminum chloride,4 or ferric chloride 4 by the bromination of chlorobenzene without a catalyst6 or in the presence of aluminum,4 iron,4 or ferric bromide 6 by the diazotization of o-chloroaniline followed by replacement of the diazonium group with bromine 4,6 and from o-chlorophenylmercurie chloride by the action of bromine.7... 

Materials. Methylene 4,4 -diphenyldiisocyanate (MDI, Mobay) was recrystallized from cyclohexane. Toluenediisocyanate (TDI— represents mixture of 2,4- and 2,6-isomers in 80/20 ratio), p-toluidine (Aldrich) and aniline (Aldrich) were purified by vacuum distillation before use. Diphenylmethane, tert-butyl peroxide (TBP), 4-bromoaniline, butyl lithium in hexane, and ethyl chloroformate, were obtained from Aldrich and used as received. Spectrograde tetrahydrofuran (THF) and benzene from Burdick and Jackson were used as received. Poly(tetramethylene ether glycol) with MW 1000 was obtained from polysciences and dehydrated under a rough vacuum at 50 °C for 24 h. 

Another feature that we may refer to here is that of structural mimicry (52). It is generally accepted that a necessary and sufficient condition for formation of solid-solution crystals by two or more organic substances is similarity of shapes and sizes of the component molecules (53). Consider the two molecules salicylidene-lV-4-chloroaniline and -4-bromoaniline, which are very similar chemically and, in solution, structurally. Both are dimorphic, with molecules... 

Some halo-substituted anilines are of limited thermal stability, tending to eliminate hydrogen halide which may catalyse further decomposition. To avoid decomposition during distillation, this should be conducted in the presence of solid alkali or magnesium oxide at minimum temperature (under relatively high vacuum) and/or with exclusion of air by inert gas. Individually indexed compounds are 4-Bromoaniline, 2296... 

Prenylaniline (945) required for the synthesis of (+ )-carquinostatin A [( )-278] (see retrosynthesis in Scheme 5.126) was obtained by a nickel-mediated cross-coupling reaction of the N-protected 4-bromoaniline 952 with bis[n-bromo(r -prenyl)nickel] (825) (646) (Scheme 5.128). 

A. 4-[(Bromophenyl)azo]morpholine. In a 500-mL Erlenmeyer flask equipped with a magnetic stirring bar are placed 4-bromoaniline (15.0 g, 87 mmol, Note 1) and 6 N hydrochloric acid (HCI), 36.4 mL, 210 mmol) and the mixture is warmed on a water bath to make a clear solution. It is cooled to 0°C to produce a heavy precipitate. A solution of sodium nitrite (6.30 g, 91 mmol) in water (10 mL) is added dropwise over 10 min. Stirring is continued at 0°C for 20 min (Note 2), and morpholine (8.3 g, 9.0 mL, 96 mmol) is added dropwise to the above solution over 10 min. Water (100 mL) is added followed by the... 

Bromoaniline (Lancaster Laboratories), morpholine (Lancaster Laboratories),... 

Bromoaniline, mdls, mp 66°(Ref 3). All of these isomers form numerous salts addn compds, some of which are unstable and even explosive when heated. Other props and methods of prepn are given in the Refs... 

Mononitrobromocmiline, (p2>j)Br.C6H3.NH2 mw 217.91%. Seven isomers are described in the literature 4-Nttro-2-bromo-aniline, yel ndls, mp 104.5 4-Nitro-3 bromoaniline, crysts(from ale), mp 175-6° 2-Nitro-4-bromoaniline, om-yel ndls(from boiling w), mp 111.5° 3-Nitro-4 -bromoaniline, flat ndls (from ale), mp 131° 2-Nitro-5-bromoaniline, red-yel ndls, mp 151-2° 2-Nitro-6-bromoaniline, yel ndls(from dil ale), mp 73-5° and 3-Nitro-6-bromoaniline, yel ndls (from ale), mp 141°. Some of these isomers form salts addn compds, some of which are volatile and unstable. 

---