Bromo aniline

Add 20 g. of /)-bromoaniline to 20 ml. of water in a 250 ml. beaker, and warm the mixture until the amine melts. Now add 23 ml. of concentrated hydrochloric acid and without delay stir the mixture mechanically in an ice-water bath, so that a paste of fine /> bromo-aniline hydrochloride crystals separates. Maintain the temperature of the stirred mixture at about 5° whilst slowly adding from a dropping-funnel a solution of 8 5 g. of sodium nitrite in 20 ml. of water con tinue the stirring for 20 minutes after the complete addition of the nitrite. 

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. 

Benzaldehyde, 4-(l,l-dimethylethyl)- [Benzaldehyde, 4-rerf-butyl-], 55, 10 Benzaldehyde, 4 (1-methylethyl- [Benzaldehyde, 4 isopropyl ], 55, 10 Benzenamine, 2-bromo- [Aniline, 2 bromo ], p-bronnnation of, 55, 23 Benzenamine, 3-bromo- [Aniline, 3-bromo-], p-bromination of, 55, 23 BENZENAMINE, 4-bromo-yV,V-dimethyl-... 

Aluminum chloride-phosphorus oxychloride complex, 31, 88 Amberlite IR-4B resin, 32, 13 Amidation, of isocyanic acid with bromo-aniline and other aromatic amines, 31,8... 

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. 

Alkoxy derivatives of biphenyl can be obtained either from alkoxy-anilines or by coupling with alkoxybenzenes. From diazotized p-bromo-aniline and anisole a 20% yield of 4-bromo-2 -methoxybiphenyl and a 7% yield of 4-bromo-4 -methoxybiphenyl are obtained. In connection with their studies on Cannabis Indica, Ghosh, Pascall, and Todd u prepared the highly substituted biphenyl compound, 2-cyano-5-methyl-2, 5 -dimethoxy-4 -n-amylbiphenyl (VII), in 27% yield from the nitrosoacetyl derivative of 2-cyano-5-methylaniline and 2,5-dimethoxy-n-amylben-zene. 

Di-isopropyl 4 bromo aniline diafenthiuron Diisopropyl phosphorochloroido thioate see DIPCT Diketal sorbose dikegulac-sodium... 

The phototransformation of aqueous 2-chloroaniline was studied by Oth-men and Boule by means of product analysis [47] these authors later deepened and extended their work, including also 2-fluoro- and 2-bromo-aniline [48]. The range of photodegradation quantum yields was

[Pg.172]

N-saltcylidene 2-chloro-aniline (2-CI, X=H,Y=Cl). N-salicylidene 2-bromo-aniline (2-Br, X=H,Y=Br), N-salicylidene 4-bromo-aniline (4-Br, X=Br, Y=H), and N-salicylidene 2-methyl-4-nitro-aniline (2-Me-4-N02,X=N02,Y=CH3). ... 

Somewhat similar methods are used in the preparation of bromo-anilines. Consider, for example, the preparation of p-bromoaniline. The action of bromine on aniline gives quantitatively 2, 4, 6-tribro-moaniline. If aniline is first acetylated and then brominated, ortho-and poro-bromoacetanilides are formed with the para isomer predominating. The ortho compound is more soluble in alcohol than the para isomer, and thus can be removed by crystallization. The p-bromoacetanilide is then hydrolyzed. A variation of this method is to add bromine very slowly to aniline dissolved in a large excess of glacial acetic acid, when p-bromoaniline is directly formed, thereby eliminating acylation and hydrolysis. 

In 1968 Porter and Ward [87] studied the gas phase flash photolysis of ortho-chloro aniline, ortho-bromo aniline and phenyl isocyanate and observed a strong new transient absorption with a half-life of ss 100 /is. A series of well resolved vibrational bands were observed between 370.629 and 345.310 nm. The most intense band was observed at 368.307 nm. Porter attributed this band system to triplet phenyl nitrene. The nitrene can of course be easily formed from phenyl isocyanate by extrusion of carbon monoxide. 

There are many variations, and a wide range of aromatic diazonium salts can be used. One method for generating the diazonium salt is treatment of an aromatic amine with nitrous acid (HONO via reaction of HNO3/HCI or NaN02/2 HCl).i62 These diazonium salts can be coupled to other aromatic compounds in the presence of base in what is commonly called the Gomberg-Bachmann reaction. 63 Treatment of 4-bromo-aniline with nitrous acid, for example, gave the diazonium salt (231) which reacted with benzene to give the... 

Rearrangement occurs during the palladium-catalysed cyclization of a-substituted-N-acryloyl-o-bromo-anilines (129), and 4-substituted, e.g. (130), rather than 3-substituted quinolones are obtained (Scheme 53). ... 

Derkach and Liptuga ( ) demonstrated the stepwise mechanism leading to carbodiimides by treating phosphorylcarbonimidoyl dichloride (CXI) with a deficient amount of arylamines, such as aniline and p-bromo-aniline. The elimination of hydrogen chloride from the intermediate CXII occurs in diethylether at room temperature, using triethylamine as the hydrogen chloride scavenger. 

---