Bromo 4-amino toluene

Bromo-4-aminotoluene, Suspend the hydrochloride in 400 ml, of water in a 1-Utre beaker equipped with a mechanical stirrer. Add a solution of 70 g. of sodium hydroxide in 350 ml. of water. The free base separates as a dark heavy oil. After cooUng to 15-20°, transfer the mixture to a separatory funnel and run off the crude 3-bromo-4-amino-toluene. This weighs 125 g. and can be used directly in the next step (3). 

After the addition of 2 1. of water, the mixture is steam-distilled as long as any oil comes over. The crude, heavy, yellow oil is separated and washed with two 200-cc. portions of 10 per cent sodium hydroxide, once with 100 cc. of water, twice with 150-cc. portions of concentrated sulfuric acid, and finally with 100 cc. of 5 per cent, sodium carbonate solution. It is dried with about 5 g. of calcium chloride, filtered through glass wool, and distilled using a long air condenser. Most of the product boils at i8o-i83°/75o mm. The yield of pure colorless material, b.p. i83°/76o mm., is 125-135 g. (36-39 per cent of the theoretical amount, based on the amount of -toluidine originally used, or 54-59 per cent based on the amount of 3-bromo-4-amino-toluene). 

In a 2-1. beaker is placed 75 g. (0.4 mole) of 3-bromo-4-amino-toluene (Note 1), and to it is added the hot diluted acid obtained by adding 72 cc. of concentrated sulfuric acid to 200 cc. of water. The clear solution is stirred and cooled to about 15°, after which 180 g. of ice is added the amine sulfate usually separates. As soon as the temperature has dropped below +5°, a solution of 32.2 g. (0.47 mole) of sodium nitrite in 88 cc. of water is added from a dropping funnel, the stem of which extends below the surface of the liquid. The temperature of the solution is kept below +5° during the addition, which requires about fifteen minutes. The solution is stirred for five minutes after the addition of all the sodium nitrite, and 300 g. of cold water, 3 g. of urea, and 300 g. of cracked ice are then added successively. The solution is kept in an ice bath until used. 

Some idea of the utility of the hydrazine procedure may be inferred from the yields obtained on deaminating the following compounds aniline (45-75%),110 1Ui 118 p-toluidine (55-65%),uo 116 3-chloro-4-amino-toluene (40%),117 5-bromo-6-aminoquinoline ( satisfactory yield ).181 ... 

Sodium 3-aminothiophene-2-carboxylates were reacted with EMME in boiling toluene in the presence of acetic acid for 4-6 hr to give 3-thienylaminomethylenemalonates (58) in moderate yields (87T3295 88EUP269295). The 5-bromo derivative of compound 58 (R = Br) was prepared in the reaction of 3-amino-5-bromothiophene and EMME, but 2-amino-5-nitrothiophene failed to react (87T3295). 

Bromo-3-methoxycarbonylpyrazine with 2,3-dimethylaniline in refluxing toluene gave 2-(2, 3 -dimethylphenyl)amino-3-methoxycarbonylpyrazine (950) [hydrolysis of this product with sodium hydroxide in ethanol gave 2-carboxy-3-(2, 3 -dimethylphenyl)aminopyrazine, which was also obtained by treatment of l-(2, 3 -dimethylphenyl)lumazine with sodium hydroxide in refluxing ethanol (950)]. 3-Bromo-2-hydroxy-5-phenylpyrazine with ammonium hydroxide and copper at 150° gave 3-amino-2-hydroxy-5-phenylpyrazine (365a). Replacement of the iodo substituent from 2-amino-5-iodo-3,6-dimethylpyrazine has been effected with ammonium hydroxide (887). 

Benzyl bromide Toluene, a-bromo- (8) Benzene, (bromomethyl)- (9) (100-39-0) (S)-2-(N,N-Dlbenzylamino)-3-phenyl-1-propanol Benzenepropanol, p-[bis(phenylmethyl)amino]-, (S)- (12) (111060-52-7)... 

Examples of toxic compounds, including some important intermediates and starting materials in the chemical industry, are shown in Figure 3.3. Many alkali fluorides, such as alkali hexafluorosilicate, alkali hydrogen difluoride, or alkali sulfuryl fluoride, are well known toxic substances. Sulfur dioxide and ammonia (ubiquitous gases) are toxic, as are chlorine, metallic mercury vapors, many organic phenol compounds, amino aromatic compounds such as aniline, and many substituted amino-benzene derivatives. Additionally, many diisocyanates are toxic, e.g., 2,4- and 2,6-toluene diisocyanate (TDI), hexamethylene diisocyanate (HDI), chloro-, bromo-, and iodoacetic acid, methyl bromide, tribromomethane (bromoform), carbon tetrachloride, and formaldehyde. Also, many natural compounds present in many plants have toxic properties, and a selection of these are listed in Table 3.4. 

Protection and Deprotection.—N-Protected a-amino-acids are readily esterified by methanol or ethanol in 60—80% yield after reaction with an enamine (e.g. from isobutyraldehyde and piperidine) and t-butyl isocyanate. Such amino-acids can also be esterified efficiently with alkyl halides under phase-transfer conditions with no racemization. Direct esterification of a-amino-acids with ethyl toluene-p-sulphonate in boiling ethanol gives a-amino-acid ethyl esters in 80—90% yield as the sulphonate salts. The protection of acid functions by formation of the 2-chloro-(or bromo-)ethyl esters has been discussed. These derivatives survive exposure to both moderately acidic and basic conditions and are removable by conversion into the iodoethyl analogues followed by zinc reduction. Alternatively, they may be converted into hydrophilic ammonium or phosphonium salts which exhibit enhanced acid stability but which are cleaved by very dilute base. Yet another method for the removal of such groups using supernucleophilic Co phthalocyanin anions has been reviewed. Further routes to 2,2,2-trichloroethyl esters have been described, one of which employs an activated ester intermediate and is suited to acid-labile substrates. 

The rates of displacement of the sulphonate group by azide ion in DMF at 110 °C have been measured for a series of toluene-p-sulphonyl and p-bromo-benzenesulphonyl derivatives of 3-0-methyl-cA/ra-inositol and 4-0-methyl-tf//< -inositol in these compounds, the arylsulphonate group was located at position 4 (or 3), and the substituents at positions 1,2, 5, and 6 were isopropylidene, acetyl, methyl, and cyclic carbonate. All of the resulting azides (except the unreactive penta-O-methyl-c/j/ra derivative) could be converted into one of two inosamine penta-acetates, viz. lL-2-amino-2-deoxy-l-0-methyl-a//o-inositol and 1d-3-amino-3-deoxy-4-0-methyl-c/ /ra-inositol penta-acetates. The results were discussed in terms of currently held views on displacement reactions with carbohydrate and related sulphonates. 

This p. is based on - undecylenic acid, which derives from - castor oil and represents a p. of type II. Undecylenic acid is reacted with HBr in the presence of peroxides or air in, e.g., toluene at 30°C. 11-Bromo-undecanoic acid is formed in over 95% yield. Further reaction with 25% aqueous ammonia gives the desired 11-amino-undecanoic acid. Repeated crystallization enhances the pinity of the monomer. The polycondensation is carried out in a column with three zones melting, main reaction and equilibration of m.w. Phosphorous and phosphoric acids and their salts act as catalysts. The resulting p. (m.p. 190 °C) is very hydrophobic, has a low moisture content and is therefore used in electrical insulation. Other applications are as filament, powder - coatings and - molded goods. Castor oil consumption for this area was 35000 mt (1988). 

A soln. of NaNOg in DgO added slowly at ca. 0° to a mixture of 2-bromo-3-amino-dg-toluene, deuteriohypophosphorous acid, and DgO, stirred during Ng-evolution, and kept overnight in a refrigerator 2-bromotoluene-3-d. Y 55 to 59%. Also replacement by hydrogen in 50%-hypophosphorous acid s. R, N. Renaud, D. Kovachic, and L. G. Leitch, Gan. J. Ghem. 39, 21 (1961). 

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