4- Nitroacetanilide

Add 25 g. of finely-powdered, dry acetanilide to 25 ml. of glacial acetic acid contained in a 500 ml. beaker introduce into the well-stirred mixture 92 g. (50 ml.) of concentrated sulphuric acid. The mixture becomes warm and a clear solution results. Surround the beaker with a freezing mixture of ice and salt, and stir the solution mechanically. Support a separatory funnel, containing a cold mixture of 15 -5 g. (11 ml.) of concentrated nitric acid and 12 -5 g. (7 ml.) of concentrated sulphuric acid, over the beaker. When the temperature of the solution falls to 0-2°, run in the acid mixture gradually while the temperature is maintained below 10°. After all the mixed acid has been added, remove the beaker from the freezing mixture, and allow it to stand at room temperature for 1 hour. Pour the reaction mixture on to 250 g. of crushed ice (or into 500 ml. of cold water), whereby the crude nitroacetanilide is at once precipitated. Allow to stand for 15 minutes, filter with suction on a Buchner funnel, wash it thoroughly with cold water until free from acids (test the wash water), and drain well. Recrystallise the pale yellow product from alcohol or methylated spirit (see Section IV,12 for experimental details), filter at the pump, wash with a httle cold alcohol, and dry in the air upon filter paper. [The yellow o-nitroacetanihde remains in the filtrate.] The yield of p-nitroacetanihde, a colourless crystalline sohd of m.p. 214°, is 20 g. 

Add 25 g. of finely-powdered, dry acetanilide to 25 ml. of glacial acetic acid contained in a 600 ml. beaker introduce into the well-stirred mixture 92 g. (50 ml.) of concentrated sulphuric acid. The mixture becomes warm and a clear solution results. Surround the beaker with a freezing mixture of ice and salt, and stir the solution mechanically. Support a separatory funnel, containing a cold mixtme of 15-5 g. (11 ml.) of concentrated nitric acid and 12 5 g. (7 ml.) of concentrated sulphuric acid, over the beaker. When the temperature of the solution falls to 

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Prepared by heating p-nitrochlorobenzene with concentrated aqueous ammonia in an autoclave at 170°C. It is also prepared by alkaline hydrolysis of p-nitroacetanilide or by nitrating and hydrolysing benzylideneaniline. 

Recrystallise the crude pale yellow product from methylated spirit, filter at the pump, wash quickly with a few ml. of fresh spirit, and then drain and dry. The yellow o-nitroacetaniiide remains in the filtrate, whilst the p nitroacetanilide is obtained as colourless ciy stals, m.p. 214°. A second recrystallisation of the para compound should not be necessary. Yield of pure product, 8 g. 

Heat a mixture of 15 g. of p-nitroacetanilide and 75 ml. of 70 per cent, sulphuric acid (1) under a reflux water condenser for 20-30 minutes or until a test sample remains clear upon dilution with 2-3 times its volume of water. The p-nitroaniline is now present in the hquid as the sulphate. Pour the clear hot solution into 500 ml. of cold water and precipitate the p-nitroanihne by adding excess of 10 per cent, sodium hydroxide solution or of concentrated ammonia solution. When cold (cool the mixture in ice water, if necessary), filter the yellow crystalline precipitate at the pump, wash it well with water, and drain thoroughly. Recrystallise it from a mixture of equal volumes of rectified (or methylated) spirit and water or from hot water. Filter, wash and dry. The yield of p-nitroanihne, m.p, 148°, is 11 g. 

Compounds containing two primary amino groups attached to a benzene ring can be prepared by the reduction of dinitro compounds and of nitroanilines, usually with tin or stannous chloride and hydrochloric acid or with iron and very dilute hydrochloric acid. / ara-diamines may also be obtained by the reduction of aromatic amino-azo compounds (e.g., p-aminodimethylanihne from methyl orange, see Section IV,78). p-Phenylenediamine may also be prepared from p-nitroacetanilide reduction with iron and acid yields p-amino-acetaniUde,.which may be hydrolysed to the diamine. 

A mixture of 6.65 g of 3-chloro-6-nitroacetanilide, 3.2 ml of propylmercaptan, 5.6 g of 50% sodium hydroxide and 100 mi of water Is heated at reflux overnight. The cooled mixture is filtered to give the desired 2-nitro-5-propyithioaniline, MP 69.5°-71.5°C after recrystailiza-tion from ethanoi then hexane-ether. NMR (CDCi3) 40%. 

The Na salt of MEDINA was fluorinated in w, the sain extd with methylene chloride, and the solv evapd to give a yellow oil whose IR spectrum showed absence of NH and the presence of NF absorption, and analysis indicated was a mixt (Ref 22). Nitramines in the presence of sulfuric acid are capable of nitrating reactive aromatic compds, but when acetanilide was treated with MEDINA in the presence of this acid, no nitroacetanilide was isolated. Instead compds indicating that the MEDINA had been fragmented and the fragments reacted with the acetanilide were isolated (Ref 12)... 

De la Mare and Hassan254 obtained second-order rate coefficients (in parenthesis) for the following 4-methylacetanilide (1.53), 2-methylacetanilide (0.193), 2,6-dimethylacetanilide (0.0118), acetanilide (0.93), 4-acetamidodiphenyl (0.248) and 1,4-diacetamidobenzene (0.231) the results for the acetanilides demonstrated the effect of steric hindrance to coplanarity thereby inhibiting resonance of the nitrogen lone pair with the aromatic ring. The rate coefficients for chlorination of 3-chloroacetanilide (0.215), 4-chloroacetanilide (0.010) 3-nitroacetanilide (6.7 x 10 5) and phenyl benzoate (3.2 x 10-6) have also been measured258,261. 

It seems that NCS should be involved in free radical reaction generated by NBS. But, the presence of traces of 4 also indicative of the production method unless extremely pure NBS has been used for bromination. Instantly, for the regular preparation of 4 the method with N,2,6-trichloro-4-nitroacetanilide is more successful (ref. 2). 

FIGURE 13 Cumulative release of -nitroacetanilide (PNAC) from polyester discs prepai ed from 3,9-bis(ethylidene-2,4,8,10-tetraoxas-piro[5,5]undecane) and a 60 10 30 mole ratio of trans-cyclohexane dimethanol, 1,6-hexanediol, and triethylene glycol at pH 7.4 and 37 C. PNAC content 2 wt% (o) 0 mol%, ( ) 0.25 mol%, ( ) 0.50 mol% 9,10-dihydroxystearic acid. (From Ref. 23.)... 

When p-nitroacetanilide is heated to 200-250 C in the presence of small quantities of sulphuric acid, it gives rise to a very spectacular decomposition and the formation of a huge quantity of carbonised foam . This extraordinary reaction is called black snake . 

P(0)(0Me)H and [TpAr Me]Zn0P(0)(0R)2, respectively (Scheme 26) (35). In addition, [TpAr Me]ZnOH also cleaves activated esters and amides in a stoichiometric fashion, as illustrated in Scheme 27. Kitajima has described a similar amide cleavage reaction between the copper and nickel hydroxide complexes [Tp JMtOH) (M = Ni, Cu) and p-nitroacetanilide to give [TpPr 2]M p2-MeC(0)NC6H4N02 [Eq. (34)] (198). 

C42H70O35 CgH8N203 x H20 Cyclomaltoheptaose - 4 -nitroacetanilide, hydrate CHANAO 43 372... 

The procedure described for the preparation of l-(m-nitro-phenyl)-3,3-dimethyltriazene is the method of Elks and Hey,2 and the preparation of m-nitrobiphenyl is also a modification of their procedure. The other principal methods for the preparation of m-nitrobiphenyl are the decomposition of N-nitroso-w-nitroacetanilide in benzene 3 and the decomposition of alkaline m-nitrobenzenediazohydroxide in benzene.4 Other methods that have been reported include the decomposition of potassium ire-nitrobenzenediazotate in benzene with acetyl chloride,6 the decomposition of m-nitrobenzoyl peroxide in boiling benzene,6 the decomposition of benzenediazonium borofluoride in nitrobenzene 7 at 70°, and the reduction of 4-(3 -nitrophenyl)-benzenediazonium acid sulfate in boiling ethanol.8... 

Nitroaniline reacts almost explosively [1], and 4-nitroaniline, 4-nitroacetanilide, aminonitrobiphenyls, aminonitronaphthalenes and their various derivatives [2], as well as some nitro-N-heterocycles [1,2], also react vigorously. 4-Nitroanilinium sulfate and 4-nitroaniline-2-sulfonic acid and its salts also generate foams when heated without sulfuric acid. The mechanism is not clear, but involves generation of a polymeric matrix foamed by sulfur dioxide and water eliminated during the reaction [1]... 

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