Nitration xylenes

Derivation By nitrating xylene and separating from the resulting mixture by rectification. 

Unlike o-xylene and p-xylene, the application of m-xylene is limited to the production of isophthalic acid, nitrated xylenes and m-xylylenediamine. Production of 3,5-dimethylphenol, which was carried out in earlier times by alkali fusion, has now been replaced by gas-phase aromatization of isophorone (see Chapter 53.4.3.2). 

Zeroth-order nitrations. The rates of nitration at 25 °C in solutions of acetyl nitrate (6xio —0-22 mol 1 ) in acetic anhydride of 0- and jw-xylene, and anisole and mesitylene were independent of the concentration and nature of the aromatic compound provided that... 

Acetoxylation and nitration. It has already been mentioned that 0- and m-xylene are acetoxylated as well as nitrated by solutions of acetyl nitrate in acetic anhydride. This occurs with some other homologues of benzene, and with methyl phenethyl ether,ii but not with anisole, mesitylene or naphthalene. Results are given in table 5.4. 

The addition of sulphuric acid increased the rate of nitration of benzene, and under the influence of this additive the rate became proportional to the first powers of the concentrations of aromatic, acetyl nitrate and sulphuric acid. Sulphuric acid markedly catalysed the zeroth-order nitration and acetoxylation of o-xylene without affecting the kinetic form of the reaction. ... 

In the nitration and acetoxylation of o-xylene the addition of acetic acid increased the rate in proportion to its concentration, the presence of 3-0 mol 1" accelerating the rate by a factor of 30. In the presence of a substantial concentration (2-2 mol 1 ) of acetic acid the rate of reaction obeyed the following kinetic expression... 

If acetoxylation were a conventional electrophilic substitution it is hard to understand why it is not more generally observed in nitration in acetic anhydride. The acetoxylating species is supposed to be very much more selective than the nitrating species, and therefore compared with the situation in (say) toluene in which the ratio of acetoxylation to nitration is small, the introduction of activating substituents into the aromatic nucleus should lead to an increase in the importance of acetoxylation relative to nitration. This is, in fact, observed in the limited range of the alkylbenzenes, although the apparently severe steric requirement of the acetoxylation species is a complicating feature. The failure to observe acetoxylation in the reactions of compounds more reactive than 2-xylene has been attributed to the incursion of another mechan-104... 

Nitration of 1 4 dimethylbenzene (p-xylene) gives a single prod uct having the molecular formula C8H9NO2 m high yield What is this product... 

Nitration of m xylene is directed ortho to one methyl group and para to the other... 

Chemical Properties and Reactivity. LLDPE is a saturated branched hydrocarbon. The most reactive parts of LLDPE molecules are the tertiary CH bonds in branches and the double bonds at chain ends. Although LLDPE is nonreactive with both inorganic and organic acids, it can form sulfo-compounds in concentrated solutions of H2SO4 (>70%) at elevated temperatures and can also be nitrated with concentrated HNO. LLDPE is also stable in alkaline and salt solutions. At room temperature, LLDPE resins are not soluble in any known solvent (except for those fractions with the highest branching contents) at temperatures above 80—100°C, however, the resins can be dissolved in various aromatic, aUphatic, and halogenated hydrocarbons such as xylenes, tetralin, decalin, and chlorobenzenes. 

Petrochemicals are those chemicals produced from petroleum or natural gas and can be generally divided into three groups (/) aliphatics, such as butane and butene (2) cycloaliphatics, such as cyclohexane, cyclohexane derivatives, and aromatics (eg, ben2ene, toluene, xylene, and naphthalene) and (J) inorganics, such as sulfur, ammonia, ammonium sulfate, ammonium nitrate, and nitric acid. 

Approximately 45% of the world s phthaUc anhydride production is by partial oxidation of 0-xylene or naphthalene ia tubular fixed-bed reactors. Approximately 15,000 tubes of 25-mm dia would be used ia a 31,000 t/yr reactor. Nitrate salts at 375—410°C are circulated from steam generators to maintain reaction temperatures. The resultant steam can be used for gas compression and distillation as one step ia reduciag process energy requirements (100). 

Rapid, simple, quaUtative methods suitable for determining the presence of benzene in the workplace or surroundings have been utilized since the 1930s. Many early tests offered methods for detection of aromatics but were not specific for benzene. A straightforward test allowing selective detection of benzene involves nitration of a sample to y -dinitrobenzene and reaction of the resultant ether extract with an ethanoHc solution of sodium hydroxide and methyl ethyl ketone (2-butanone), followed by the addition of acetic acid to eliminate interferences from toluene and xylenes. Benzene imparts a persistent red color to the solution (87). The method is claimed to be sensitive to concentrations as low as 0.27 ppm benzene from 10 mL air samples. 

Cyclohexanoae is miscible with methanol, ethanol, acetone, benzene, / -hexane, nitrobenzene, diethyl ether, naphtha, xylene, ethylene glycol, isoamyl acetate, diethylamine, and most organic solvents. This ketone dissolves cellulose nitrate, acetate, and ethers, vinyl resias, raw mbber, waxes, fats, shellac, basic dyes, oils, latex, bitumea, kaure, elemi, and many other organic compounds. 

Tnflic acid is an excellent catalyst for the nitration of aromatic compounds [.S7]. In a mixture with nitnc acid, it forms the highly electrophilic nitronium inflate, which can be isolated as a white crystalline solid Nitronium inflate is a powerful nitrating reagent in inert organie solvents and in tnflic acid or sulfuric acid. It nitrates benzene, toluene, chlorobenzene, nitrobenzene, m-xylene, and benzotn-fluoride quantitatively in the temperature range of-110 to 30 °C with exeeptionally high positional selectivity [87],... 

Hydroxyethylation of 2,6-dimethylquinoline with ethylene oxide in presence of Li in PhBr gave 104 which was hydrogenated to the tetrahydro derivative 105. Its cyclization with P205/xylene gave the pyrroloquinoline 106. Nitration of 106 with fuming HNO3/H2SO4 afforded a mixture... 

The mono- and dinitro products have no musk odour, and therefore the nitration of the hydrocarbon should be carried as far as possible. The constitution of this artificial musk, or " xylene musk as it is often called, is probablv—... 

Sodium Chloride [25]. Sodium chloride estimation is based on sodium titration. To 20 ml of a 1 1 mixture of toluene (xylene) isopropyl alcohol, add a 1-ml sample of oil-base mud, stirring constantly and 75 to 100 ml of distilled water. Add 8-10 drops of phenolphthalein indicator solution and titrate the mixture with H SO (N/10) until the red (pink) color, if any, disappears. Add 1 ml of potassium chromate to the mixture and titrate with 0.282N AgNO (silver nitrate, 1 ml = 0.001 g chloride ions) until the water portion color changes from yellow to orange. Then... 

OB to C02 —85.04%, needles from glac AcOH, mp 262—63° (decomp). Sol in glac AcOH, acet, dioxane py si sol in benz, toluene, xylene amyl ale. Prepn from l-nitro-2-. me thy lnaphthalene by nitration using mixed acids of nitric (d 1.52g/cc), sulfuric (d 1.84 g/cc) oleum (20—25% SO5 free), and heating for one hour at 80° on a water bath. Two other isomers which do not decompose are prepd simultaneously viz, mp (I) 230° ... 

Solvent Naphtha (160° benzol). A mixt of small percentages of benzene and toluene with xylene and higher homologs from coal tar. In crude form, a dark straw-colored liq, bp about 160° (80%), d 0.862—0.892g/cc, flash p about 78°F. When refined, a w-white liq, bp about 160° (90%), d 0.862-0.872g/cc, flash p about 78°F. May be obtained from coal tar by fractional distillation. When nitrated, used in Dynamites (Ref 5)... 

---