2,4-Xylenol, 5-nitro

By using the same molecular proportions the following m-nitrophenols were prepared in equally good yields from the corresponding m-nitroanilincs 3-methoxy-5-nitrophenol and 3-nitro-4,6-xylenol. In the former case it is advisable to use slightly more ice in the diazotization and add the diazonium solution to a mixture of equal volumes of sulfuric acid and water. 

Other methods for nitrates and nitrites include the AOAC procedure in which w-xylenol is nitrated and the nitro-xylenol is distilled into sodium hydroxide solution to form a colored sodium salt that is determined with ultraviolet spectrophotometry at 450 mn. Gas chromatography with electron capture detection and high-performance liquid chromatography have been used for determination of nitrate and nitrite derivatives. 

Hartley DJ. Curran, Polarographic Determination of Nitrates as 4-Nitro-2,6-Xylenol , AnalChem 35, 686-691 (1963) 42) H. 

Nitriles, nitro compounds, sulfur gases, oxides of nitrogen, ammonia and xylenols. 

As regards organic contaminants, leachates from semi-coke contain compounds such as phenols, for example, cresols, resorcinols, and xylenols, which occur at mg/L concentrations. Indeed, Kahru et al. (2002) found total phenols at concentrations up to 380 mg/L in semi-coke dump leachates. Phenols also volatilize from such leachates, depending on temperature and pH (Kundel Liblik 2000). Atmospheric phenol concentrations of 4-50 xg/m3 have been observed in the proximity of leachate ponds (Koel 1999). Generally, aliphatic hydrocarbons, carboxylic acids, and organo-nitro and organo-sulpho compounds do not occur at elevated concentrations in leachates from Estonian semi-coke (Koel 1999). 

Very few physical measurements have been performed on tetrahydronaphthalene with a view to establishing the bond structure of its aromatic ring. The dipole moment measurements on 2,3-dibromo-5,6,7,8-tetrahydronaphthalene [4] have not been interpreted satisfactorily. However, Arnold and Evans [5] have shown that the acidities of 6-nitro- 3,4-xylenol, 6-nitro-5-indanol, and 3-nitro-5,6,7,8-tetrahydro-2-naphthol are virtually the same. Hence, the aromatic bonds in question in all three compounds must have nearly identical double-bond character, thus precluding any appreciable Mills-Nixon effect. 

In the latter part of the nineteenth century new raw materials for the chemical industries became available from city gas and by-product cote oven operations. Benzene, toluene, xylene, naphthalene, phenol, cresols, and xylenols served as crudes for conversion to various intermediates used in the growing new synthetic dyestuff industry. Many of these intermediates and finished products were nitro compounds and found their way into the explosive industry. 

Quite a number of other high explosives were introduced during this period nitro derivatives of aniline, anisole, diphenylamine, cresols, xylenols, etc. Some of these were used as bursting charges and some as boosters, the outstanding representative of the booster explosives being trinitrophenylmethyinitramine (Tetryl). 

Fig. 1 Dependence of the retention factor, k on temperature, T. The solutes are (1) resorcinol, (2) phenol, (3) p-nitro-aniline, (4) o-cresol, (5) nitrobenzene, (6) 2,6-xylenol, (7) 2,4-xylenol, (8) toluene, (9) 2-naphthol, (10) p-propylphenol,...

In a study of mononitro-w-xylcnols, Wheland 24 has found that while m-2-xylenol (LXVII) and m-6-xylenoI (LXVIII) are of about the same acidity, the corresponding para nitro derivatives, LXIX and LXX, dif-... 

Fig. 8.5. Chromatogram of reaction products of 2,4-xylenol with nitrate ion [141]. Peaks 1 solvent 2 = 6-nitro-2,4-xylenoI 3 = 2,4-xylenol.

Conversion of Phenols to Amines. Aniline and some diphenylamine are formed when phenol and NHs solution are heated under pressure in the presence of FeCh, Al(OH)s, or Fe(OH)j. When NH and phenol or ortho-or para-cresols are reacted in the vapor phase over an AljO catalyst, yields of up to 88 per cent of the corresponding amines are obtained. However, these amines are customarily obtained by reducing the parent nitro compound, except in cases where it is difficult to obtain the required nitro isomer. For example, it is considered that the amination of symr xylenol is the best method of preparing sym-xylidine (l-amino-3,5-di-methylbenzene). When sym-xylenol is heated under pressure to 320 C with ammonium chloride, about equal amounts of sj/m-xylidine and sym-dixylylamine (5-imino-bis-l,3-dimethylbenzene) are formed. The ortho-and para-nitrophenols and nitrocresols can be aminat more readily. 2-Nitro-p-cresol [OH(l), N02(2), CHj(4)] and o-nitrophenol have been aminated in aqueous ammonia containing ammonium salts of weak acids to inhibit decomposition. Phosphoric, boric, carbonic, and formic acids were used. In one case it is claimed that 55-65 per cent yields of 2-nitro-p-toluidine (MNPT of commerce) were obtained when 2-nitro-p-cresol, 28 per cent aqueous NHj, and monoammonium phosphate, 1 11.5 0.2 molar ratio, were heated under pressure for 10 hr at 140-150°C and then 5 hr at about 160 C. Earlier workers, employing somewhat similar conditions, claimed excellent yields of MNPT when 1 mole of ammonium formate was used per mole of 2-nitro-p-cresol. ... 

Chromosorb 104 Nitriles, nitro compounds, sulfur gases, ammonia, carbon dioxide, vinyl chloride, moisture in solvents and xylenols. Not recommended for amines and glycols. 

Nitro-o-toluidine 209-366-8 Benzoin ethyl ether 209-388-8 Benzalphthalide 209-400-1 2,6-Xylenol 209-402-2... 

A distillation method for determination of traces of nitrate is of value where it is necessary to remove interfering material. The nitro-derivative of 2,4-xylenol is steam volatile and this compound has been used successfully. ... 

In sulfuric acid and in the presence of nitrogen oxides, phenols give colored indophenols. In the reaction medium they give a blue or green solution, which after dilution with water turns red, and after alkalization becomes blue. A positive reaction is given by phenols with a free para-position, unless they are substituted with —OH, — NH2, — OCH3, — NO2, — CHO, — COOH, or — COCH3. For example, 3,5-xylenol, o-aminophenol, o-nitro-phenol, m-hydroxybenzaldehyde, m-hydroxybenzoic acid, and similar compounds do not react. 

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