CS270521B1 - Process for producing 3-methyl-4-nitrosophenol - Google Patents

Abstract

3-Methyl-4-nitrosophenol is produced by nitrosation of 3-methylphenol with sodium nitrite in a mineral acid environment in the presence of a surfactant.

Description

CS 270521 B1

The invention relates to a process for the preparation of 3-methyl-4-nitrosophenol by nitroso-3-methylphenol with a solution of sodium nitrite in an environment of mineral acid in the presence of surfactant 3-methyl-4-nitrosophenol is most frequently used as an intermediate in the production of 3-methylphenol nitroderates . The preparation of 3-methyl-4-nitroso-ethanol is described by Bridge Morgan, J. Am. Soc. 20,766 (1898) nitroso-3-methylphenol with nitrous acid. The nitrosation of 3-methylphenol with alkali nitrite in sulfuric acid is described in U.S. Pat. The solubility of 3-methylphenol in aqueous mineral acid solutions is low and the reaction proceeds to virtually interfacial vapors of the organic layer and aqueous solutions. 3-Methyl-4-nitrazophenol is very poorly soluble in the reaction mixture. On an industrial scale, it is often the case that incrustations are formed on the reactor walls, stirrers, etc., while the 3-methylphenol moieties remain unreacted and the encrustations themselves reduce heat transfer through the reactor core, and local overheating of the reaction mixture may occur.

The aforementioned drawbacks are alleviated by the process for the preparation of 3-methyl-4-nitrosophenol, wherein 3-methylphenol is nitrosated with an aqueous solution of sodium nitrite in the presence of a mineral acid, most commonly sulfuric acid or hydrochloric acid.

Nitrosation occurs in the presence of a surfactant. An advantage of the process according to the invention is that in the production of 3-methyl-4-nitrosophenol there are no incrustations on the walls of the reaction apparatus which impair the heat transfer, thereby causing local overheating. After the production of 3-methyl-4-nitrosophenol has been completed, the incrustation must be removed. The surfactant provides better contact between the organic and inorganic portions of the liquid phase and the reaction can take place in part in the emulsion, which allows the poultry reaction rate to be better than heat dissipation. Example 1

340 g of 60.3% by weight were added to the reaction flask. sulfuric acid and 35 g of 3-methylphenol and 2 mg of ethylene oxide oxidation adduct of nanoic acid with ethylene oxide print 19 to 24 (SlovaeolBL). The mixture was cooled to 0 ° C with stirring. Then, 70 g of 38 wt. NaNO 3 aqueous solution. After washing, the suspension was filtered and washed with 100 mL of water. The 44.3 g filter cake contained 99 wt. 3-methyl-4-nitrosophenol. Example 2

1,220 l of 60-, 3 wt. sulfuric acid, which was cooled to 5 ° C. Then 183 l of 3-methylphenol and 0.02 l of 20 wt. aqueous sodium dodecylbenzanesulfonate solution (Abeson NAM). Then, after cooling to 0 ° C, a weight of 300 wt. aqueous sodium nitrite solution while the temperature does not exceed 5 ° C. The dosing time was 160 min. The reaction mixture was stirred for 30 minutes. The obtained suspension contained, on the basis of 235 kg, 100% by weight of 3-methyl-4-nitrosophenol.

The invention is applicable to the production of 3-methyl-4-nitrosophenol which is an intermediate in the production of several organic substances, for example O, O-dimethyl-O- (3-methyl-4-nitrophenyl) thiophosphate.

Claims (1)

OBJECT OF THE INVENTION Process for the preparation of 3-methyl-4-nitrosophenol by nitrosation of 3-methylphenol with an aqueous solution of sodium nitrite in a mineral acid medium, characterized in that the nitrosation is carried out in the presence of a surfactant.