SU891640A1 - Method of producing o-nitrosoarylamines - Google Patents

Description

The invention relates to the improvement of methods for the preparation of o-nitroesarylamines, which are used in organic synthesis. A method for the preparation of o-nitrosoaryl- is known; amines in the interaction of arylamine and nitrosating agents in methanol in the presence of aromatic sulfonic acids 1. The disadvantages of this method are the high consumption of expensive sulfonic acids, the use of a highly toxic solvent and the long duration of the process. There is also known a method of producing o-nitrosoarylamines by treating arylamines with a mixture of sodium sodium sulfate and hydrogen chloride in anhydrous methanol 2. The disadvantages of this method are the use of large quantities of hydrogen chloride, the use of an anhydrous and toxic solvent. The purpose of the invention is to simplify the process. This goal is achieved by using monoalkyl esters of rythylene glycol with the number of carbon atoms in the alkyl chain from 1 to 5, or their mixtures with fractional supply of hydrogen chloride during the course of the reaction as a solvent. The reaction is carried out preferably at 15-25 C. The molar ratio of nitrite and hydrogen chloride to arylamine is taken, respectively, 1: 1.1 and 2.5: 4. Hydrogen chloride is usually used in the form of a 25-48 wt.% (6.8-13 mol / L) solution. The concentration of hydrogen chloride in the reaction mass usually does not exceed 12 May. % A fractional supply of a solution of hydrogen chloride in the solvent is carried out in portions that supply an amount of HC1 equimolecular to arylamine to the reaction mixture for 60–120 minutes, and then the remaining amount of hydrogen chloride in the solvent is introduced to a molar ratio of 2.5: 4. The reaction is carried out with vigorous stirring, the reaction time is 4–4.5 hours. The yield of o-nitrosoarylamines is 90–96% of theoretical. Example 1. In an enameled autoclave equipped with an intensive stirrer, a jacket, a thermometer and connected to a reflux condenser, it is dissolved with stirring.

169 g (1 mol) of diphenylamine in 600 ml of ethyl cellosolve. Then, 71 g (1.03 mol) of powdered sodium nitrite are introduced and, with the stirrer in operation, in three equal portions with an interval of 30 min, 84 ml of a solution of hydrogen chloride in ethyl cellosolve containing 12 mol / l (44 May.%) HC1. The temperature of the reaction is maintained at this 2 (HS. After 90 minutes after the start of the introduction of hydrogen chloride, another 249 ml of HC1 solution is added in the same concentration, maintaining the temperature. The concentration of hydrogen chloride in the reaction mass is about 2.6 mol / L or 9.6 wt.%. The total amount of hydrogen chloride added is 4 mol per 1 mol of diphenylamine. The reaction mass is stirred for another 2.5 h, and then neutralized with cooling 550 ml of saturated soda solution for 1 h. The precipitate is filtered, washed with water and sushi t at 40 ° C under vacuum. The yield of 4-nitrosodiphenylamine 190 g, or 96% of the theoretical.

Example 2. Example 1 84 ml of ztilzellosolva containing 12 mol / l HC1 (44% by weight) are introduced gradually over 45 minutes, then after 16 min another 166 ml of hydrogen chloride solution in the ztilzlozolvo same concentration is added. The concentration of HC1 in the reaction mass is 1.9 mol / l or 7 wt.%, The total amount of HC1 introduced is 3 mol per 1 mol of diphenylamine. After another 3 h, the reaction is completed and the reaction mixture is treated as in Example 1. The yield of 4-nitrosodiphenylamine is 188 g (95% of the theoretical).

Example Z. In an apparatus analogous to Example 1, to a solution of 219 g (1 mol) of N-phenyl-2-naphthylamine in 800 ml of methyl cellosolve, 71 g (1.03 mol) of sodium nitrite was added. Under stirring, maintaining the temperature at 25 ° C, 84 ml of a solution of hydrogen chloride in methyl cellosolve containing 12 mol / l (44% by weight) of HCI are introduced in two equal portions with an interval of 30 minutes. After 60 minutes from the start of the reaction, another 84 ml of the same solution was introduced at 25 ° C, while the concentration of hydrogen chloride in the reaction mass was 0.18 mol / l or 3 wt.% .. The total amount of HC1 used is 2 mol per 1 mol N-phenyl-2-naphthylamine. The mixture is stirred for another 2 h at the same temperature, and then treated analogously to example 1 with an excess of saturated soda solution. The output of N- (4-nitrosophenyl) -2-naphthylamine 232 g, or 93% of theoretical.

Example 4. Analogously to Example 1, 71 g of solid nitrite is added to a solution of 121 g of N-ethylaniline in 400 ml of methyl cellosolve

Sodium and three portions with an interval of 40 min. introduced 135 ml of a solution of hydrogen chloride in methyl cellosolve containing 7.3 mol / l (26.6 wt.%) HCl, maintaining the temperature at 20 ° C. After 120 minutes from the start of the reaction, another 170 ml of a solution of hydrogen chloride in methyl cellosolve containing 12 mol / l (44 wt.%) HC1 was introduced, maintaining the same temperature. Concentration of hydrogen chloride in

the reaction mixture at 2.3 mol / l; or 8.5 wt.%. The total amount of HC1 is 3 mol per 1 mol of N-ethylaniline. The contents of the autoclave are stirred for another 2.5 hours at 20, and then treated with a saturated solution of soda with

a slight excess. The product is extracted with three to four portions of 400 ml ether, which are combined together, after which the ether is distilled off. Then at 40-50 ° under vacuum (residual pressure of 10 mm Hg) volatile substances, mainly methyl cellosolve, are distilled off. The output of N-ethyl-4-nitrosoaniline 145,5 g (96% of theoretical).

Example 5. Analogously to example 1, from 183 g of 4-methyldifensh1amine receive 204 g

4-methyl-4-nitrosodiphenylamine. Output - 96% of theoretical.

Example 6. Analogously to Example 1, out of 195 g of 4-methoxyphenylamine, 217 g (95% of the theoretical) of 4-methoxy-4-ytrosodiphenylamine are obtained.

Example 7: Analogously to Example 1, in the nitrosation of diphenylamine in the medium of n-propyl cellosolve, the yield of the 4-nitrosodiphenamine is 96% of the theoretical value.

Example 8, analogously to example 1, the yield of 4-nitrosodiphenylamine when the reaction is carried out in the medium of n-butyl cellosolve is

95% of theoretical.

Example 9. Analogously to Example 1, the yield of 4-nchrosodiphenylamine, when conducting the reaction in n-amyl cellosolve, is 95% of the theoretical.

Claims (2)

Invention Formula The method for the preparation of o-nitrosoarylamines by the interaction of secondary arylamines with sodium nitrite in the presence of hydrogen chloride in an organic solvent medium, in that, in order to simplify the process, ethylene glycol monoalkyl ethers with an amount of carbon atoms in the alkyl chain from 1 to 5 are used as a solvent. , or a mixture of them, and the process is5891640 4 They are given at a fractional amount of chlorine and vodor1. USSR author's certificate N 48339S, along the reaction.kl. C 07 C 87/49, 1975. Information sources, 2. Patent Fraction fP 783088, published. 1935, taken into consideration pr expertise (prototype).