DEF0013796MA - - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

Registration date: January 29, 1954. Advertised on March 15, 1956

GERMAN PATENT OFFICE

It is known to be primary, secondary and tertiary aliphatic, cycloaliphatic, and araliphatic aromatic amines with oxidizing agents, e.g. B. peroxy compounds such as hydrogen peroxide and Per-5 oxy acids, to be oxidized, with the most varied of oxidation products, especially nitro and nitroso compounds, oximes, hydroxylamine derivatives, azo and azoxy compounds and amine oxides, have been received. Sometimes such ίο oxidation products arise without. substantial quantities of by-products, but sometimes a variety of reaction products are obtained, e.g. in the reaction of secondary aromatic amines with hydrogen peroxide or sulfomonoperic acid. Methylaniline provides z. B. in such a treatment phenylhydroxylamine, nitrosobenzene, Nitrobenzene, azobenzene, azoxybenzene, formaldehyde, methylenediphenylhydroxylamine, diphenyloxyformamidine and formylphenyl hydroxylamine. From secondary aliphatic amines and hydrogen peroxide on the other hand, corresponding hydroxylamine derivatives have already been produced.

It has now been found, surprisingly, that by the action of at least three times molar amount of hydrogen peroxide or peroxyacids to secondary aliphatic, cyclo-

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aliphatic or araliphatic ^ amines' in smooth Reaction on the one hand the corresponding nitroso compounds or oximes and on the other hand the corresponding Aldehydes or ketones received. The implementation proceeds according to the following scheme:

R ₈ -C

NH

3 O active

> R ₁ NO + R ₃ -C = O. + H ₂ O

In the formulas, R _{1 is} an alkyl, cycloalkyl or aralkyl radical, R _{2 is} an alkyl, cycloalkyl, aralkyl radical or hydrogen, R _{3 is} an alkyl, cycloalkyl, aralkyl radical or hydrogen, and R ₁ and R ₂ or R ₂ and R ₃ can also together be members of a cycloaliphatic _{ring or R 1} and R ₂ together with the N atom can be members of a heterocyclic ring.

This new implementation is technically important because in a number of processes for the preparation of technically important primary amines, the secondary amines are obtained as by-products that were previously difficult to utilize, e.g. B. in the hydrogenation of nitriles, of ketones in the presence of ammonia and in the hydrogenation and optionally reducing ¹ aromatic amines or nitro compounds. For example, when aniline is hydrogenated, dicyclohexylamine is obtained as an undesirable by-product. Such by-products can advantageously be converted into technically valuable substances by the present process.

Suitable secondary amines are e.g. B. dimethylamine, diethylamine, dipropylamine, diisopropylamine, Dibutylamine, Diisobutylamine, Diamylamine, Diisoamylami ^ DihexylaminundDiisohexylammjN-Methylcyclohexylamin, N-ethylcyclohexylamine, N-propylcyclohexylamine, N-isopropylcyclohexylamine, N-butylcyclohexylamine N-isopropylcyclohexylamine and dicyclohexylamine, dibenzylamine, pyrrolidine and piperidine. '

In addition to the free amines, their salts, e.g. B. carbonates or acetates are used will.

Suitable peroxy compounds are e.g. B. hydrogen peroxide and peroxy acids such as peroxymonosulfuric acid (Caro's acid), performic acid, peracetic acid, perpropionic acid, perbutyric acid, adipic diperic acid, Benzoperacid and Phthalmonoperacid.

The peroxy acids are most conveniently in the presence of an inert solvent, e.g. B. gasoline, Methylene chloride, chloroform, carbon tetrachloride, ether, benzene or toluene, with the secondary amine implemented; the hydrogen peroxide is best used in as concentrated a form as possible, e.g. as a 30 to 35% aqueous solution.

The hydrogen peroxide is preferably in the presence of catalysts, e.g. B. Connections of molybdenum or tungsten. The catalysts are z. B. in concentrations of o, oibis5 ° / (, added.

The temperature suitable for the reaction depends on the amine used and, in particular, on the type of oxidizing agent. When using peroxy acids z. B. it is between about - 20 and about - + - 60 °, in particular between 10 and 30 ⁰ , when using hydrogen peroxide, however, temperatures of about 40 to 100 ° are required.

Since the nitroso compounds, their nitroso group on a primary or secondary carbon atom sits, rearrange easily and quantitatively into the isomeric oximes at higher temperatures, it depends from the reaction temperature, whether one uses nitroso compounds or oximes as reaction products receives. Therefore, when using peroxyacids as oxidizing agents, nitroso compounds are generally used, when using hydrogen peroxide, however, oximes are obtained.

The reaction products are separated from unreacted starting material by either fractionally distilling, optionally in vacuo or by extraction of the aqueous solutions at various p _H values from such. B. the aldehydes or ketones and nitroso compounds, at p _H 1 to 2, the oximes at p _H 3 to 6 and the amines at -p _H 12 to 14.

example 1

To a solution of 60 g ⁽¹ Z ₃ moles) of dicyclohexylamine in 800 cc of ether is allowed under stirring at 20 ° internal temperature, 98 g of 78 ° / ₀ peracetic acid (1 mole) is added dropwise. After standing at room temperature for 24 hours, the solution no longer contains active oxygen. It is first extracted with 2N sulfuric acid to remove unreacted starting material, then with soda solution to separate off the acetic acid formed and with bisulfite solution to precipitate the cyclohexanone formed. After evaporation of the ether solution in a weak vacuum, 34 g of a crystallized residue remain, from which 30 g of nitrosocyclohexane are obtained by recrystallization from light gasoline. Melting point 118 to 119 ⁰ . 27 g of cyclohexanone can be liberated from the cyclohexanone bisulfite compound with soda solution. The sulfuric acid extract still contains 4 g of unreacted dicyclohexylamine. Yield of nitrosocyclohexane: 86% of theory; Yield of cyclohexanone: 89% of theory.

Example 2

To 30 g ⁽¹ Z ₆ moles) of dicyclohexylamine and 0.6 g of tungstic acid is allowed at 50 68 ⁰ g of 30% water

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stoffperoxyd ^(x / ₂ moles) is added dropwise such that the temperature rises to ioo ^0th After further heating for one hour at ⁰ ioo the solution allowed to cool to room temperature, is by the addition of 2-η sulfuric acid p _H 3-4 and shakes it with ether several times. After drying the ethereal solution with sodium sulfate, evaporating the ether and distilling the residue in vacuo, 15 g of cyclohexanone and 10 g of cyclohexanone oxime are obtained.

Example 3

67 g are added to a solution of 25 g ( ¹ Z ₄ mol) of diisopropylamine in 200 ecm of ether at 5 to 15 °

! ■ 5 85 ° / o ^e% peracetic acid _^(3/4 moles) is added dropwise and the reaction mixture keeps a further 24 hours at room temperature until the per acid is consumed. After neutralizing with 3o ° / ₀ sodium potash solution separates it from the ether solution, the reaction mixture is extracted with ether twice, and the extracts dried with anhydrous potassium carbonate. The ether is removed in vacuo and the residue, after dilution with mineral spirits to -60 cooled to -70 ^0th The precipitated crystals of 2-nitrosopropane are quickly suctioned off on a cooled suction filter.

By freezing out and sucking off a total of 6 g of 2-nitrosopropane from the melt

■ point 59 to 60 ° after recrystallization

Petrol or ether. The acetone formed at the same time can be both in the aqueous and in qualitatively detect the ether layer.

Example 4

To a solution of 19.7 g (V ₁₀ moles) of dibenzylamine in 200 cc of benzene is allowed under stirring at 20 ° internal temperature, 29 g 78 ° / _o peracetic acid _^(3/10 moles) is added dropwise and the reaction mixture so long as at room temperature, until the peracetic acid is used up. The reaction solution is shaken out first with water and then with bicarbonate solution until the reaction is neutral, and the benzaldehyde formed is precipitated by shaking with bisulfite solution. After evaporation of the benzene solution under reduced pressure, 3.6 g of co-nitrosotoluene are obtained, after recrystallization from chloroform with a melting point of 129 to 130 ^° . 8.2 g of benzaldehyde are obtained in the usual way from the bisulfite solution.

Claims (2)

PATENT CLAIMS: 1. Process for the preparation of aliphatic, cycloaliphatic or araliphatic nitroso compounds or oximes and oxo compounds, characterized in that secondary aliphatic, cycloaliphatic, araliphatic or N-containing heterocyclic amines at least three times the molar amount of a peroxy acid or of Allow hydrogen peroxide to act. 2. The method according to claim 1, characterized in that that the reaction with hydrogen peroxide is preferably carried out in the presence of compounds of molybdenum and tungsten. Referred publications: H ο u b e η -We y 1, Methods of Organic Chemistry, Vol. 2, 3rd edition, 1925, pp. 175, 176 and 179; E. H. Rodd, Chemistry of Carbon Compounds, 1951, Part Ia, pp. 370 and 371; Reports of the German Chemical Society, Vol. 36, 1903, pp. 685 to 710; German Patent No. 664425; Swiss Patent No. 288 168; Journal of the American Chemical Society, Vol. 51, 1929, p. 680. © 509 697/504 3.56