SU802264A1 - Method of preparing n-alkylaromatic amines - Google Patents

Description

(54) METHOD OF OBTAINING N-ALKYLAROMATIC AMINES

The invention relates to an improved process for the preparation of N-alylaromatic amines by catalytic reductive alkylation of nitrobenzene and its reduction products, namely azobenzene, azoxybenzene and aniline. The resulting N-alkyl aromatic amines are used as drugs, antioxidants, and semi-organic compounds l). A known method for producing N-alkylated aromatic amines by reductive alkylation of nitrobenzene and its reduction products with carbonyl compounds in the presence of a catalyst of composition: 0.23–8.41 wt.% Tetrahalide bis (dimethyl sulfide) platinum 0.1–3.94 wt.% Haloanilic acid, the rest of the carrier (A1-0 "or activated carbon). The process is carried out at 20-130 ° C and a pressure of 1-16 atm. The yield of the target products is 57-98.5%. The disadvantages of the method are low catalyst activity (0.2211, 95 mol g-at m-min) and the use of platinum, the most expensive metal of the eighth group 2. Also known is the method of producing M-alkyl aromatic amines that is closest to the proposed method by reductive alkylation of nitrobenzene to its reduction products in the presence of tetrahaloid parasols deposited on polytrimethylolmelamine or aminated chloromethylation copolymer of styrene and divinyl benzene. The process is carried out at a temperature of 20-80 ° C and a pressure of 1-6 atm. The yield of the target products is 18-99%. The disadvantage of the method is the low activity of the catalysts (0.2320, 31 mol N / g-at. M "min Gz. The aim of the invention is to increase the efficiency of the process. The goal is achieved by carrying out a process of reductive alkylation of nitrobenzene and its reduction products (azobenzene, azoxybenzene and the analyte) carbonyl compounds in the presence of catalysts, which are complex compounds of the platinum group metals with oxyquinones of the general formula MC, where M is Pt, Pd, in the case where the catalyst is used on the carrier, M - Pt, Pd, Rh, (1-1,2-dioxyanthraquinone (alizarin) or sodium 1,2-dioxyanthraquinone-sulfonate (alizarin edge c); deposited on the surface of an inert substrate (alumina, either in the absence of a carrier. In the first case, catalysts are obtained by reacting the complexes with active carrier groups. Special studies (IR, electron, photoelectron spectroscopy) have been shown to form b between the active carrier group and the molecule Plec sa. In the presence of data, the catalytic process of the reductive N-alkylation of nitrobenzene and its reduction products (azobenzene, azoxybenzene and aniline) is usually carried out by carbonyl compounds in a temperature range of ± 0-1 ° C, atmospheric pressure of hydrogen and in an inert solvent (water, alcohols, dimethylformamide). Catalysts before use must be activated by chemical reductants (hydrogen, sodium borohydride). The yield of the target products is 98-99% with a conversion rate of the nitro compound of 99-100%. Catalyst activity 15-30 mol N, / g-at M-min, Pr-meper 1. Preparation of Pd (n) Pt (II) and Rh (ffi) complexes with alizarin red C. A 0.4527 g (1 , 38-10 mol) is dissolved in 30 ml and mixed with 170 ml of a solution of 0.9415 g (2.7610 mol) of alizarin red C treated with an equimolar amount of KOH. The resulting solution is heated for 1 hour in a boiling bath, after which it is kept for 12 hours. 100 ml of ethanol are planted out of the complex. The precipitate is filtered off and dried in a desiccator over CaC Ij. The output of the complex is 0.99 g (90% of theory). Similarly, Pt (11) and Rh (It) complexes with alizarin red C are obtained. Synthesis of Pd (and), Pt (li), Rh (in) complexes with alizarin is also carried out according to the described procedure: Example 2.4 g 2 D Hell. O - carefully evacuate per hour, 100 ° C. To an evacuated alumina in an inert atmosphere, add a solution of the Bd (I) –Alizarin Red C complex (1.84–10 mol) and mix on a magnetically stirred mixer until the solution is completely clear. The resulting catalyst is filtered and dried in a desiccator. The composition of the catalyst weight Pd-alizarin red from 12.66, ossshnnoe. Heterogeneous catalysts containing different Pt (li) and Rh (w) weight assignments are obtained in the same way. When used as aminium silica gel as a carrier, the method for producing catalysts is similar to that described. Example 3. In a temperature-controlled glass reactor, 0.2 g of Pd catalyst (alizarin) is placed in A. 2.0 ° (from example 1) and 10 o ethanol. Then 10 mg of NaBH4 is introduced. and stir the contents of the reactor at 40 ° C under a hydrogen atmosphere for 10 minutes. Thereafter, 0.1 ml (1 mmol of nitrobenzene and 0.2 ml (2 mmol) octanal) are introduced in a stream of hydrogen. The absorption of the aqueous phase is complete after 30 minutes. The catalyst is filtered off; the liquid phase is separated by distillation. 95% M-octylaniline, 2% aniline and 3% of the corresponding azmethine are obtained by GLC. In N-alkylation in water, the catalyst is separated on a separatory funnel. To increase the yield of the target products, the aqueous layer of catalyzate is extracted with ether. t 1 ml solution of platinum complex with a Lizarinsm red With a concentration of 8-10 mol / l. The resulting solution of the pomeg is put into a thermostated glass reactor and activated with hydrogen for 3 minutes. After this, 2 mmol (0.2 ml) of nitrobenzene and 0.54 ml of isobutane. The reaction is carried out at .35 ° C and atmospheric hydrogen pressure. After 35 min., The hydrogen absorption is completed, the mixture is placed in a separatory funnel. The upper layer consists of reaction products, the catcher is in the lower aqueous layer. In order to further extract the reaction products, the aqueous solution is extracted with ether. 98% of N-isobutylaniline and 2% of the corresponding azomethine are obtained. Catalyst activity 33.08 mol. Pt min Example5. In 9 ml of ethanol, 1 ml of a solution of a complex of palladium with alizarin red is placed. With a concentration of 8-U ol / l. Next, activation is carried out and in a stream of hydrogen, 2 mmol (0.2 ml) of aniline and 6 mmol (0.54 ml) of propanal are introduced. The reaction is carried out at 40c and atmospheric pressure of hydrogen. Hydrogen uptake is complete after 27 minutes. Ethanol was distilled off from the reaction mixture and water (10 mp) was added. Further, the separation of the reaction products and the catalyst is carried out analogously to example 4. As a result, 97% of N-propylaniline and 3% of the corresponding Schiff base are obtained. The catalyst activity is 27.86 mol H / r-ai. Pd min The results of the experiments are summarized in table. 1 and 2.

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EH 9802 Thus, the method is according to. The invention allows to significantly intensify the process by increasing the activity of the catalyst. In addition to Toroj, the use of water, the most accessible solvent, is another advantage of the invention. formula of the invention. 1, A method for producing alkyl aromatic amines by reductive alkylation of nitrobenzene, azobenzene, azoxybenzene or aniline with carbonyl compounds in the presence of an inert solvent in a hydrogen atmosphere in the presence of a catalyst, containing platinum group metal compounds, in order to increase the efficiency of the process, as a catcher, platinum-group metal complexes are used with oxychnons of the general formula H (1,, where M-Pt, Pd, in the case when the catalyst is used on a carrier, M-Pt, Pd, Rhj Q-alizarin, alizarin red C;, 2, A method according to claim 1, characterized in that the catalyst is used on a carrier such as polymethylolmelamine, amyrcized dilikagel and alumina oxide, the catalyst ingredients being taken in the following ratio, weight .%: platinum-group metal complex 0.78-12.66, carrier 87.34-99.22, 3. Population method 1, distinguished by the fact that water is used as an inert solvent. into account when expert 1.Berkman B. .E. Industrial synthesis of aromatic nitro compounds and amines. M., Khimi, 1964. 2. Author's certificate of the USSR for application no. 2596025 / 23-04, cl. C 07 C 87/62, 03.29.78. 3 USSR Author's Certificate in Application No. 2625842 / 23-04, cl. C 07 C 87/62, 08.06.78 (prototype,

Claims (3)

Claim 1. A method for producing N-alkylaromatic amines by reductive alkylation of nitrobenzene, azobenzene, azooxybenzene or aniline with carbonyl compounds in the presence of an inert solvent in a hydrogen atmosphere in the presence of a catalyst containing platinum group metal compounds, characterized in that, in order to increase the efficiency of the process, as a catalyst, metal complexes of the platinum group with oxyquinones of the general formula Mi ^, where Μ-Pt, Pd, in the case when the catalyst is used on a support, Μ- Pt, Pd, Rh; Q-Alizarin, 'Alizarin Red C; n = 2-3. 2, The method of pop. 1, characterized in that the catalyst is used on a carrier such as polymethylolmelamine, amylated rilicagel and alumina, the catalyst ingredients being taken in the following ratio, wt.%: Platinum group metal complex 0.78- 12.66, carrier 87.34-99.22. 3. The method according to claim 1, with the fact that water is used as an inert solvent.