SU732252A1 - Method of preparing n,n'-substituted urea - Google Patents

Description

one

The invention relates to an improved process for the preparation of substituted urea of the general formula:

h R / .4

where cd "H, CHj, CjHj, iso-CyRju 1

R CHaCjj H j, C H, Io-C, H, iso-C H j, CH j, or R pipiridine, morpholine, and can (used in preparative and synthetic organic synthesis to obtain bicoco, for example, herbicides.

A method is known for producing substituted urea from amines and CO at high temperatures of 100200 ° C and pressure of 100-1000 atm, using carbonic manganese as catalyst 1.

However, the use of this method is associated with high temperatures and pressures, which prevents its use in industry.

The closest to the invention in its technical essence and the achieved result is the method for producing N, N-substituted urea by oxidative addition of oxide

carbon to amines in the presence of copper (I, II) complexes under mild conditions.

The reaction is carried out mainly at 0-100 C. The process goes faster if pipyridine, morpholine, pyrrolidine, dimethylamine, dibutylamine or mixtures of these amines are taken as amines. When using these amine compounds, the reaction is carried out at room temperature and atmospheric pressure. Other amines require a higher temperature and CO pressure. The reaction is carried out as without solvents.

15 and in inert organic solvents. A small admixture of HjO does not interfere with the reaction. The mixture is brought into contact with CO and O2 12).

The disadvantages of this method -

20 low speed of the process, since the maximum catalyst activity is about 1.5 mol of the target product per 1 mole of catalyst (cat.)

25 per hour, high process temperature and pressure when using primary ctMHHOB, low stability of catgizer at elevated temperatures () and in the presence of oxygen (5 mol.%). The Cat system (11.1) rather poorly activates CO. This is due to the fact that copper (P) does not interact with CO at all, and copper (I), although coordinating CO, but the complex of CCO decomposes at elevated temperatures () (this process is used in purifying gases from CO and CO from other gases ) and in the presence of oxygen, while CSO plays a significant role in the reaction. The purpose of the invention is to simplify the process and increase the reaction rate. This goal is achieved by the described method of obtaining total N, N substituted urea (by oxidative addition of carbon monoxide to amines by heating in the presence of copper complexes and PdCIg palladium salt as a catalyst in the ratio Pd / Cu 1: 100-1: 1. The process is Pd / C ratio 1: 10-1: 3. Example 1. In the reaction mixture, 0.5 mmol PdCI (0.090 g), 1.5 mmol CuCl2, 2H2O (0.155 g), 5 ml n-butylamine, 35 ml of dioxane. The temperature is 40 ° C, the pressure is CO 1 atm. The reaction takes place while the mixture is stirred intensively and held in contact with CO and air. alternately. The CO absorption control is carried out volumetrically. After 14 oxidation-reduction cycles, 0.323 L CO (N) is absorbed. The total reaction time is 2.5 hours, the average speed is 2.9 mol / mol cat. h. After the reaction is stopped, the solvent is filtered off. It is distilled off under vacuum, the solid residue is dissolved in ether and extracted with 50 ml of concentrated LiCl, filtered, dried over MgSO4, the ether is evaporated, 2.3 crystalline light brown color are separated (93.2% on CO, reacted). After recrystallization from an alcohol – ether solution, 2.12 g of colorless crystals were obtained (85.5% on CO). Dibutylurea is identified by t {70-71 c) and electronic analysis. Calculated: 62.79% C; 11.62% N. Received: 62.41% C; 12.27% H. Example 2. In a reaction vessel, 1 mmol (0.177 g), 5 mmol (0.850), 5 ml of piperidine, 28 ml of pyridine are placed. Temperature, pressure CO 1 atm. The reaction is carried out by the method of Example 1. During 17 oxidation-reduction cycles, 0.552 liters of CO is absorbed. The total reaction time is 1 h 42 min. The average rate is 2.4 mol / mol cat. “After appropriate treatment, 4.06 g of a light brown substance (85% on CO) was released. After recrystallization from ether, 3.74 g of white needles (78% on CO) remain. Dipipyridine urea is identified by t (50-51 ° C) and elemental analysis. Calculated: 67.30% C; 10.2% H; 14.3% Nf Received: 67.58% C; 10.46% H; 14.0% N. Example Z. In a reaction vessel, 0.1 mmol of PdCIg (0.018 g), 10 mmol of CICD-3H O (1.700 g), 5.5 ml of benzylamine and 40 ml of pyrcine are placed. The temperature is 40 ° C, the pressure is CO 1 atm. The reaction is carried out with intensive stirring of the mixture, which is brought into contact with CO and air alternately. Control over the absorption of CO is volumetric and. 4 cycles of oxidation-reduction were carried out. The total amount of absorbed carbon monoxide 457 ml, the total time of the experiment 26 minutes The average rate is 5.58 mol / mol of the catchet. The solvent is distilled off under vacuum, copper salts and palladium are extracted from the precipitate with 50 ml of 10% aqueous ammonia solution. The residue is washed on a glass filter with first 200 ml of 10% aqueous ammonia solution, then 200 ml of ether and dried in a vacuum desiccator over HjSO (concentrated). 4.38 g of N, N-dibenzylurea are isolated as a white crystalline substance. CO yield 91%. Identification is carried out by IR spectra and elemental analysis. %) from 1635. Calculated: 75% C; 6.7% H; 11.7% N; Received: 73.5% C; 6.8% H; 11.9% N. Example 4. In a reaction vessel, 1 mmol of PdCI (0.177 g), 1 mmol of CuCl-2H, O (0.170 g), 5 ml of benzylamine and 45 ml of pyridine are placed. Temperature, pressure WITH 1 atm. The reaction proceeds with vigorous stirring of the mixture, which is brought into contact with CO and air alternately. The monitoring of the absorption of CO is volumetric. A total of 5 cycles of oxidation of reduction was carried out. The total amount of CO absorbed was 95 ml, the total run time was 9 min. The average reaction rate is 16.2 mol / mol cat. h. The introduction of the product N, N-dibenzylurea was carried out according to example 3. Received 0,886 g of dibenzylurea, yield. 87% for CO 1580; 1635 cm. Example 5. In a reaction vessel, 0.5 mmol PdCI (0.090 g), 5 mmol CuCIj -2 H2O (0.850 r) j 6 ml of dimethylamine (33% aqueous solution) and 40 ml of pyridine are placed. The temperature of the experiment, the pressure of CO 1 ATM. The reaction proceeds by intensive agitating of the mixture, which is brought into contact with CO and air alternately. Control over the absorption of CO volumetric. A single oxidation-reduction cycle was carried out. The amount of absorbed carbon monoxide was 51 ml, the test time was 39 minutes, the average rate was 0.64 mol mol cat. h. The solvent from the mixture is distilled off under vacuum, the residue is poured over 50 MP of an aqueous solution of ammonia

extracted twice with 20 ml of ether. After evaporation of the ether and drying in vacuo, a viscous yellowish liquid remains. IR: vco 1660. Isolated 0.040 g of tetramethylurea. Yield 15% for CO.

The table shows the comparative data for obtaining N, s substituted urea by known and proposed methods.

Claims (2)

Claim 1. The method of obtaining N, N'-substituted urea of the formula: R, NCH \ ^K 2. ^R g (I) where CH ₃ .C ₂ H ₅ , iso% H _{al (} or I _d and pipyridine, morpholine ,. by oxidative addition of carbon monoxide to amines when heated in the presence of copper complexes as a catalyst, it is possible that, in order to __ simplify the process and increase the reaction rate, the process is carried out in the presence of the palladium salt PdCI ₂ in the ratio of Pd / Cu 1: 100 - 1:: 1. 2. The method according to claim 1, characterized by the fact that the process is conducted in a ratio of Pd / Cu of 1:10 - 1: 3.