HU198449B - Process for production of asimmetrically substituated carbamides - Google Patents

Abstract

The invention relates to a process for the preparation of N-substituted ureas by reacting carbon oxide, water and nitro compounds, or by reacting carbon oxide, nitro compounds and amines, in the presence of organic and/or inorganic selenium compounds with catalytically active selenium and in the presence of water and/or bases, in which process the catalytically active form of the selenium is prepared from selenium-containing compounds by physical, chemical or photochemical means before or during the carbonylation reaction. The selenium compounds used as catalysts for this process are stable under normal conditions and can be converted into the catalytically active form by a suitable activation process. The use of the selenium compounds which have previously been employed as catalysts of the carbonylation reaction and which cause handling problems can therefore be avoided according to the invention. The N-substituted ureas prepared by the above process are mainly used in the crop protection chemicals industry.

Description

The present invention relates to a process for the preparation of N-aryl-N ', N-dialkylureas of formula I wherein R, H, halogen or halogenated C 1-4 alkyl, R ₂ and R _{3 are the} same or different C 1 -C 6 represents an alkyl group.

Substituted ureas are gaining importance. Some derivatives are prepared for direct use as intermediates for the synthesis of additional substances, others for their fungicidal, insecticidal or herbicidal activity, primarily of agricultural origin.

A number of processes for preparing symmetrically and asymmetrically substituted ureas are known. Some of these are based on the reaction of aliphatic or aromatic isocyanate with the corresponding amine, others based on the reaction of carbamoyl chloride and amine. Indirectly, both reaction edges require the use of phosphene, and this requires the practical realization of urea synthesis, which causes obvious difficulties in the practical realization of urea synthesis. Therefore, many attempts have been made over the past two decades to develop methods that require less reactive materials and less corrosive conditions for the production of substituted ureas.

No. 193,492. U.S. Pat.

No. 1,378,481. United Kingdom Patent No. 5,123,198 discloses the reaction of an aliphatic or cycloaliphatic primary amine with a secondary anionic salt of N, N-disubstituted urea. The reaction is carried out in an inert solvent at 50 to 200 ° C under atmospheric or medium pressure. Yields are generally above 80%.

No. 243,591. United Kingdom Patent No. 4,122,125 discloses that catalytic conversion of amines to ureas is also possible. A disadvantage of this solution is that a significant amount - sometimes all - of the starting amine is not carbonated to the desired product, but to formamide.

No. 3,737,428. U.S. Pat. No. 4,102,125 discloses that in the presence of elemental carbon, substituted urea can be prepared from amines and carbon monoxide under very mild conditions. The authors also observed that at a few percent of the oxygen content of carbon monoxide fed into the reaction mixture, urea formation occurs in the presence of a catalytic amount of selenium.

No. 732,252. US Patent No. 4,600,600 uses a mixture of copper (II) chloride and paadlumate (II) chloride as a catalyst for the oxidative carbonylation of amines. The reaction mixture containing the amine and the catalyst is reacted alternately with carbon monoxide and air. This latter step serves to regenerate the calixiser. In all the above procedures, amines are used as starting materials for the synthesis of substituted urea derivatives. However, in the case of aromatic amines, the directly available raw material is generally the corresponding aromatic nitro compound, and therefore several methods have been developed for the synthesis of N-aryl ureas from aromatic nitro compounds.

Trisubstituted ureas were prepared non-catalytically by the method described in U.S. Patent No. 3,911,006. U.S. Pat. The patent discloses that the desired target compound is formed in good yield in the reaction of the secondary ammonium salts of the aromatic nitro and n-nitroso compounds with Ν, Ν-disubstituted thiolcarbamates. Since the second reactant also acts as a reducing agent, at least three molar equivalents should be used to achieve complete conversion of the nitro compound. Although the amine and sulfur formed from the tolylcarbamate, which reacts as a bar reducing agent, this solution will certainly result in increased material utilization. No. 4,115,445. According to U.S. Pat.

No. 3,335,142. U.S. Pat. The use of a mixture of precious metals and lewis acids as catalysts, the use of relatively high pressures and the use of precious metal catalysts renders the process industry unfavorable and uneconomic,

U.S. Pat. No. 4,052,454 and U.S. Pat. No. 1,484,335. United Kingdom Patent Nos. 4 to 5, 6 and 9, teach substituted carbamates by the catalytic reaction of aromatic nitro, nitroso, azo or azoxy compounds, carbon monoxide, and primary or secondary amides. The catalysts used are sulfur, selenium and their chemical compounds. The authors mention that small amounts of water and base added to the reaction mixture favorably affect the reaction. The disadvantage of this process is that it provides the desired asymmetrically substituted ureas in a relatively low yield of 35% to 75%, which has been found to be due to inadequate catalyst activity.

It is an object of modifying the latter process to develop a method for producing the desired asymmetrically substituted ureas in high yield in a short reaction time.

In our experiments, it has been found that certain selenium compounds which are substantially free of catalytic activity can be converted into highly active catalysts by appropriate pretreatment and in the presence of the desired asymmetrically substituted urea derivatives from the corresponding aromatic nitro compounds, monoxide.

The present invention therefore relates to a process for the preparation of N-aryl-N ', N-dialkylureas of formula I wherein R 1 is hydrogen, halogen or halogenated C 1 -C 4 alkyl and R ₂ and R _{3 are the} same or different 1 - R 6 represents aromatic nitro compounds of the formula II - in the formula ε - the aliphatic amines of the formula - wherein R ₂ and R ₃ are as defined above - by volume of carbon monoxide and tertiary amine base in the reaction mixture from 0.05 to 1.0 by volume) of water, and selenium-containing catalyst, by the reaction at a temperature of 120-200 C, ^D, 10 to 60 bar carbon-21 killer oxide pressure. According to the invention, as a selenium-containing catalyst

a) 1 mole of the selenium compound is at least 1 mole of hydrogen peroxide, an organic hydroperoxide or an organic peracid from 25 to 100 ° C in the pre-treated (IV) organic foszfln selenide of the formula: - wherein R ₄ and R _s is phenyl, X is phenyl or - (CH ₂ ) p (Se) (C ₄ H _s ) j, wherein n is 1 or 2 -, 'or

b) An alkali metal selenocyanate or an alkali metal selenosulfate, pretreated at 10-40 ° C with at least 0.1 mol of non-oxidizing mineral acid or C 1 -C 6 alkanoic acid, is used per mole of selenium compound and the reaction mixture has the general formula (II): the molar ratio of nitro compound to 1: 0 to 1:50 is maintained.

As the tertiary amine base in the reaction, the compound of U.S. Pat. U.S. Pat. No. 1,484,335; Any tertiary amine listed in British patents may be used, including basic heterocyclic compounds containing a nitrogen atom as a ring member. Examples of suitable tertiary amine bases include: trimethylamine, triethylamine, tri (tertiary butyl) amine, pyridine, collidine, quinoline, isoquinoline,,, N-dimethylaniline, N, N, N , N-tetramethylethylenediamine and bicyclic amidines such as 1,8-diazabicyclo [5.4.0] undec-7-ene and 1,5-diazaabicyclo [4,3,0]. non-5-ene.

In order to obtain satisfactory results, the reaction mixture must contain at least 0.05 volumes of water. However, the water content should not exceed 1.0% by volume, otherwise the formation of an aromatic amine corresponding to the starting nitro compound may be promoted.

The solvent may also be used in the reaction in the presence of an aliphatic amine (II) or tertiary amine base (II) used as the reactant. tetrahydrofuran or dioxane may also be added.

The individual reagents may be weighed in the reaction in a stoichiometric ratio, but it is preferable to use an excess of amine (III) and carbon monoxide.

The catalyst peripheral compound can also be activated in a preliminary step, but it is also possible to directly add selenium compound and activator to the reaction mixture, thereby activating the assay compound itself in the initial reaction stage. During the activation process, it is believed that the starting selenium dissolved in the reaction mixture forms an extremely fine dispersion of the catalytically active form, resulting in an increase in the reaction rate.

The reaction time for the complete conversion of the nitro compound of formula II may vary from 10 minutes to 5 hours, depending on the parameters used. After complete conversion, it is advisable to cool the reactor immediately to avoid possible thermal decomposition of the product. i

The invention will be further described in the following examples without limiting the scope of the invention.

Example 1

To a 300 cm ³ autoclave were 3.6 g (30 mmol) of nitrobenzene, 60 cm ^{3 of} tetrahydrofuran, 10 cm ^{3 of} triethylamine, 15.5 cm ³ (3 mmol) of dlethylamine, 1.0 g (3 mmol) triphenylphosphine selenide and 0.61 g of m-chloroperbenzoic acid were weighed. (The triphenylphosphine selenide is prepared as described in Inorg. Chem. 5, 1297/1966.) The reactor is sealed, the air is evacuated with carbon monoxide, and the carbon monoxide pressure is adjusted to 25 bar. After stirring was started, the temperature of the reaction mixture was raised to 160 ° C and the reaction was carried out at this temperature for 30 minutes. Analysis shows complete conversion of nitrobenzene to yield the desired N-phenyl-N ', N' -dlethylurea in 91% yield.

Example 2

All were carried out as in Example 1, but the m-chloroperbenzoic acid activation was quenched. No carbonylation reaction was observed.

Example 3

The procedure described in Example 1 was followed, except that 3.6 g (30 mmol) of nitrobenzene, 9.1 g of N-ethyl-N-butylamine, 0.5 g (1.5 mmol) of triphenylphosphine were used. and 0.4 g (2 mmol) of m-chloroperbenzoic acid. The water content of the reaction mixture was adjusted to 0.4% by volume, the temperature to 130 ° C and the carbon monoxide pressure to 50 bar. After 60 minutes, the desired N-phenyl-N-ethyl-N'-butylcarbamide is obtained in 83% yield.

Example 4

The procedure described in Example 1 was followed, but from 5.4 g (44 mmol) of nitrobenzene, 17.0 g of di-n-butylamine, 0.5 8 0.5 mmol) of triphenylphosphonic selenide and Starting from 21 g (1.6 mmol) of tert-butyl hydroperoxide. The water content of the reaction mixture was adjusted to 0.5 volumes, the temperature to 180 ° C, and the carbon monoxide pressure was adjusted to 30 bar. After 45 minutes, the desired N-phenyl-N ', N-di-n-butylurea was obtained in 72% yield.

Example 5

The procedure described in Example 1 was followed, except for 4.7 g (30 mmol) of 4-chloro-nitrobenzene, 5.5 g of diethylamine, 0.41 g (0.76 mmol) of (Ph ₂ PSe) _2. Start with CH ₂ selenide and 0.4 g (2 mmol) of m-chloroperbenzoic acid. The water content of the reaction mixture was adjusted to 0.1% by volume, the temperature to 160 ° C and the carbon monoxide pressure to 45 bar. After 45 minutes, the desired N- (4-chlorophenyl) -N ', N'-diethylcarbamide is obtained in 87% yield.

Example 6

The procedure described in Example 1 was followed, except that 5.7 g (30 mmol) of 3- (trifluoromethyl) nitrobenzene, 10.0 g of diethylamine, 1.0 g (3 mmol) of triphenylphosphine were used. selenide and 0.75 g (3 mmol) of m-chloroperbenzoic acid. The water content of the reaction mixture was adjusted to 0.1% by volume, the temperature to 160 ° C and the carbon monoxide pressure to 50 bar. After 45 minutes, the desired N- (3-trifluoromethyl-phenyl) -N ', N'-diethylurea is obtained in 69% yield.

198 449

Example 7

300 cm ³ pressure-resistant reactor was 50 cm ³ diocánt (3 mmol) of triphenylphosphine and 1.02 g of 5-selenide cnt 0.15 ³ 70% hydrogen peroxide to .- (4 mmol) were charged and 10 minutes at room temperature activating the catalyst. 5.4 g (44 mmol) of nitro-benzene, 10 g of the reactor is placed in _o-diethyl amine and 10 cm ³ of triethylamine after adding under a carbon monoxide pressure of 40 bar, then thermostated at 150 160 ° C for 1 h. The water content of the reaction mixture is 0.07% by volume. Analysis yields the desired N-phenyl-N ', N'-dimethylurea in 85% yield. '

Example 8 4 g

To a 300 cm ³ autoclave was added 3.6 g (30 mmol) of nitrobenzene, 50 cm ^{3 of} tetrahydrofuran, cm ^{3 of} triethylamine, 15.5 cm ^{3 of} diethylamine, 0.44 g (3 mmol) of rumor selenocyanate and 0.25 cm ³ (4.2 mmol) glacial acetic acid. (Potassium selenocyanate is described in Inorg.

Synth. 2, 186 and 1946.) After removing the air, the carbon monoxide pressure is adjusted to 25 bar. The water content of the reaction mixture is 0.15 vol. The reaction mixture was heated to 160 ° C with vigorous stirring and kept at this temperature for 12 minutes. Analysis gave the desired N-phenyl-N ', N-diethylurea in 80% yield.

Example 9

The procedure of Example 8 was followed, but glacial acetic activation was omitted. The edible product was obtained in a yield of less than 5%.

Example 10

To a 300 cm ³ reactor was added 3.6 g (30 mmol) of nitrobenzene, 60 cm ^{3 of} tetrahydrofuran, 10 cm ^{3 of} triethylamine, 15.5 cm ^{3 of} diethylamine, 0 70 g (3 mmol) of J selenosulfate and 0.25 cnr of 10% aqueous hydrochloric acid (0.7 mmol hydrochloric acid). (Carousel selenium sulfate, F.Foerester et al., Z.

Anorg. Hardly. Chem. 128, 313 (1912). The water content of the reaction mixture is 0.25% (v / v). After removing the air, the carbon monoxide start pressure is set to 25 bar and the reactor is heated to 160 ° C. After 30 minutes, the reaction mixture was cooled and analyzed by thin layer chromatography and gas chromatography. Analysis showed N-phenyl-N'-N'-diethylcarbamide to be formed in 82% yield.

Example 11

All proceed as in Example 4, except that 1,2-bis (diphenylphosphino) ethylene diselenide was used as a catalyst in 0.834 g (1.5 mmol) with 0.42 g of 70% tert-butyl hydroperoxide. (3.3 mmol tert-butyl hydroperoxide) was activated. N-phenyl-N'N'-n-butyl urea is obtained in a yield of 5%.

Claims (1)

Patent Claim A process for the preparation of N-aryl-N ', N'-dialkylcarbamides of formula (I) R 1 is hydrogen, halogen or halogenated C 1 -C 4 alkyl, and R 1 and R _{3 represent the} same or different C 1 -C 6 alkyl aromatic nitro compounds of formula II wherein R 1 is the aliphatic amine of formula III wherein R ₂ and R ₃ are as defined above - carbon monoxide and tertiary amine base by reaction of 0.05 to 1.0% by volume of water with a catalyst containing 10% to 60 bar of carbon monoxide in the presence of a catalyst containing selenium as the catalyst a) 1 mole of the selenium compound is at least 1 mole of hydrogen peroxide, an organic hydroperoxide or an organic peracid 25-100 C pretreated (formula IV) an organic phosphine selenide ° - wherein R ₄ and R _s is phenyl, X is phenyl or - (CH) nP (sexc H ₅₎ j represents a group, wherein n is 1 or 2 -, or b) Alkali metal selenoclanate or alkali metal selenosulfate pretreated with at least 0.1 mol of non-oxidizing mineral acid or C 1-6 alkanoic acid per mole of selenium compound is used, and the selenium-containing catalyst has the following general formula: a molar ratio of 1:10 to 1.50. 1 drawing