DE2941141A1 - Catalyst for aromatic e.g. phenyl mono:isocyanate prodn. - contg. palladium chloride, a Gp=VB metal oxide, a Gp=VIB metal oxide, and a pyridine or alkyl-substd. pyridine (AT 15.4.81) - Google Patents

Abstract

New catalyst (I) for the synthesis of aromatic monoisocyanates contains (A) 1.64-16.6 wt.% palladium chloride, (B) 0.16-47.6 wt.% of a group Vb metal oxide, (C) 1.5-81.8 wt.% of a group VIb metal oxide, and (D) pyridine or an alkyl-substd. pyridine to 100 wt.% (I) is used, in the prodn. of aromatic monoisocyanates such as phenyl isocyanates, useful as intermediates for non-toxic agricultural chemicals, and mono- and dichloro-substd. monophenyl isocyanates useful as intermediates for pesticides and plant growth regulators. Using the new catalyst, which has a relatively low palladium cpd., conversion of nitro cpds. into isocyanates is 95-100% and yields of isocyanates are 66-97%. Throughput is 10-39 g end product per g. PdCl2 per hr.

Description

description

The present invention relates to processes for the synthesis of aromatics Monoisozysnate, as well as the necessary catalyst.

The invention is used, for example, in the production of phenyl isocyanates applied, an industrial resource for the production of non-toxic agricultural products Preparations for the synthesis of mono- and dichloro-substituted monophenyl isozysnates. which are used in the manufacture of pesticides and growth regulators for plants be used.

A heterogeneous catalyst for the synthesis of aromatic is named Monoisocyanates, including m-bromine, o- and p-chlorophenyl isocyanate, which contain 5-15% by weight Contains palladium on pumice, promoted with salts of silver, manganese, Cobalt, Gold, nickel, iridium in an amount of 5-20% by weight.

The known catalyst is at 100-240 ° C, a pressure of 1-150 at used for 1.2-3 hours and one obtains halogen-substituted phenyl isocyanates with a yield of 5-15%. The performance of the catalyst is 0.5-1.5 g of the end product (PdCl2) per hour, (GB-PS 1 205 521).

In addition, a homogeneous catalyst is known, that of palladium dichloride (0.5-5 wt. S) in a mixture with acetonitrile. In the presence of this catalyst is obtained at 2000C, a pressure of 50-700 atm and a reaction time of 4-8 hours p-chlorine and 2,4,6-trichlorophenyl isocyanate with a yield of 24-35% in one conversion of the nitro compound from 44-87%. The performance of this catalyst is 2-5 g final product / g PdCl2 per hour (U.S. Patent 3,576,836). The shortcomings of this catalyst are minor Activity, long reaction time - up to 8 hours, as well as low performance.

A homo-heterogeneous catalyst is also known, which is used in the Synthesis of aromatic monoisocyanates, and in particular of phenyl isocyanate used which contains 30-60% by weight palladium chloride and 40-70% by weight vanadium pentoxide. In the absence of this catalyst one obtains at a pressure of 5-9U at, one temperature of 100-200 O after 4-5 hours phenyl isocyanate with a yield 82-92% and at the conversion of nitrobenzene 90-100%. The selectivity is 82-92%.

The disadvantages of this catalyst are the necessity of the previous one Processing with carbon oxide for activation, long reaction time - up to 5 hours and low output - 3 g isocyanate / g (PdCl2) per hour.

The present invention aims to avoid the disadvantages mentioned.

The present invention was based on the object, such to develop a catalyst for the synthesis of aromatic monoisocyanates, which Components and contained in such an amount as to allow the activity of the catalyst and the synthesis performance increases.

The object is achieved in that the catalyst for synthesis aromatic monoisocyanates, the palladium dichloride and a metal oxide of the V group B of the Periodic Table of the Elements, according to the invention additionally contains a metal oxide the VI. Group B of the periodic table and pyridine is added, with the content of the components mentioned (in wt.) is the following: I palladium dichloride 1.64 - 16.6 II metal oxide of group B 0.16 - 47.6 III metal oxide of VI. Group B 1.5 - 81.88 IV pyridine or alkyl-substituted pyridine all the rest - up to the topping up to 100.

Appropriate ranges are for I 1.8-6.8 and 8-15; for II 2.2-8.5 and 14-15; 27-30 and for III 1.5-2.5; 8-10; 14-19 and 40-50.

The present invention enabled the synthesis to be carried out aromatic monoisocyanates with high conversion of the starting compound (up to 100 %), higher yield of end product (up to 97) and greater output - up to 40 g end product / g (PlCl2) per hour.

According to the invention, a catalyst is proposed for the synthesis of aromatic Monoisocyanates, for example of tolyl isocyanate, phenyl isocyanate, 4-methylphenyl isocyanate, 4-chlorophenyl isocyanate, 3-chlorophenyl isocyanate, 2-chlorophenyl isocyanate and 3, 4-dichlorophenyl isocyanate.

The catalyst according to the invention consists of 1.64-16.6 wt .-, °; Palladium dichloride, 0.16-47.6% by weight metal oxide of Group B V of the Periodic Table, for example Vanadium pentoxide, niobium pentoxide, tantalum pentoxide, 1.5-81.8% by weight metal oxide of VI. Group B of the periodic table, for example molybdenum dioxide, tungsten dioxide, and pyridine or its alkyl-substituted in an amount of 1.64-89.8% by weight.

Experiments have shown that if the composition deviates beyond the limits mentioned above, the yield of the end product and the performance abruptly decrease in the process. For example, if the maximum content of palladium dichloride (of 16.6% by weight) the performance of the process, and with a content of palladium dichloride under the mentioned l, 4 % By weight, a reduction in the conversion and the yield of the end product is observed. In the case where the amount of pyridine in the catalyst according to the invention is higher than 89.8% by weight, the performance of the synthesis and with a content of pyridine falls below The conversion falls 1.64% by weight and the yield and performance of the decreases Catalyst. With the help of experiments it was also found that with quantities of the metal oxide of V group B of the periodic table below 0.16 wt.% the selectivity decreases and with amounts of this Eomponente in the catalyst over 47.6 wt the selectivity also decreases. With a content of the metal oxide VI. Group B of the periodic table below 1.5 wt. A reduction is observed the performance and if the mentioned 81.8 wt .-% is exceeded, there is a reduction the selectivity.

As is known, the palladium dichloride is the main component in the catalyst for the synthesis of isocyanates. Nevertheless, it is without additives in this process not active.

It was found that in the presence of pyridine and the metal oxides of the V. Group B and VI. Group B the activity (performance) and selectivity of the catalyst therefore increases because the palladium dichloride is the most catalytically active with these additives Form forms.

The introduction of one of the metal oxides of Group VI B of the periodic table and the pyridine in the composition of the catalyst allows synthesis carry out a pressure of> 0-150 at, the content of expensive palladium dichloride reduce and increase the performance of the catalyst by 4-6 times. Of the Catalyst proposed in the present invention is prepared by the previously dehydrated components in a solvent (mono- or dichlorobenzene) mixed immediately before loading the reactor. Del catalyst according to the invention is at a CO pressure of 50-150 at a temperature of 90-220 ° C and a duration the synthesis used for 2 hours.

When using the catalyst of the invention for synthesis aromatic monoisocyanates, the conversion of nitro compounds will be 95-100%, a yield of isocyanates - 66 - 97%, an output 10-39 g end product g (PdCl2) per hour and a selectivity of 66-97 was observed.

Example 1.

An autoclave with a capacity of 0.15 l is filled with 10 ml of chlorobenzene and a catalyst charged with the following composition: 1.64% PdCl2 (0.01 g), 81.8 »MoO3 0.5 g) 0.16% V205 (0.001 g), 16.4% (0.1 g) pyridine is added 1 g nitrobenzene. The mixture is made with carbon monoxide blow through that The pressure of the carbon oxide is increased to 100 atm and the mixture becomes two at 210 ° C Heated for hours. After cooling, the reaction products are separated from the residue and analyzed with the aid of the gas-liquid chromatography method. The conversion of nitrobenzene is equal to 95%, the yield of phenyl isocyanate is 82%, the performance of the catalyst 39, g phenyl isocyanate / g PdC12 per hour.

Example 2.

The carbonylation of 6 g of nitrobenzene takes place under the conditions as in Example 1 at 200 ° C and a pressure of carbon oxide 100 at in the presence of the catalyst with the following composition: 16.6% PdCl2 (0.1 g), 8.4% MoO3 (0.05g), 8.4% Ta2O5 (0.05 g) 66.6% pyridine (0.4 g). The conversion of nitrobenzene is 100, the yield of phenyl isocyanate - 90%, the performance of the catalyst - 27 g PhenylisozyanatSg PdCl2 per hour.

Example 3.

The carbonylation of nitrobenzene takes place under conditions such as in Example 1 at 190 ° C and a pressure of carbon oxide 100 at in the presence of a Catalyst with the following composition: 4.6% PdCl2 (0.02 g), 46.5% MoO3 (0.2 g), 2.4% Nb2O5 (0.01 g), 46.5% pyridine (0.20 g).

The conversion of nitrobenzene is 90%, the yield of phenyl isocyanate - the performance of the catalyst - 50 g phenyl isocyanate / g PdC12 per hour.

Example 4.

The carbonylation of 2 G nitrobenzene takes place under conditions wle in Example 1, at 2200C and a pressure of carbon oxide 100 atm in the presence of a catalyst with the following composition: 8.3% PdCl2 (0.02 g), 41.7% MoO3, (0.10 g), 8.5% Nb2O5 (0.02 g), 41.7% pyridine (0.10 g).

The conversion of nitrobenzene is 90%, the yield of phenyl isocyanate is 80%, the performance of the catalyst - 35 g of phenyl isocyanate / g of PdC12 per hour.

Example 5.

The carbonylation of 2 g of nitrobenzene takes place under conditions as in Example 1, at 2000C, a pressure of carbon oxide 100 at in the presence of a catalyst with the following composition: 6.8% PdC12 (0.03 g), 45.5% MOO3 (0.20 g), 2.2% Nb2 OS (0.01 g), 45.5% pyridine (0.20 g).

The conversion of nitrobenzene is 100%, the yield of phenyl isocyanate - 95%. The performance of the catalyst -32 g phenyl isocyanate / g PdCl2 per hour example 6th

The carbonylation of 2 g of p-nitrotoluene takes place under conditions as in Example 1, at 2000C and a pressure of carbon oxide 100 atm in the presence of a catalyst with the following composition: 5.6% PdCl2 (0.03 g), 18.5% MoO3 (0.10 g), 1.8% Nb2O5 (0.01 g), 47.1% pyridine (0.40 g). The conversion of the nitro compound amounts to 100%, the yield of P -Tolyliso yanat - 92%.

The performance of the catalyst - 31 g isocyanate / g PdOl2 per hour.

Example 7.

The carbonylation of 2 g of p-nitrotoluene takes place under conditions as in Example 1, at 21,000 and a pressure of carbon oxide 100 at in the presence of a catalyst with the following composition: 8.3% PdC12 (02 g), 41.7% MoO3 (0.10 g), 8.3% Nb205 (0.02 g), 41.7% pyridine (0.10 g). The conversion of the nitro compound is 100%, the yield of p-tolyl isocyanate - 80 ». The performance of the catalyst - 32 g isocyanate / g PdC12 per hour.

Example 8.

The carbonylation of 2 g of nitrobenzene takes place under conditions as in Example 1 at 2200C and a pressure of carbon oxide 50 atm in the presence of a catalyst with the following composition: 4.6% PdCl2 (0.02 g), 46.5% MoO3 (0.20 g), 2.4% NbO5 (O, Ul g), 46.5% pyridine (0.20 g).

The conversion of nitrobenzene is 81%. The yield of phenyl isocyanate - 72%. The output - 30 g phenyl isocyanate / g PdCl2 per hour.

Example 9. (for comparison).

The carbonylation of 2 g of nitrobenzene takes place under conditions as in Example 1, at 21,000 and a pressure of 100 atmospheres in presence a catalyst with the following composition: 14.3% PdCl2 (0.1 g), 28.6% MoO3 (0.2 g), 57.1% pyridine (0.4 g) (a metal oxide of Group V B is missing). Conversion of nitrobenzene 10048, yield of phenyl isocyanate - 34%, Catalyst output 3.4 g phenyl isocyanate / g PdC12 per hour.

Example 10. (for comparison).

The carbonylation of 2 g of nitrobenzene takes place under conditions as in Example 1, at 220.degree. C. and a pressure of carbon oxide 10) at in the presence of a catalyst with the following composition: 4.5% PdCl2 (0.01 g), 91.0% MoO3 (0.2 g), 4.5% Nb2O5 (0.01 g) (pyridine missing).

Conversion of nitrobenzene - 28%, yield of phenyl isocyanate - 10% performance of the catalyst - 2.8 g phenyl isocyanate / g PdCl2 per hour.

Example 11. (for comparison).

The carbonylation of 2 g of nitrobenzene takes place under conditions as in Example 1, at 2000C and a pressure of carbon oxide 100 atm in the presence of a catalyst with the following composition: 48% PdO, 48% MoO3, 4% MgO.

Conversion of the nitro compound - 4oVo, yield of phenyl isocyanate - 30% performance of the catalyst - 7 g phenyl isocyanate / g PdO per hour.

Example 12.

An autoclave with a capacity of 0.15 1 is equipped with a catalyst of the following composition: 4.8 wt% PdCl2 (0.02 g), 47.6% by weight of V2O4 (0.2 g), 23.8% by weight of WO3 (0.1 g) in 10 ml of chlorobenzene were added 1.2 g p-chloro @ nitrobenzene is added, then the autoclave is blown through with carbon oxide, Its pressure up to 150 at t: pastes and the mixture is heated at 220 ° C for two hours. After cooling to 18-20 ° C, the liquid products are separated from the residue and analyzed with the aid of gas-liquid chromatography. Conversion of the p-chloronitrobenzene-98%, Yield of p-chlorophenyl isocyanate - 84%, performance of the catalyst - 25 g isocyanate / g PdC12 per hour.

Example 13.

The carbonylation of 1.2 g of m-chloronitrobenzene takes place under conditions as in example 12, but in the presence of a catalyst with the following composition: 15% PdC12 (0.1 g), 7.5% V204 (0.05 g), 1.5% WO3 (0.01 g), 76% pyridine (0.5 g), the The reaction takes place at 220.degree. C. and a carbon oxide pressure of 50 at. The conversion the nitro compound - 100%, yield of m-chlorophenyl isocyanate - 89%, performance of the Catalyst 10 g isocyanate / g PdCl2 per hour.

Example The carbonylation of 2 g of p-chloronitrobenzene takes place under Conditions as in Example 12, in the presence of a catalyst with the following Composition; 14.8% PdC12 (0.08 g), 27.8% V2O4 (0.15 g), 1.9% WO3 (0.01g), 55.5% pyridine (0.3g), be 210 cc and a pressure of carbon oxides 100 at. conversion of the nitro compound - 100%, yield of p-chlorophenyl isocyanate- 96%, Performance of the catalyst -12 g isocyanate / g PdCl2 per hour. Example 15 The carbonylation of 2 g of o-chlorobenzene is carried out under conditions as in Example 12 in the presence of a catalyst with the following composition: 14.3.6 PdCl2 (0.05 g), 14.3% V2O4 (0.05 g), 14.3% WO3 (0.05 g), 57.1% pyridine (0.2 g), at 2100C and a pressure of Chlorine oxide 100 at. Conversion of the nitro compound -100%, yield of o-chlorophenyl isocyanate - 95%, performance of the catalyst - 19 g isocyanate / g PdCl2 per hour.

Example The carbonylation of 2 g of m-chloronitrobenzene takes place under Conditions as in Example 12 in the presence of a catalyst with the following composition: 14.3% PdC12 (0.05 g) 14.3% V204 (0.05 g), 14.3% WO3 (0.05 g), 57.1% pyridine (0.2 g), at 2050C and a pressure of carbon oxide 100 at. Conversion of the nitro compound - 100%, yield of m-chlorophenyl isocyanate - 80%, performance of the catalyst 16 g Isocyanate / g PdC12 per hour.

Example 1?.

The carbonylation of 2 g of p-chloronitrobenzene takes place under conditions as in example 12, in the presence of a catalyst as in example 15, at 2000C and a pressure of carbon oxide 100 at. Conversion of the nitro compound - 100% yield of p-chlorophenyl isocyanate - 92%, performance of the catalyst - 18 g isocyanate / g PdC12 per hour.

Example 18.

The carbonylation of 2 g of 3,4-dichloronitrobenzene takes place under conditions as in example 12 in the presence of a catalyst as in example 15 at 2000C and a pressure of carbon dioxide 100 at. The conversion of the nitro compound - 100%. Yield of 3 14-dichlorophenyl isocyanate -66%, performance of the catalyst - 11 g isocyanate / g PdC12 per hour.

Example 19.

The carbonylation of 2 g of 3,4 dichloronitrobenzene takes place under conditions as in example 12 in the presence of a catalyst with the following composition: 14.3S PdCl2 (0.05 g), 14.3 »V205 (0.05 g), 14.3 * WO3 (0.05 g), 57.1% pyridine (0.2 g), at 205 ° C. and a pressure of carbon oxide 100 at. The conversion of the nitro compound - 100%, yield of 3,4-dichlorophenyl isocyanate - 70%, performance of the catalyst - 13 g isocyanate / g PdC12 per hour.

Example 20.

The carbonylation of 2 m-chloronitrobenzene takes place under conditions as in example 12 in the presence of a catalyst as in example 19, at 210.degree and a pressure of the carbon oxide 100. Conversion of the nitro compound - 100%, yield of m-chlorophenyl isocyanate - 90%, capacity of the catalyzer - 18 g isocyanate PdCl2 per hour.

Example 21.

The carbonylation of p-chloronitrobenzene takes place under conditions as in Example 12, in the presence of a catalyst with the following composition: 14.3% PdCl2 (0.05 g), 14.3% V2O5 (0.05 g), 14.3% WO3 (0.05 g), 57.1% pyridine (0.2 g), at 220 ° C. and a pressure of carbon oxide 100 at. Conversion of the nitro compound - 100%, yield of p-chlorophenyl isocyanate- 93%, performance of the catalyst 19 g Isocyanate / g PdCl2 per hour.

Example 22.

The carbonylation of 2 g of p-chloronitrobenzene takes place under conditions as in general example 12, in the presence of a catalyst with the following composition: 14.8 »PdCl2 (0.08 g), 27.8% V2O5 (0.15 g), 1.9% WO3 (0.01 g), 55.5% 3,5-dimethylpyridine (0.3 g), at 2050C and a pressure of carbon oxide 100 at. Conversion of the nitro compound - 100%, yield of p-chlorophenyl isocyanate - 97%, performance of the catalyst - 12.1 g isocyanate / g PdCl2 per hour.

Example 23.

The carbonylation of 2 g of p-chloronitrobenzene takes place under conditions as in Example 12, in the presence of a catalyst with the following composition: 14.3% PdCl2 (0.05 g), 14.3% V2O4 (0.05 g), 14.3% WO3 (0.05 g), 57.1% 4-methylpyridine (0.2 g), at 21,000 and a pressure of carbon oxide 100 at. Conversion of the nitro compound 100%, yield of p-chlorophyl isocyanate - 97%, performance of the catalyst - 19 g Isocyanate / g PdCl2 per hour.

Example 24.

The carbonylation of 2 g of @ -chloronitrile benzene takes place under conditions as in example 12 in the presence of a catalyst with the following composition: 14.3% PdCl2 (0.05 g), 14.3% V2O5 (0.05 g), 14.3% WO3 (0.05 g), 57.1% 4-ethylpyridine (0.2 g), at 210 ° C and a pressure of carbon 100 at. Conversion of the nitro compound - 100%, yield of o-chlorophenyl isocyanate - 96% performance of the catalyst - 19.2 g Isozyana / g PdCl2 per hour.

Example 25.

The carbonylation of 2 g of p-Chlornltrobenzol takes place under conditions as in example 12 in the presence of a catalyst with the following composition: 14.3% PdCl2 (0.05 g), 14.3% V2O4 (0.05 g), 14.3% WO3 (0.05 g), 57.1% 2-methylpyridine (0.2 g), at 21000 and one pressure of carbon oxide 100 at. conversion the nitro compound -100%, yield of p-chlorophenyl isocyanate 91%, performance of the Catalyst - 18 g isocyanate / g PdC12 per hour.

Example 26 (for comparison) The carbonylation of 2 g of o-chloronitrobenzene takes place under conditions as in Example 12 in the presence of a catalyst the following composition: 25% PdCl2, 50% WO3, 25% pyridine, at 2000C and one Pressure of carbon oxide 200 at. Conversion of the nitro compound - 30% yield of O-chlorophenyl isocyanate - 26%, performance of the catalyst - 5.2 g isocyanate / g PDCl2 per hour.

Example 27 (for comparison) The carbonylation of p-chloronitrobenzene takes place under conditions as in Example 12, in the presence of a catalyst with the following composition: 25% PdCl2, 50% V205, 25% pyridine, at 2200C and one Pressure of the Soblenoxide 100 at. Conversion of the nitro compound - 100%, yield on p-chlorophenyl isocyanate - 297c, performance of the catalyst - 5.6 g isocyanate / g PdC12 per hour.

Example 28 (for comparison) The carbonylation of m-chloronitrobenzene takes place under conditions as in Example 12, in the presence of a catalyst with the following composition: 17% PdCl2, 50% V205, 33% WO3, at 2100C and one Pressure of the carbonocide 100 at. Conversion of the nitro compound - 215, yield on m-chlorophenyl isocyanate - 16%, performance of the catalyst - 3.2 g isocyanate / g PdCl2 per hour.

Example 29 (for comparison) The carbonylation of p-chloronitrobenzene takes place under conditions as in example 12, in the presence of a catalyst: PdC12 + acetonitrile (1:10), at 220 ° C and a carbon oxide pressure of 150 at. Conversion of the nitro compound - 0%, yield of isocyanate - 0%.

Claims (2)

Institute organitscheskoj chimii imeni N.D. Zelinskogo Akademii Nauk SSSR Dzerzhinsky branch of Gosudarstvennogo nautschno-issledovatelskogo i proektnogo instituta azotnoJ promyschlennosti i produktov organitscheskogo sinteza Moskobskij chimiko-technologicheskij institute imeni D.I. Mendeleeva CATALYST FOR SYNTHESIS AROMATIC MONOISOCYANATE Patent claims 1. Catalyst for the synthesis of aromatic Monoisocyanate, the palladium chloride and a metal oxide of V. Group B of the periodic table the elements contains, d u r c h g e -k e n n n n z e i c h n e t, that he is additionally a metal oxide of VI. Group B of the periodic table and pyridine or an alkyl substituted one Contains pyridine, the content of the components mentioned (in% by weight) being as follows is: Palladium chloride 1.64 - 16.6 metal oxide of group B 0.16 - 47.6 metal oxide the VI. Group B 1.5 - 81.8 pyridine or an alkyl-substituted pyridine all the rest until it is filled to 100. 2. Catalyst according to claim 1, d a d u r c h g e -k e n n z e i c Note that the catalyst components are dehydrated and mixed in a solvent became.