RU1784039C - Process for producing benzoic acid derivatives - Google Patents

Description

1

(21) 4356294/04

(22) 07.22.88

(46) 12/23/92. Bull. Number 47

(31) 83293

(32) 07.23.87

(33 IS

(71) Gedot Petrochemical Industries Ltd., Jissum Research and Development Company of Dze and Hebrew University of Jerusalem (IS)

(72) Yihad Dhaka, Amikam Zoran, and Yoel Sasson (IS)

(56) German Patent No. 1263003,

class C 07 C 51/265, olublik. 1974.

US patent No. 4007228, cl. C.07 C 51/265, published. 1981.

UK patent No. 1005315, CL C 07 C 51/16, published. 1968. (54) METHOD FOR PRODUCING BENZOIC ACID DERIVATIVES

(57) Summary of the invention: the product is p-chlorobenzoic acid BF CyHsOaCf. Purity 99%. The product is anisic acid BF CaNeO3. Purity 98%. The product is toluic acid BF CsHe02. Purity 96%. The product is p-nitrobenzoic acid StnzOzM. Purely, that is 100%. Diphenylcarboxylic acid product The invention relates to an improved process for the preparation of benzoic acid derivatives, in particular, to a simple process for the preparation of benzoic acid derivatives in high yield and high purity from toluene derivatives. A known method for the production of p-toluic acid by oxidation of p-xylene with an oxygen-containing gas in the presence of a catalyst - salts of the Quaternary phospholite CisHio02. Purity 92%. Reagent 1: toluene derivative of the formula R-f-CH3 R-CH3, Hal, N02, Ph, OCH3. Reagent 2; air. Reaction conditions: at 130-170 ° C and high pressure, phase exchange catalyst. comprising a) a quaternary onium salt of the formula

t

1

-gX

RirY- a

b.

where RI is al kil; R2, Ra, R4 may have the same or different meanings and be selected from alkyl with a total number of atoms, carbon 18-48; Y, - nitrogen or phosphorus / selected from the number of SG, Br. with the proviso that when B g is absent in the system, bromide or bromine is added; c) a salt of a metal selected from the group of transition metals Co, Ml, Mo, V, Cg with a molar ratio a: b of 0.4-1.15: 1, respectively; traces of a polar solvent capable of solubilizing the catalyst, using crystallization water; solvent, which is used as the initial toluene derivative. 1 s etc. pr., 1 tab.

nor in acetic acid medium, taken in a 0-fold amount with respect to the p-th: ilol. The yield does not exceed 30-70%.

A known method of producing p-nitrobenzoic acid by oxidation of p-nitrotoluene with oxygen in acetic acid in the presence of a cobalt salt and a bromide compound (for example, KBr, NaBr, NH4Brj as catalysts, the amount of acetic acid being in the range of 3 C / 1

with

h

00

Ј O CJ O

with

15 mol per mol of p-nitrotoluene. By carrying out the process in this way, a colorless n-nitrobenzoic acid is obtained with a conversion of 92-93% of the calculated product.

The closest to the invention in technical essence and the achieved result is a method for producing derivatives of benzoic acid, for example p-toluic acid, by oxidizing the corresponding toluene derivative with air in the presence of a catalyst containing a transition metal salt at 140 - 300 ° C and partial pressure oxygen from 2.0 atm and above. The catalyst is prepared by heating the cobalt salt or cobalt oxide in a dry state at 200-800 ° C. About 60% of xylene is converted to p-toluene acid.

A disadvantage of the known method is that with the comparative complexity of this process, it does not allow to obtain the target product in high yield and high conversion.

The purpose of the invention is to increase the conversion of the process.

This goal is achieved in that according to the method of producing derivatives of benzoic acid of the formula

Roccooh

where R-CH3, Hal, NOa, Ph, OCH3, by liquid-phase oxidation of the corresponding toluene derivative with air at a temperature of 130-170 ° C and a partial oxygen pressure of 2.0 atm and above in the presence of a catalyst, the phase exchange catalyst is used as the latter, including - tea

a) Quaternary onium salt of the formula

SC

.

X

where RI is alkyl; 50

R2, Bz, R4 may have the same or

various values and be selected from alkyl with a total number of carbon atoms of 18 48;

Y is nitrogen or phosphorus; 55

X is selected from the series SG, Br, HSCM at

provided that when B g is absent in the system,

bromide or bromine is added;

c) a salt of a metal selected from the group

transition metals Co Mn Mo V Cg, at

0 5

0

5

0

fifty

5

0

5

a molar ratio a: in 0.4 - 1.15: 1, respectively, and the process is carried out in the presence of traces of a polar solvent capable of solubilizing the catalyst, which uses crystallization water, and in a solvent medium, which uses the initial toluene derivative, followed by isolation of the product, if necessary, by the reaction mass after cooling, which allows to increase the conversion of the process.

Usually use a quaternary ammonium salt obtained directly in the process,

Typical examples of quaternary onium salts suitable for use are quaternary ammonium bromides or chlorides, as well as quaternary phosphonium bromides or chlorides.

It was found that the iodides of the quaternary onium salts are mainly ineffective as phase transfer catalysts in the implementation of this method. In all likelihood, in the presence of a transition metal salt, the catalytic activity of the quaternary phosphonium iodide changes significantly. This is illustrated by Example 18, where Quaternary phosphonium iodide is used under the same conditions as those of the present process.

The transition metal used in the catalytic system is selected from the group of the following metals, manganese, cobalt, molybdenum, chromium, vanadium.

The transition metal salt has a hydrated form containing crystallization water.

The anion to which the yellow metal is bound is not critical, and may be selected from chloride or bromide, provided that the corresponding salt can be solubilized in the reaction system.

The oxidation can be carried out with pure gaseous oxygen or, preferably, a gas mixture containing lower concentrations of oxygen, for example air.

The phase transfer catalyst plays an important role in the implementation of this method.

It has been found that the heavy metal salt is solubilized in the organic phase in the form of an onium addition product. Thus, it catalyzes the oxidation reaction.

The quaternary onium salt may be added as such or prepared directly in the process zone in the case of, for example, the use of ammonium salt by introducing a quaternary amine and an alkylating reagent into the reaction system.

In order to initiate a reaction, the method should include introducing trace amounts of a polar solvent, for example, negligible amounts of water, which is preferably present in the metal salt in the form of crystallized water. The amount of polar solvent should be sufficient to dissolve the metal salt to a saturated solution under the given reaction conditions. It was found that an increase in the amount of water in the system leads to a decrease in the reaction rate; this should usually be ruled out.

The process according to the invention is characterized by a high product yield, usually reaching more than 90% and even more than 99%. The resulting benzoic acid derivatives are essentially a pure product containing only minor amounts of by-products. Thus, additional cleaning steps for some applications are significantly reduced.

The process is carried out at a temperature of 130-170 ° C and elevated pressure, usually in the range of about 10-25 atm, corresponding to a partial oxygen pressure in the range of 2-5 atm.

The process is carried out in the presence of a solvent. The solvent should be inert under the reaction conditions. The solvent may be a toluene derivative, a reagent used as a starting material; in this case, this toluene derivative should be separated from the final product and recycled to the process zone again.

This process is generally simple to implement and requires standard equipment that is commonly used for this type of reaction. The reactor consists of an autoclave equipped with a stirrer and a condenser. The autoclave has a jacket through which heated oil or chilled water circulates, the temperature being controlled by a thermostat. Gaseous reactants are introduced through a switchgear and exhaust gases are passed through a needle valve and a flow meter. Chemicals: toluene derivative, transition metal salt and phase transfer catalyst, are fed into the reaction vessel, followed by air. This vessel is heated to a temperature of about 130 ° C. as a result

a pressure increase of up to about 15 atm can be achieved. After the start of the reaction, the temperature rises to about 160 ° C. The vapors containing 5 toluene derivative and water are condensed, the toluene derivative is recycled again while water is removed from the reaction system. After 2-3 hours at a continuous flow of air

0 the temperature decreases, indicating the end of the reaction. Further processing of the reaction products can be carried out in two different ways.

If necessary, the reaction product is distilled in vacuo. The residual distillate does contain a catalyst and can be recycled to a further oxidation cycle of the toluene derivative. Thus, the catalyst can be used repeatedly, i.e., it can, for example, be removed together with the oxidation product, removed from the reactor and used again in the oxidation process.

It is possible to introduce an aqueous-alkaline solution (15-30 wt.%) Into the chilled reaction product. The resulting filtrate is treated with a concentrated acid solution, preferably inorganic, whereby the precipitated benzoic acid derivative is separated. This process can be carried out continuously.

Example 1. The equipment used consists of an autoclave (1 l) equipped with

5 a jacket and a thermostat with oil circulation, a magnetic stirrer, a water-cooled condenser and a liquid separator, a distributor for introducing gaseous reagents, an exhaust device for venting gas with a needle valve and a flow meter and a sampling valve.

180 g of p-chlorotoluene, 5 g of cobalt chloride hydrate and 6.4 g of bromide 5 and tetrahexylammonium are introduced into the reactor. The mixture is heated to about 137 ° C. under an oxygen pressure of 7.5 atm. The reaction is continued for about 5 hours, while the temperature rises to about 160 ° C. After cooling, p-chlorobenzoic acid was determined in an amount of 220.6 hours. Yield 92 wt.%. The product purity is 99% by weight.

Example 2. In the reactor used in example 1, was introduced 239 g of m-xylene, 1.1 g

5 cobalt chloride hydrate and 1.3 g of didecyldimethylammonium bromide. The mixture is heated to approximately 130 ° C under an air pressure of .15 atm (speed 6 l / min). The reaction continues for about 4 hours, while the temperature rises to 160 ° C. Conversion process 90% (GISH). 267.1 g of m-toluic acid are obtained. Yield 99%. Acid is isolated by distillation of the reaction mass in a yield of 97 wt.% With a purity of 99 wt.%.

Sample 233 g of o-xylene (2.25 mol), 1.07 g of cobalt chloride hexahydrate (4.5 mmol) and 1.8 g of tetraoctylammonium bromide (3.3 mmol) were introduced into the reactor used in example 1 . The autoclave is heated to a temperature of about 135 ° C, with a pressure of (air) of about 10 atm. Air is passed at a speed of 2.0 l / min (at normal temperature and pressure). The reaction mixture is heated, the temperature reached 170 ° C, is maintained for about 3 hours. After cooling, the mixture is subjected to vacuum distillation (about 20 mmHg), and 284 g of pure o-toluic acid are obtained (yield.%) .

Example 4, The process was carried out as in example 3 using exactly the same amounts of starting reagents and under the same conditions, with the exception of replacing o-xylene with m-xylene. The amount of the obtained product - m-toluic acid 281.5 g (yield 92 wt.%).

Example 5. The process is carried out as in example 3 using exactly the same amounts of starting reagents and under the same reaction conditions, with the exception of replacing o-xylene with p-xylene. The resulting product will be 294 g of pure p-toluic acid (yield 96 wt.%).

Example 6. The process is carried out as in Example 1. The starting reagents are introduced: 252 g of 4-p-chlorotoluene (2.25 mmol); 1.02 g of cobalt chloride hexahydrate (4.5 mmol) and 1.64 g of tetraoctylammonium b-romide (3 mmol).

The autoclave is heated to about 140 ° C, with an air pressure of 15 atm. Air is passed at a speed of 2.0 l / min (at normal temperature and pressure). After the start of the reaction, the temperature rises to about 162 ° C. After 3 hours, the temperature drops to 140 ° C, which indicates the end of the reaction. After cooling, the mixture was distilled in vacuo (20 mmHg). The result is 330.9 g of pure 4-chlorobenzoic acid (yield May 94,%).

Example 7. The process is carried out as in example 1. The starting reagents are introduced: 308 g of 4-nitrotoluene (2.25 mmol), 2.14 g of cobalt chloride hexahydrate (9.0 mmol) and 2.6 g of tetrahexylammonium bromide (6 mmol) ) Air is introduced into the autoclave at a pressure of 20 atm. After heating the reaction mixture to about 150 ° C, air is passed from the autoclave at a rate of 2 l / min (at normal temperature and pressure). The reaction mixture is heated as such.

to a temperature of about 170 ° C, and this temperature is maintained for about 4 hours. After cooling, the mixture is analyzed. A 100% yield of product containing 46 mol of pure 4-nitrobenzoic is obtained.

0 acid in 4-nitrotoluene (54 mol%), serving as a solvent of the reaction medium. 4-Nitrotoluene is separated and recycled back to the oxidation step.

Example 8. The process is carried out by

5 of Example 7, under the same reaction conditions and using the same chemicals, but 2.6 g of tetrahexylammonium bromide is replaced with 3.3 g of tetraoctylammonium bromide (6 mmol). Final mix

0 contains 42 mol% of pure 4-nitrobenzoic acid in 4-nitrotoluene (58 mol%), which serves as a solvent for the reaction medium. 4-Nitrotoluene is separated and recycled again to the oxidation step

5 (achieved overall product yield of 100%).

Example 9. The process is carried out as in example 1, while introducing the following starting reagents: 382.5 g of p-methyldiphenyl

0 (2.25 mol), 1.07 g of cobalt chloride hexahydrate (4.5 mmol) and 0.2 g of didecylammonium bromide. The autoclave is heated to a temperature of about 140 ° C and air is introduced at a pressure of about 10 atm. Air is blown through at a speed of 2 l / min (at normal temperature and pressure). After the start of the reaction, the temperature rises to 165 ° C. After 3 hours at this temperature, stirring is stopped. After cooling, the mixture was distilled in vacuo (20 mmHg). Obtain 414 g of pure p-phenylbenzoic acid (yield 92 wt.%).

Example 10. The process is carried out by

5 of Example 1. The following starting reagents are introduced: 378 g of 2-methylbiphenyl, 1.1 g of cobalt chloride hydrate and 1.3 g of didecy lammonium bromide.

The autoclave is heated to a temperature of about 140 ° C and air is introduced at a pressure of about 20 atm. Air is passed at a rate of 2 l / min (at normal temperature and pressure).

After the start of the reaction, the temperature of lo5 rises to about 160 ° C. After 4 hours at this temperature, stirring is stopped. After cooling, the mixture was analyzed. Found that it contains 396 g of diphenyl-2-carboxylic (o-phenylbenzoic) acid (yield 89 wt.%),

Example 11. The process is carried out as in Example 1. The following chemicals are introduced: 238.5 g m-xylene, 5.6 g chromium hexahydrate (21 mmol) and 9 g didecylammonium bromide (22.5 mmol). The autoclave is heated and, with stirring, for about 5 hours at a temperature of 150 ° C, air is introduced at a pressure of the order of 16 atm with a constant flow rate of 2.3 l / min.

After cooling, the mixture was analyzed. It was found that it contains 257 g of m-toluic acid (yield 84 wt.%).

Example 12. The process is carried out as in Example 1. The following starting reagents are introduced: 238.5 g of o-xylene, 2.2 g of cobalt bromide hexahydrate (6.7 mmol) and 2.23 g of tetra-p-hexylammonium acid sulfate. The autoclave is heated with stirring for 5 hours to a temperature of about 150 ° C and under an air pressure of about 20 atm, introduced into the autoclave with a constant α-velocity of 3 l / min. After cooling, the mixture was distilled in vacuo. Obtain 281 g of o-toluic acid (yield 91.8%) with a purity of 99%.

Example 13. The process is carried out as in example 1. The following starting reagents are introduced: 284.6 g of p-chlorotoluene, 1.6 g of cobalt chloride hexahydrate (6.7 mmol) and 3.29 g of tetra-p-decylammonium bromide ( 5 mmol)

The autoclave is heated with stirring of its contents to a temperature of the order of 155 ° C for 6 hours with the introduction of air at a pressure of 20 atm, passed at a constant speed of 3 l / min. After cooling, the mixture was distilled in vacuo. Obtain 318 g of p-chlorobenzoic acid (yield 90.3%) with a purity of 99.9%.

Example 14. The process is carried out as in Example 1. The following starting reagents are introduced: 424.25 g of p-bromotoluene, 1.6 g of cobalt chloride hexahydrate (6.7 mmol) and 2.25 g of tetrahexylphosphonium bromide. The autoclave is heated with stirring of its contents to a temperature of 170 ° C for 6 hours with the introduction of air at a pressure of 17 atm, passed at a speed of 2.2 l / min. After cooling, the reaction mixture was analyzed by gas chromatography. It was found that p-bromtoluene is selectively and completely converted to p-bromobenzoic acid, obtained in an amount of 454.5 g. The purity is 100%.

Example 15. The process is carried out analogously to example 1. 0.82 g of p-hexyl bromide

and 1.38 g of tri (n-hexyl) amine was dissolved in 10 g of p-methoxytoluene. The solution was introduced into the autoclave together with 264.5 g of p-methoxytoluene and 1.6 g of cobalt chloride hexahydrate (6.7 5 mmol). The mixture is heated and stirred at a temperature of 140 ° C for about 9 hours and an air pressure of 15 atm (with a flow rate of 2 l / min). After cooling, the reaction mixture contains 335.2 g of p-anisic 0 acid of 99% purity and 2% of anisaldehyde.

Example 16. The process is carried out as in example 1, The following starting reagents are added: 238.5 g of o-toluene, 2.2 g of hexahydride

5 cobalt bromide (6.7 mmol) and 2.38 g of tetra-p-hexylammonium benzoate (5 mmol).

The autoclave is heated with stirring of its contents for about 6 hours at 160 ° C under an air pressure of 16 atm.

0 (skipped at a speed of 2 l / min). After cooling, the mixture was distilled in vacuo to give 278.5 g of o-toluic acid (91% yield) with a purity of 99.1%. Example 17. The process is carried out on

5 of Example 1. The following reagents are introduced: 284.6 p-chlorotoluene, 1.6 g of cobalt chloride hexahydrate and 2.5 g of tetrahexylammonium bromide. The contents of the reactor were stirred for 6 h at a temperature of 155 ° C, an air pressure of 50 atm, and a volumetric flow rate of 1.7 l / min. After cooling, this mixture was distilled under vacuum to yield 315 g (89% yield) of p-chlorobenzoic acid with a purity of 99.5%.

Example 18. The process is carried out as in example 11. The following reagents are introduced into the autoclave: 382.5 g (2.25 mmol) of p-methylbiphenyl, 1.2 g (3 mmol) of didecyldimethylammono bromide (DDAB) (a) 2.3 g (7 mmol) of CoCl-6H20 (c) (ratio a: 0.43). The autoclave is heated to a temperature of about 140 ° C at an air pressure of about 20 atm. The result is 400.5 g of p-fe5 nylbenzoic acid (89% yield) with a purity of 98% (GLC).

Examples 19-21, o-Toluylic acid, m-toluic acid and p-toluic acid are obtained from 238.5 g (2.25 mmol)

0, respectively, o-, m-, and p-xylene using DDAB (a) and CoCl2 6H20 (c) in accordance with the present invention. Amounts of DDAB, metal salts used and ratios: in the following5 2.3 g (7 mmol) of CoC1a-bH20, 2.8 g of DDAB

(7 mmol); a: in 1; 5.6 g (21 mmol) of CoClz hbNaO; 5.6 g of DDAB (14 mmol); a: 0.667, 2.3 g (7 mmol) CoCl2-6H20, 1.4 g DDAB (3.6 mmol); a: at 0.5, Reaction conditions are similar to those described respectively in

examples 3-5. As a result, the following products were obtained: 284.6 g of o-toluic acid (93% yield) with a purity of 98%; 275.6 g m-toluic acid (90% yield) with a purity of 99%; 263.2 g of p-toluic acid (86% yield) with a purity of 97%.

In all the examples given, the products were isolated by distillation.

PRI me R 22-24. Toluic acid was prepared under the conditions of Example 3 using 238.5 g of m-xylene (2.25 mmol), 5.6 g of DDAB (7 mmol) and 7.1 g of transition metal salt (c), which was selected from the group : (I), or MbCl2 4H20 (II), or Mode x хЗН20 (1М).

The amounts of the indicated metal salts (7.1 mmol), the ratios between the components of the catalyst (a: c), the product yields and their purity are indicated in the table.

Example 25 (comparative). The process is carried out as in Example 1. The following starting reagents are introduced: 238.5 g of p-xylene (2.25 mol), 1.6 g of cobalt chloride hexahydrate and 1.6 g of tetra-n-Cheutylammonium bromide (5 mmol).

The autoclave is heated for about 5 hours at a temperature of 140 ° C under an air pressure of 15 atm (passed at a speed of 2 l / min). After cooling, the mixture was analyzed. It was found to contain less than 5% ji-toluic acid, the remainder being unreacted paraxylene.

Example 26 (comparative). The process is carried out as in Example 1. The following starting reagents are introduced: 238.5 g of m-xylene (2.25 mmol), 1.6 g of cobalt chloride hexahydrate (6.7 mmol) and 2.45 g of tetra-n- iodide hexylphosphonium (5 mmol). The autoclave is heated and its contents are stirred for about 6 hours at a temperature of 160 ° C under an air pressure of 20 atm (passed at a speed of 3 l / min). After cooling, the mixture was analyzed. It was found that it contains less than 10% m-toluene acid.

Claims (2)

The claims 1. The method of obtaining derivatives of benzoic acid of the formula 0-soon 0 5 0 5 0 5 where RI is alkyl; where R is CH3; Hal; N02; Ph, OCH3, by liquid phase oxidation of the corresponding toluene derivative with air in the presence of 0 catalyst containing a transition metal salt at 130-170 ° C and elevated pressure, characterized in that, in order to increase the conversion of the process, a phase exchange catalyst is used as a catalyst, including: a) Quaternary onium salt of the formula  K. RI .Y Nl R3 R2, R3. R4 may have the same or different meanings and may be selected from alkyl with a total number of carbon atoms of 18-48; Y is nitrogen or phosphorus; X is selected from CH, BrjHSt 4, provided that when Br is not present in the system, bromide or bromine is added; c) a salt of a metal selected from the group of transition metals Co, Mn, Mo, V, Cr, with a molar ratio a to 0.4 - 1.15: 1, respectively, as well as in the presence of traces of a polar solvent capable of solubilizing the catalyst , which is used as crystallization water, in a solvent medium, which is used as the initial toluene derivative, followed by isolation of the product, if necessary, by distillation of the reaction mass after cooling. 2. A method according to claim 1, characterized in that a quaternary ammonium salt obtained directly in the process is used.