Synthesis of Benzoyl Cyanide Catalyzed by Composite Phase Transfer Catalyst

Abstract

The present invention relates to the technical field of pesticide formulations and proposes a composite phase transfer catalyst-catalyzed method for synthesizing benzoyl cyanide, comprising the following steps: S1, adding sodium cyanide and cuprous cyanide to xylene, and azeotropically dehydrating the mixture to obtain an azeotrope; S2, adding acetonitrile to the azeotrope, dehydrating the mixture, and then adding a phase transfer catalyst and benzoyl chloride to react to obtain benzoyl cyanide. This technical solution solves the problem that the synthesis of benzoyl cyanide from sodium cyanide and benzoyl chloride requires harsh reaction conditions and a low reaction yield.

Description

Technical Field

[0001] The present invention relates to the technical field of pesticide preparations, and in particular to the synthesis of benzoyl cyanide by a composite phase transfer catalyst catalytic method. Background Art

[0002] Benzoyl cyanide is a kind of important fine chemical intermediate, be widely used in the synthesis of agricultural chemicals and medicine, benzoyl cyanide of the prior art has multiple synthesis method, method commonly used in the current prior art has benzoyl chloride and benzoic anhydride and sodium cyanide reaction method, dimethylamine catalysis hydrocyanic acid reaction method, sodium cyanide and benzoyl chloride reaction method to produce, but all there is reaction temperature higher, long reaction times in above-mentioned reaction method, and then cause the problem that benzoyl cyanide synthesis yield is lower.In patent documentation CN109651192A-benzoyl cyanide novel synthesis process, adopt sodium cyanide and benzoyl chloride reaction method, add reaction catalyst and phase-transfer catalyst simultaneously, the phase-transfer catalyst wherein used is common known phase catalyst, and there is catalytic efficiency low, and then cause the defect that the synthesis yield of benzoyl cyanide is low.Therefore, adopt and prepare gentle reaction conditions, the method for the benzoyl cyanide of higher yield is extremely important. Summary of the Invention

[0003] The invention proposes a composite phase transfer catalyst catalytic method for synthesizing benzoyl cyanide, which solves the problems of harsh reaction conditions and low reaction yield in the related art of synthesizing benzoyl cyanide from sodium cyanide and benzoyl chloride.

[0004] The technical solutions of the present invention are as follows:

[0005] The present invention proposes a composite phase transfer catalyst catalytic method for synthesizing benzoyl cyanide, comprising the following steps:

[0006] S1, adding sodium cyanide and cuprous cyanide to xylene, and azeotropically dehydrating to obtain an azeotrope;

[0007] S2. Add acetonitrile to the azeotrope, dehydrate, and then add a phase transfer catalyst and benzoyl chloride to react to obtain benzoyl cyanide.

[0008] As a further technical solution, the molar ratio of the sodium cyanide to the benzoyl chloride is 1:1 to 1:1.5.

[0009] As a further technical solution, the added mass of the cuprous cyanide is 0.5% to 1.5% of the mass of the benzoyl chloride, and the added mass of the phase transfer catalyst is 0.2% to 0.5% of the mass of the benzoyl chloride.

[0010] As a further technical solution, in g / mL, the volume mass ratio of xylene to benzoyl chloride is 1:1 to 2:1.

[0011] As a further technical solution, the water content of the xylene is ≤250 PPm.

[0012] As a further technical solution, the mass ratio of acetonitrile to benzoyl chloride is 1:0.05 to 1:0.1.

[0013] As a further technical solution, the water content of the acetonitrile is ≤500 PPm.

[0014] As a further technical solution, the phase transfer catalyst is triethylbenzylammonium chloride and / or triethylammonium chloride.

[0015] As a further technical solution, the phase transfer catalyst is a mixture of triethylbenzylammonium chloride and triethylammonium chloride in a mass ratio of 2:1 to 3:1.

[0016] As a further technical solution, the reaction temperature is 90-130° C., and the reaction time is 3-5 h.

[0017] As a further technical solution, the phase transfer catalyst is modified by porous ceramsite.

[0018] As a further technical solution, the added mass of the porous ceramsite is 0.5% to 1% of the mass of the phase transfer catalyst.

[0019] As a further technical solution, the modification method is: adding porous ceramsite to the aqueous solution of the phase transfer catalyst, mixing evenly, and drying to obtain the modified phase transfer catalyst.

[0020] As a further technical solution, the porous ceramsite is prepared by the following method: adding the porous ceramsite to water, adding ammonium carbonate to prepare slurry, soaking the organic foam template in the slurry, drying and sintering to obtain the porous ceramsite.

[0021] As a further technical solution, the added mass of ammonium carbonate is 15% to 25% of the mass of the porous ceramsite.

[0022] As a further technical solution, the immersion temperature is 80-100° C., and the immersion time is 10-15 hours.

[0023] The working principle and beneficial effects of the present invention are:

[0024] 1. In the present invention, xylene is used as the first solvent, sodium cyanide and cuprous cyanide are added for azeotropic dehydration to obtain an azeotrope, acetonitrile is added to the azeotrope, and then a composite phase transfer catalyst is added to promote the reaction of sodium cyanide, cuprous cyanide and benzoyl chloride, thereby improving the efficiency of the catalytic reaction. The addition of the composite phase transfer catalyst also reduces the reaction temperature, shortens the reaction time and reduces the generation of reaction by-products, thereby obtaining benzoyl cyanide with a high yield.

[0025] 2. In the present invention, a highly polar acetonitrile solvent is added to the azeotrope to accelerate the reaction rate, thereby shortening the reaction time and improving the yield of benzoyl cyanide.

[0026] 3. In the present invention, the xylene reaction solvent is dehydrated, which can effectively reduce the generation of reaction by-products, avoid the easy decomposition of benzoyl chloride in contact with water, and promote the composite phase transfer catalyst to better transfer the anions in the reaction substrates sodium cyanide and cuprous cyanide from the aqueous phase to the organic phase to react with benzoyl chloride, thereby improving the yield and purity of benzoyl cyanide.

[0027] 4. In the present invention, triethylbenzylammonium chloride and triethylammonium chloride are used as composite phase transfer catalysts, which improves the catalytic reaction efficiency, shortens the reaction time, and reduces the reaction temperature and the generation of reaction by-products, thereby increasing the yield of the product benzoyl cyanide.

[0028] 5. In the present invention, the composite phase transfer catalyst is modified by porous ceramsite, which not only improves the activity of the composite phase transfer catalyst, but also increases the reaction rate, thereby increasing the yield of the product benzoyl cyanide.

[0029] 6. In the present invention, the porous ceramsite is modified simultaneously by the organic foam template and the pore-forming agent ammonium carbonate, which can increase the pores of the porous ceramsite, thereby promoting the impregnation effect of the composite phase transfer catalyst in the porous ceramsite, improving the activity of the composite phase transfer catalyst, and thus improving the yield of the product benzoyl cyanide. DETAILED DESCRIPTION

[0030] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0031] Example 1

[0032] S1. Add 1014 L of xylene to the MT-1 reactor, stir, add 353.5 kg of sodium cyanide and 5.1 kg of cuprous cyanide, heat to 150 ° C and reflux, and azeotropically dehydrate until the xylene water content is ≤250 ppm to obtain an azeotrope;

[0033] S2, the azeotrope is cooled to 90 ℃, 51kg acetonitrile is added, dehydrated to acetonitrile water content≤500PPm, heated to 95 ℃, 2kg triethylbenzyl ammonium chloride is added again, 1014kg benzoyl chloride is added dropwise in 1~1.5h, heated to 90 ℃, heat preservation 5h, sampling detection filtrate benzoyl chloride conversion is 99.8%, i.e. benzoyl chloride remaining less than 0.2% and reaction is complete, after completion of the reaction, the temperature is lowered to 40 ℃, centrifuged, filtered, filter residue is washed with 30% xylene detergent twice, collect filtrate, the filtrate is evaporated and concentrated to obtain 971kg benzoyl cyanide, the purity of benzoyl cyanide detected by high performance liquid chromatography chromatograph is 99.3%, and the yield of benzoyl cyanide is 95.3%.

[0034] Example 2

[0035] S1. Add 2028 L of xylene to the MT-1 reactor, stir, add 235.7 kg of sodium cyanide and 15.2 kg of cuprous cyanide, heat to 150°C and reflux, and azeotropically dehydrate until the xylene water content is ≤250 ppm to obtain an azeotrope;

[0036] S2, azeotrope is cooled to 90 ℃, 101kg acetonitrile is added, dehydrated to acetonitrile water content≤500PPm, warming to 95 ℃, then 3kg triethylammonium chloride is added, 1014kg benzoyl chloride is added dropwise in 1~1.5h, warming to 130 ℃, insulation 3h, sampling detection filtrate benzoyl chloride conversion is 99.8%, i.e. benzoyl chloride remains less than 0.2% and reaction is complete, after completion of the reaction, cool to 40 ℃, centrifuge, filter, filter residue is washed with 30% xylene detergent twice, collect filtrate, the filtrate is evaporated and concentrated to obtain 976kg benzoyl cyanide, the purity of benzoyl cyanide detected by high performance liquid chromatography is 99.2%, and the yield of benzoyl cyanide is 95.7%.

[0037] Example 3

[0038] The only difference between this embodiment and embodiment 1 is that in step S2, triethylbenzylammonium chloride is replaced with tetrabutylammonium bromide. Finally, 969 kg of benzoyl cyanide is obtained. The purity of benzoyl cyanide detected by high performance liquid chromatography is 99.1%, and the yield of benzoyl cyanide is 94.9%.

[0039] Example 4

[0040] The only difference between this embodiment and embodiment 1 is that in step S2, 1 kg of triethylammonium chloride is further added, and the rest is the same as in embodiment 1. Finally, 993 kg of benzoyl cyanide is obtained. The purity of benzoyl cyanide detected by high performance liquid chromatography is 99.1%, and the yield of benzoyl cyanide is 97.2%.

[0041] Example 5

[0042] The only difference between this embodiment and embodiment 1 is that in step S2, 0.8 kg of triethylammonium chloride is further added, and the rest is the same as in embodiment 1. Finally, 995 kg of benzoyl cyanide is obtained. The purity of benzoyl cyanide detected by high performance liquid chromatography is 99.3%, and the yield of benzoyl cyanide is 97.6%.

[0043] Example 6

[0044] The only difference between this embodiment and Example 1 is that in step S2, 0.7 kg of triethylammonium chloride is further added, and the rest is the same as in Example 1. Finally, 996 kg of benzoyl cyanide is obtained. The purity of benzoyl cyanide detected by high performance liquid chromatography is 99.3%, and the yield of benzoyl cyanide is 97.7%.

[0045] Example 7

[0046] The only difference between this embodiment and embodiment 5 is that in step S2, the composite phase transfer catalyst of triethylbenzylammonium chloride and triethylammonium hydroxide chloride is modified by porous ceramsite.

[0047] The preparation method of porous ceramsite is as follows: 100g of porous ceramsite is added to 200mL of water, 15g of ammonium carbonate is added to make a slurry, 100g of organic foam template is immersed in the slurry, the temperature is raised to 80℃, immersed for 15h, and dried and sintered at 500℃ to obtain porous ceramsite.

[0048] The composite phase transfer catalyst modification method comprises adding 100 g of the phase transfer catalyst to 200 mL of water, adding 50 g of porous ceramsite, mixing uniformly, and drying to obtain a modified phase transfer catalyst. The resulting product is 1014 kg of benzoyl cyanide, which has a purity of 99.1% as determined by high-performance liquid chromatography, and a yield of 99.3%.

[0049] Example 8

[0050] The only difference between this embodiment and embodiment 5 is that in step S2, the composite phase transfer catalyst of triethylbenzylammonium chloride and triethylammonium hydroxide chloride is modified by porous ceramsite.

[0051] The preparation method of porous ceramsite is as follows: 100g of porous ceramsite is added to 200mL of water, 25g of ammonium carbonate is added to make a slurry, 100g of organic foam template is immersed in the slurry, the temperature is raised to 100℃, immersed for 10h, and dried and sintered at 500℃ to obtain porous ceramsite.

[0052] The composite phase transfer catalyst modification method comprises adding 100 g of the phase transfer catalyst to 200 mL of water, adding 100 g of porous ceramsite, mixing uniformly, and drying to obtain a modified phase transfer catalyst. The resulting product is 1015 kg of benzoyl cyanide, which has a purity of 99.3% as determined by high-performance liquid chromatography, and a yield of 99.6%.

[0053] Example 9

[0054] The difference between this embodiment and embodiment 5 is that triethylammonium chloride is replaced by polyethylene glycol, and the rest is the same as in embodiment 5. Finally, 948 kg of benzoyl cyanide was obtained. The purity of benzoyl cyanide detected by high performance liquid chromatography was 99.4%, and the yield of benzoyl cyanide was 93.1%.

[0055] Comparative Example 1

[0056] The only difference between this comparative example and Example 1 is that azeotropic dehydration is not performed in step S1. Finally, 943 g of benzoyl cyanide was obtained. The purity of benzoyl cyanide determined by high performance liquid chromatography was 89.2%, and the yield of benzoyl cyanide was 83.1%.

[0057] Comparative Example 2

[0058] The only difference between this comparative example and Example 1 is that acetonitrile is not added in step S2. Finally, 904 kg of benzoyl cyanide was obtained. The purity of benzoyl cyanide detected by high performance liquid chromatography was 99.3%, and the yield of benzoyl cyanide was 88.7%.

[0059] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Synthesis of benzoyl cyanide by composite phase transfer catalyst catalysis, characterized in that, The following steps are involved: S1, adding sodium cyanide and cuprous cyanide to xylene, and azeotropically dehydrating to obtain an azeotrope; S2, adding acetonitrile to the azeotrope, dehydrating, and then adding a phase transfer catalyst and benzoyl chloride to react to obtain benzoyl cyanide; The phase transfer catalyst is a mixture of triethylbenzylammonium chloride and triethylammonium chloride in a mass ratio of 2:1 to 3:1; The phase transfer catalyst is modified by porous ceramsite; the added mass of the porous ceramsite is 0.5% to 1% of the mass of the phase transfer catalyst.

2. The composite phase transfer catalyst catalytic method for synthesizing benzoyl cyanide according to claim 1, wherein The molar ratio of the sodium cyanide to the benzoyl chloride is 1:1 to 1:1.

5.

3. The composite phase transfer catalyst catalytic method for synthesizing benzoyl cyanide according to claim 1, wherein The added mass of the cuprous cyanide is 0.5% to 1.5% of the mass of the benzoyl chloride, and the added mass of the phase transfer catalyst is 0.2% to 0.5% of the mass of the benzoyl chloride.

4. The composite phase transfer catalyst catalytic method for synthesizing benzoyl cyanide according to claim 1, wherein In mL / g, the volume mass ratio of the xylene to the benzoyl chloride is 1:1 to 2:

1.

5. The composite phase transfer catalyst catalytic method for synthesizing benzoyl cyanide according to claim 1, characterized in that: The mass ratio of the acetonitrile to the benzoyl chloride is 1:0.05 to 1:0.

1.

6. The composite phase transfer catalyst catalytic method for synthesizing benzoyl cyanide according to claim 1, characterized in that: The reaction temperature is 90-130° C., and the reaction time is 3-5 h.

7. The composite phase transfer catalyst catalytic method for synthesizing benzoyl cyanide according to claim 1, characterized in that: The modification method comprises the following steps: adding porous ceramsite to an aqueous solution of a phase transfer catalyst, mixing the mixture evenly, and drying the mixture to obtain a modified phase transfer catalyst.

8. The composite phase transfer catalyst catalytic method for synthesizing benzoyl cyanide according to claim 1, characterized in that: The porous ceramsite is prepared by the following method: adding the porous ceramsite to water, adding ammonium carbonate to prepare a slurry, soaking the organic foam template in the slurry, drying and sintering to obtain the porous ceramsite; The added mass of the ammonium carbonate is 15% to 25% of the mass of the porous ceramsite; The immersion temperature is 80-100° C., and the immersion time is 10-15 hours.