Preparation of o-nitrobenzaldehyde by biomimetic catalysis oxidation of o-nitrotoluene with oxygen

Abstract

The invention relates to a process for preparing aromatic aldehydes, in particular a process for preparing p-nitrobenzaldehyde through bionic catalytic oxidation of p-nitrotoluene, wherein metallic phthalocyanine, single nuclear metalloporphyrin or mu-oxy-double nuclear metalloporphyrin having the similar structure as the biological enzymes are selected as the catalyst for the disclosed process, whose dose is 0.1-1.0% weight of p-nitrotoluene, and methyl alcohol is used as solvent, 0.5-3.0 MPa oxygen is let into 0.7-2.8 mol / L strong alkaline methyl alcohol solution, controlling the reaction temperature to be 20-65 deg. C, the reaction time being 6-48 hrs.

Description

technical field

[0001] The invention relates to a method for preparing aromatic aldehydes, in particular to a method for preparing p-nitrobenzaldehyde by biomimetic catalyzing oxygen oxidation of p-nitrotoluene. Background technique

[0002] At present, the preparation methods of p-nitrobenzaldehyde are mainly divided into two types: one is the method of oxidative hydrolysis with p-nitrotoluene and acetic anhydride as raw materials; the other is to use mixed acid for nitration and hydrolysis, and use copper-based complexes as catalysts method of catalytic oxidation. When the former uses metal compounds to oxidize p-nitrotoluene, the utilization rate of raw materials is low, and the environment is seriously polluted. The latter uses benzyl chloride as a raw material and uses a copper-based complex as a catalyst, and the by-product is o-nitrobenzaldehyde. This method has serious environmental pollution and is difficult to separate from the by-product. Therefore, whether the ...

Examples

Embodiment 1

[0023] Weigh 3mg of cobalt phthalocyanine (i.e. R=H in general formula (I), M 1 =Co), 2.8g of p-nitrotoluene and 2.8g of NaOH were charged into a 200ml autoclave, 50ml of methanol was added, oxygen at a pressure of 1.6MPa was introduced, and the reaction was carried out in a water bath at a temperature of 45°C for 12h. The mixed solution after the reaction was first removed the catalyst through suction filtration, then added 50ml of distilled water, added dilute hydrochloric acid to neutralize, filtered, after purification, analyzed and detected by high pressure liquid chromatography, the yield of p-nitrobenzaldehyde was 18.2%. The purity of the final product was 99.0%.

Embodiment 2

[0025] Weigh 10mg of iron phthalocyanine (i.e. R=H in general formula (I), M 1 =Fe), 2.8g of p-nitrotoluene, 3.5g of sodium hydroxide were put into a 200ml autoclave, 50ml of methanol was added, the oxygen pressure was 0.5MPa, the temperature was controlled at 65°C in a water bath, and the reaction was carried out for 6h. The processing steps are the same as in Example 1, and the resulting product is analyzed and detected by high-pressure liquid chromatography. The yield of p-nitrobenzaldehyde is 23.6%, and the purified product has a purity of 98.5%.

Embodiment 3

[0027] Weigh 14mg of copper phthalocyanine (i.e. R=H in general formula (I), M 1 =Cu), 2.8g p-nitrotoluene, 1.4g sodium hydroxide were put into a 200ml autoclave, 50ml methanol was added, the oxygen pressure was 3.0MPa, the temperature was controlled at 20°C in a water bath, and the reaction was carried out for 48h. The processing steps are the same as in Example 1, and the resulting product is detected by high-pressure liquid chromatography, and the yield of p-nitrobenzaldehyde is 16.7%, and the purified product has a purity of 99.5%.

technical field

[0001] The invention relates to a method for preparing aromatic aldehydes, in particular to a method for preparing p-nitrobenzaldehyde by biomimetic catalyzing oxygen oxidation of p-nitrotoluene. Background technique

[0002] At present, the preparation methods of p-nitrobenzaldehyde are mainly divided into two types: one is the method of oxidative hydrolysis with p-nitrotoluene and acetic anhydride as raw materials; the other is to use mixed acid for nitration and hydrolysis, and use copper-based complexes as catalysts method of catalytic oxidation. When the former uses metal compounds to oxidize p-nitrotoluene, the utilization rate of raw materials is low, and the environment is seriously polluted. The latter uses benzyl chloride as a raw material and uses a copper-based complex as a catalyst, and the by-product is o-nitrobenzaldehyde. This method has serious environmental pollution and is difficult to separate from the by-product. Therefore, whether the ...

Examples

Embodiment 1

[0023] Weigh 3mg of cobalt phthalocyanine (i.e. R=H in general formula (I), M 1 =Co), 2.8g of p-nitrotoluene and 2.8g of NaOH were charged into a 200ml autoclave, 50ml of methanol was added, oxygen at a pressure of 1.6MPa was introduced, and the reaction was carried out in a water bath at a temperature of 45°C for 12h. The mixed solution after the reaction was first removed the catalyst through suction filtration, then added 50ml of distilled water, added dilute hydrochloric acid to neutralize, filtered, after purification, analyzed and detected by high pressure liquid chromatography, the yield of p-nitrobenzaldehyde was 18.2%. The purity of the final product was 99.0%.

Embodiment 2

[0025] Weigh 10mg of iron phthalocyanine (i.e. R=H in general formula (I), M 1 =Fe), 2.8g of p-nitrotoluene, 3.5g of sodium hydroxide were put into a 200ml autoclave, 50ml of methanol was added, the oxygen pressure was 0.5MPa, the temperature was controlled at 65°C in a water bath, and the reaction was carried out for 6h. The processing steps are the same as in Example 1, and the resulting product is analyzed and detected by high-pressure liquid chromatography. The yield of p-nitrobenzaldehyde is 23.6%, and the purified product has a purity of 98.5%.

Embodiment 3

[0027] Weigh 14mg of copper phthalocyanine (i.e. R=H in general formula (I), M 1 =Cu), 2.8g p-nitrotoluene, 1.4g sodium hydroxide were put into a 200ml autoclave, 50ml methanol was added, the oxygen pressure was 3.0MPa, the temperature was controlled at 20°C in a water bath, and the reaction was carried out for 48h. The processing steps are the same as in Example 1, and the resulting product is detected by high-pressure liquid chromatography, and the yield of p-nitrobenzaldehyde is 16.7%, and the purified product has a purity of 99.5%.

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