Method for preparing p-cresol into p-hydroxy benzaldehyde by catalytic oxidation of metalloporphyrin-metal salt composite catalyst

Abstract

The invention relates to a method for preparing p-cresol into p-hydroxy benzaldehyde by the catalytic oxidation of a metalloporphyrin-metal salt composite catalyst. The method comprises the following steps: taking the p-cresol as a raw material, taking methanol or methanol water solution as a solvent, taking a combination of metalloporphyrin and metal salt as a catalyst or taking a combination of any two or three in a formula (1), a formula (II) or a formula (III) as a catalyst or taking a combination of the formula (1) and the formula (I), a combination of the formula (II) and the formula (II) and a combination of the formula (III) and the formula (III) as a catalyst, wherein the concentration of metalloporphyrin is 5-100 ppm, the concentration of the metal salt is 5-200 ppm, and the dosage of sodium hydroxide is 1-2.5 times of the molar dosage of the p-cresol; introducing oxygen of 0.1-1.0 MPa; and reacting for 1-12 hours at a temperature of 50-90 DEG C to obtain the p-hydroxy benzaldehyde. The method has the advantage that while a target product with high yield is obtained, the dosage of the catalyst is extremely less, and the alkali dosage is also remarkably reduced, so that not only can resources be effectively saved, and can the environment pollution be reduced, but also the purpose of reducing energy consumption can be achieved, and further, the effects of energy conservation and emission reduction can be completely realized.

Description

technical field

[0001] The invention relates to a method for preparing aromatic aldehydes, in particular to a method for preparing p-hydroxybenzaldehyde by catalyzing the oxidation of p-cresol with a metalloporphyrin-metal salt composite catalyst. Background technique

[0002] p-Hydroxybenzaldehyde is an important organic synthesis intermediate, widely used in medicine, pesticide, dyestuff and other fields. Although there are many methods for synthesizing p-hydroxybenzaldehyde from p-cresol at present, the biomimetic catalytic oxidation of metalloporphyrins is relatively superior. European patent EP330036A1 (disclosure date: August 30, 1989) discloses a method for preparing p-hydroxybenzaldehyde by biomimetic catalytic oxygen oxidation of p-cresol, which uses metalloporphyrin or metalloporphyrin-metal salt as a catalyst, The problem of environmental pollution caused by the use of a large amount of cobalt chloride catalyst in the traditional method (EP0012939A1, publication ...

Examples

Embodiment 1

[0022] Take 6.4×10 -3 g chloride tetra-(p-methoxyphenyl) cobalt porphyrin (i.e. R in the general formula (II) 21 =R 22 = H, R 23 =OCH 3 , X=Cl,M 2 =Co), 3.2×10 -2 Add 1 g of ferrous acetate, 12.0 g of p-cresol and 12.0 g of sodium hydroxide into a 100 mL autoclave, add 40 mL of methanol, feed oxygen at a pressure of 0.2 MPa, and react in a water bath at a temperature of 65°C for 10 h. After the reaction was completed, the reaction liquid was detected by high performance liquid chromatography, and the conversion rate of p-cresol was 99.2%, the selectivity of p-hydroxybenzaldehyde was 80.0%, and the yield of p-hydroxybenzaldehyde was 79.4%.

Embodiment 2

[0024] Take 8.6×10 -4 g chloride tetra-(p-nitrophenyl)iron porphyrin (i.e. R in the general formula (II) 21 =R 22 = H, R 23 =NO 2 , X=Cl,M 2 =Fe), 3.8×10 -4 Add 1g zinc chloride, 16.0g p-cresol and 8.9g sodium hydroxide into a 100mL autoclave, add 40mL methanol, feed oxygen at a pressure of 0.6MPa, and react in a water bath at a temperature of 70°C for 5h. After the reaction was completed, the reaction solution was detected by high performance liquid chromatography, and the conversion rate of p-cresol was 83.0%, the selectivity of p-hydroxybenzaldehyde was 67.4%, and the yield of p-hydroxybenzaldehyde was 55.9%.

Embodiment 3

[0026] Take 6.4×10 -3 g chloride tetra-(p-methoxyphenyl)iron porphyrin (i.e. R in the general formula (II) 11 =R 12 = H, R 13 =OCH 3 , X=Cl,M 2 =Fe), 1.8×10 -3 Add g cobalt acetate, 16.0 g p-cresol and 14.5 g sodium hydroxide into a 100 mL autoclave, add 40 mL methanol, feed oxygen at a pressure of 0.2 MPa, and react in a water bath at 65°C for 10 h. After the reaction was completed, the reaction liquid was detected by high performance liquid chromatography, and the conversion rate of p-cresol was 99.9%, the selectivity of p-hydroxybenzaldehyde was 87.1%, and the yield of p-hydroxybenzaldehyde was 87.0%.

technical field

[0001] The invention relates to a method for preparing aromatic aldehydes, in particular to a method for preparing p-hydroxybenzaldehyde by catalyzing the oxidation of p-cresol with a metalloporphyrin-metal salt composite catalyst. Background technique

[0002] p-Hydroxybenzaldehyde is an important organic synthesis intermediate, widely used in medicine, pesticide, dyestuff and other fields. Although there are many methods for synthesizing p-hydroxybenzaldehyde from p-cresol at present, the biomimetic catalytic oxidation of metalloporphyrins is relatively superior. European patent EP330036A1 (disclosure date: August 30, 1989) discloses a method for preparing p-hydroxybenzaldehyde by biomimetic catalytic oxygen oxidation of p-cresol, which uses metalloporphyrin or metalloporphyrin-metal salt as a catalyst, The problem of environmental pollution caused by the use of a large amount of cobalt chloride catalyst in the traditional method (EP0012939A1, publication ...

Examples

Embodiment 1

[0022] Take 6.4×10 -3 g chloride tetra-(p-methoxyphenyl) cobalt porphyrin (i.e. R in the general formula (II) 21 =R 22 = H, R 23 =OCH 3 , X=Cl,M 2 =Co), 3.2×10 -2 Add 1 g of ferrous acetate, 12.0 g of p-cresol and 12.0 g of sodium hydroxide into a 100 mL autoclave, add 40 mL of methanol, feed oxygen at a pressure of 0.2 MPa, and react in a water bath at a temperature of 65°C for 10 h. After the reaction was completed, the reaction liquid was detected by high performance liquid chromatography, and the conversion rate of p-cresol was 99.2%, the selectivity of p-hydroxybenzaldehyde was 80.0%, and the yield of p-hydroxybenzaldehyde was 79.4%.

Embodiment 2

[0024] Take 8.6×10 -4 g chloride tetra-(p-nitrophenyl)iron porphyrin (i.e. R in the general formula (II) 21 =R 22 = H, R 23 =NO 2 , X=Cl,M 2 =Fe), 3.8×10 -4 Add 1g zinc chloride, 16.0g p-cresol and 8.9g sodium hydroxide into a 100mL autoclave, add 40mL methanol, feed oxygen at a pressure of 0.6MPa, and react in a water bath at a temperature of 70°C for 5h. After the reaction was completed, the reaction solution was detected by high performance liquid chromatography, and the conversion rate of p-cresol was 83.0%, the selectivity of p-hydroxybenzaldehyde was 67.4%, and the yield of p-hydroxybenzaldehyde was 55.9%.

Embodiment 3

[0026] Take 6.4×10 -3 g chloride tetra-(p-methoxyphenyl)iron porphyrin (i.e. R in the general formula (II) 11 =R 12 = H, R 13 =OCH 3 , X=Cl,M 2 =Fe), 1.8×10 -3 Add g cobalt acetate, 16.0 g p-cresol and 14.5 g sodium hydroxide into a 100 mL autoclave, add 40 mL methanol, feed oxygen at a pressure of 0.2 MPa, and react in a water bath at 65°C for 10 h. After the reaction was completed, the reaction liquid was detected by high performance liquid chromatography, and the conversion rate of p-cresol was 99.9%, the selectivity of p-hydroxybenzaldehyde was 87.1%, and the yield of p-hydroxybenzaldehyde was 87.0%.

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