Synthesis method of pseudoionone

Abstract

The invention discloses a synthesis method of pseudoionone. The synthesis method comprises the following steps: carrying out condensation reaction on acetone and geranialdehyde under the conditions that the temperature is 230-300 DEG C and the pressure is 5-25 MPa; separating to obtain the pseudoionone after completely reacting. By adopting the synthesis method, no basic catalyst is introduced; purification of the product is facilitated; the synthesis method has the advantages of being high in product purity (greater than or equal to 98.5%), high in yield (up to 93.8%), few in by-products (1.0-8%), simple in processing steps, green, energy-saving, environment-friendly and the like; the dosage of acetone for reaction is greatly reduced.

Description

technical field

[0001] The invention relates to a synthetic method of a chemical intermediate, in particular to a synthetic method of a pseudoionone. Background technique

[0002] In recent years, supercritical fluid technology has been widely used in the chemical industry. It has been found that chemical reactions carried out in supercritical fluid can increase the reaction rate and change the reaction process while maintaining or improving the selectivity. Pseudo-ionone is an important intermediate in the synthesis of flavors and fragrances such as ionone, vitamins A, E and β-carotene. It is described in detail in US Patent US5453546 and German Patent DE19619557. It is used in flavors and fragrances, medicine, food additives and synthetic chemistry. It is also widely used. There are two main synthetic process routes of pseudoionones: the first synthetic process route is also the most commonly used industrial route, which is to generate pseudoionones by Aldol condensation ...

Examples

preparation example Construction

[0030] by such as figure 1 As can be seen from the shown device diagram, the device diagram used for the synthetic method of pseudoionone comprises: high-pressure reactor 7, citral feed pipeline and acetone feed pipeline connected with the inlet of high-pressure reactor 7 respectively and The evaporator 8 communicated with the outlet of the high-pressure reactor and the product collection device (omitted in the figure) communicated with the outlet of the evaporator 8 .

[0031] The citral feed pipeline includes a citral feed pump 2, a citral booster pump 5 and a citral flow control pump 6 connected in sequence; the acetone feed pipeline includes acetone feed pump 1 connected in sequence , Acetone booster pump 3 and acetone flow control pump 4.

[0032] Using the above-mentioned device, the best reaction condition is acetone: citral = 0.5-2.0 (mass ratio), the best is 1.0-2.0 times (mass ratio), pressurize acetone and citral, and then measure them into the high-pressure reacto...

Embodiment 1

[0035] according to figure 1In the described device, the feed rate of acetone is 100g / min, and the feed rate of citral is 100g / min. After preheating, the temperature is raised to 230°C, and the pressure is increased to 21MPa to enter a reactor with a pressure of 21MPa and a temperature of 230°C. The control residence time was 10 minutes. On-line GC analysis showed that the conversion rate of citral was 75.6%. The excess acetone and the product pseudo-ionone were separated from the reaction liquid through the evaporator, and the output was intercepted for half an hour. After treatment, 2770.24g of high-purity product was obtained. After GC analysis, the retention time was exactly the same as that of the standard product. The GC purity was above 94%, and the yield was 73.1%.

Embodiment 2

[0037] according to figure 1 In the described device, the feed rate of acetone is 100g / min, and the feed rate of citral is 100g / min. After preheating, the temperature is raised to 240°C, pressurized to 21MPa and entered into a reactor with a pressure of 21MPa and a temperature of 240°C. The control residence time was 10 minutes. On-line GC analysis showed that the conversion rate of citral was 97.2%. The excess acetone and product pseudo-ionone were separated from the reaction liquid through the evaporator, and the output was intercepted for half an hour. After treatment, 3505.44g of high-purity product was obtained. After GC analysis, the retention time was exactly the same as that of the standard product. The GC purity was above 94%, and the yield was 92.5%.

technical field

[0001] The invention relates to a synthetic method of a chemical intermediate, in particular to a synthetic method of a pseudoionone. Background technique

[0002] In recent years, supercritical fluid technology has been widely used in the chemical industry. It has been found that chemical reactions carried out in supercritical fluid can increase the reaction rate and change the reaction process while maintaining or improving the selectivity. Pseudo-ionone is an important intermediate in the synthesis of flavors and fragrances such as ionone, vitamins A, E and β-carotene. It is described in detail in US Patent US5453546 and German Patent DE19619557. It is used in flavors and fragrances, medicine, food additives and synthetic chemistry. It is also widely used. There are two main synthetic process routes of pseudoionones: the first synthetic process route is also the most commonly used industrial route, which is to generate pseudoionones by Aldol condensation ...

Examples

preparation example Construction

[0030] by such as figure 1 As can be seen from the shown device diagram, the device diagram used for the synthetic method of pseudoionone comprises: high-pressure reactor 7, citral feed pipeline and acetone feed pipeline connected with the inlet of high-pressure reactor 7 respectively and The evaporator 8 communicated with the outlet of the high-pressure reactor and the product collection device (omitted in the figure) communicated with the outlet of the evaporator 8 .

[0031] The citral feed pipeline includes a citral feed pump 2, a citral booster pump 5 and a citral flow control pump 6 connected in sequence; the acetone feed pipeline includes acetone feed pump 1 connected in sequence , Acetone booster pump 3 and acetone flow control pump 4.

[0032] Using the above-mentioned device, the best reaction condition is acetone: citral = 0.5-2.0 (mass ratio), the best is 1.0-2.0 times (mass ratio), pressurize acetone and citral, and then measure them into the high-pressure reacto...

Embodiment 1

[0035] according to figure 1In the described device, the feed rate of acetone is 100g / min, and the feed rate of citral is 100g / min. After preheating, the temperature is raised to 230°C, and the pressure is increased to 21MPa to enter a reactor with a pressure of 21MPa and a temperature of 230°C. The control residence time was 10 minutes. On-line GC analysis showed that the conversion rate of citral was 75.6%. The excess acetone and the product pseudo-ionone were separated from the reaction liquid through the evaporator, and the output was intercepted for half an hour. After treatment, 2770.24g of high-purity product was obtained. After GC analysis, the retention time was exactly the same as that of the standard product. The GC purity was above 94%, and the yield was 73.1%.

Embodiment 2

[0037] according to figure 1 In the described device, the feed rate of acetone is 100g / min, and the feed rate of citral is 100g / min. After preheating, the temperature is raised to 240°C, pressurized to 21MPa and entered into a reactor with a pressure of 21MPa and a temperature of 240°C. The control residence time was 10 minutes. On-line GC analysis showed that the conversion rate of citral was 97.2%. The excess acetone and product pseudo-ionone were separated from the reaction liquid through the evaporator, and the output was intercepted for half an hour. After treatment, 3505.44g of high-purity product was obtained. After GC analysis, the retention time was exactly the same as that of the standard product. The GC purity was above 94%, and the yield was 92.5%.

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