Ethyl maltol synthetic method

A technology of ethyl maltol and a synthesis method, applied in the field of chemistry, can solve problems such as environmental pollution, serious environmental pollution, consumption of sodium hydroxide, etc., and achieve the effects of reducing production costs and reducing environmental pollution

Inactive Publication Date: 2009-11-25
CHUZHOU UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] (1) The yield of ethyl maltol is low (about 30%)
[0009] (2) Since the chlorination rearrangement reaction needs to be carried out at a lower temperature, and the hydrolysis reaction needs to be carried out at a higher temperature, the same reactor operates under a larger temperature difference, the energy utilization is unreasonable, and the production cost of the target product too high
[0010] (3) The sodium chloride content in the discharged process wastewater is very high, causing serious environmenta

Method used

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  • Ethyl maltol synthetic method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0032] (1) Preparation of chlorination rearrangement reaction mixture:

[0033] Add 600mL of methanol aqueous solution (the mass fraction of methanol is 60%) into a 1000mL four-neck flask equipped with a stirrer, thermometer, dropping funnel and ventilation tube, cool to -25°C, and add α- A methanol solution of furan propanol (96mL of α-furan propanol with a density of 1.05g / mL and a content of 95.3% mixed with 104mL of methanol), at the same time, chlorine gas was introduced into the bottle at a certain ratio, and the reaction temperature was always maintained at -10~ -12°C. After the methanol solution of α-furan propanol is added dropwise, continue to pass chlorine gas for about 15 minutes until the reaction temperature drops significantly, stop the chlorine gas flow, and continue the reaction for 15 minutes to obtain a hydrolysis mixture containing the product ethyl maltol, with a volume of about 800 mL.

[0034] (2) Hydrolysis of chlorination rearrangement reaction mixtur...

Embodiment 2

[0044] (1) Preparation of chlorination rearrangement reaction mixture: same as Example 1.

[0045] (2) Hydrolysis of chlorination rearrangement reaction mixture:

[0046] Take 100mL of the chlorination rearrangement reaction mixture each time, and add them to five 125mL stainless steel (with polytetrafluoroethylene lining) hydrolysis reaction kettles respectively, and put the reaction kettles into 95°C and 105°C respectively. , 115°C, 125°C, 135°C, 140°C electric blast drying oven, under the hydrolysis pressure of 1.9, 2.6, 3.5, 4.7, 6.1, 6.8MPa, the hydrolysis reaction time is 3.0h, take out the reaction kettle Spray with tap water and be cooled to room temperature (need about 1h), separate the by-product methyl chloride gas that generates in the hydrolysis reaction, obtain the hydrolysis mixed solution that contains product ethyl maltol and measure the volume of hydrolyzate in each reactor ( The volume is 81-92mL).

[0047] Comparative example: with embodiment 1.

[0048]...

Embodiment 3

[0051] (1) Preparation of chlorination rearrangement reaction mixture:

[0052] Add 600 mL of aqueous methanol solutions with mass fractions of 50%, 60%, 70%, 80%, and 90% of methanol in a 1000 mL four-necked bottle equipped with a stirrer, thermometer, dropping funnel, and vent tube, and cool to - At 25°C, add a methanol solution of α-furan propanol drop by drop from the dropping funnel (96 mL of α-furan propanol with a density of 1.05 g / mL and a content of 95.3% is mixed with 104 mL of methanol), and at the same time, start to add a certain proportion to the bottle Chlorine gas is passed through the medium, and the reaction temperature is always maintained at -10 to -12°C. After the methanol solution of α-furan propanol was added dropwise, the chlorine gas flow was continued for about 15 minutes until the reaction temperature dropped significantly, the chlorine gas flow was stopped, and the reaction was continued for 15 minutes to obtain a hydrolysis mixture containing the p...

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Abstract

The invention relates to an ethyl maltol synthetic method, which includes an alpha-furans propanol chlorination rearrangement reaction and a hydrolysis reaction to the product of the alpha-furans chlorination rearrangement reaction. Wherein, the hydrolysis reaction comprises: hydrolyzing the mixture obtained in the chlorination rearrangement reaction under the temperature of 95-140 degrees centigrade and the pressure of 1.9-8.5Mpa for 1.5-5.5 hours; cooling to below 100 degrees centigrade; separating out the by-product: chloromethanes gas; and obtaining the hydrolysis mixed liquor containing the product: ethyl maltol. The invention can achieves the synthesized ethyl maltol yield of 60% which is improved by 4-6% compared with conventional methods; enables the hydrogen chloride generated in the reaction process to react with solvent methanol to generate a large amount of recyclable by-product: chloromethanes; reduces the hydrochloric acid concentration in the hydrolysate by 75-80%; reduces the sodium hydroxide used amount in the subsequent ethyl maltol separating and refining process; and reduces the sodium chloride content in the technique waste water; thereby, reduces environmental pollution and production cost.

Description

technical field [0001] The invention relates to the field of chemistry, in particular to a method for synthesizing ethyl maltol with α-furan propanol. Background technique [0002] The chemical reaction equation for the synthesis of ethyl maltol from α-furan propanol and chlorine is as follows: [0003] [0004] In the formula, the first and second steps are called α-furan propanol chlorination rearrangement reaction, referred to as chlorination rearrangement reaction; the third step is called α-furan propanol chlorination rearrangement reaction product hydrolysis reaction, referred to as for the hydrolysis reaction. The existing synthetic methods are mainly one-pot method and two-pot method: [0005] 1. One pot method [0006] Add methanol aqueous solution (volume ratio 2:3) into a four-neck flask equipped with a stirrer, thermometer, dropping funnel and vent tube, cool to below -5°C, and add α-furan propanol dropwise with a dropping funnel Methanol mixture. Simulta...

Claims

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Application Information

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IPC IPC(8): C07D309/40
Inventor 薛连海葛秀涛吴霖生李永红
Owner CHUZHOU UNIV
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