Synthetic method for continuous saponification and decarboxylation of 4-methyl-5-ethoxyoxazole

A technology of ethoxyoxazole and ethyl ethoxyoxazole, applied in the field of compound synthesis, can solve the problems of low yield of 4-methyl-5-ethoxyoxazole, long reaction time and the like, and achieves Avoid prolonged contact, improve reaction yield and reduce energy consumption

Active Publication Date: 2020-11-10
XIAMEN KINGDOMWAY VI TAMIN INC +1
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Problems solved by technology

[0007] The purpose of the present invention is to provide a method that can significantly increase the yield and shorten the reaction time in order to overcome the low yield and long reaction time defects when adopting the existing method to synthesize 4-methyl-5-ethoxy oxazole. Time continuous saponification decarboxylation method for synthesizing 4-methyl-5-ethoxy oxazole

Method used

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  • Synthetic method for continuous saponification and decarboxylation of 4-methyl-5-ethoxyoxazole

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preparation example Construction

[0032] The synthetic method of the continuous saponification decarboxylation of 4-methyl-5-ethoxy oxazole provided by the invention comprises:

[0033] S1. The organic solution containing ethyl 4-methyl-5-ethoxyoxazole acid is premixed with alkali and then continuously pumped into the tubular reactor I for saponification reaction to obtain a saponification solution;

[0034] S2. The saponification liquid is premixed with acid and alcohol and then continuously pumped into the tubular reactor II for decarboxylation reaction. The obtained decarboxylation liquid is discharged from the outlet of the tubular reactor II to obtain 4-methyl-5- Ethoxyxazole.

[0035] The present invention has no particular limitation on the specific types of tubular reactor I and tubular reactor II, which can be various existing tubular reactors that can realize continuous synthesis and reduce back-mixing of reactants. The length-to-diameter ratio of the two Preferably, each independently is (50-200):1...

Embodiment 1

[0046] S1, respectively configure 1mol / L 4-methyl-5-ethoxy oxazole ethyl ester toluene solution and 20% w / w sodium hydroxide aqueous solution, these two materials are 1 according to unit time volume ratio: The ratio of 0.25 is fully mixed with a mixer and preheated to 50°C, then sent to the tubular reactor I (straight tubular reactor) for reaction, the temperature of the reactor is controlled at 60°C, and the residence time is 5 minutes to obtain a saponified liquid ;

[0047] S2. Fully mix the saponification solution with concentrated hydrochloric acid (concentration is 36% to 38%, the same below) and ethanol according to the volume ratio of 1:0.12:0.25 per unit time and preheat to 60°C, then send it into the tube Type reactor II (straight tube reactor) reaction, control the temperature of the reactor at 65°C, and the residence time is 10 minutes, the decarboxylation liquid is discharged from the outlet of the tube reactor II, separate layers, the water layer is extracted onc...

Embodiment 2

[0049] Synthesize 4-methyl-5-ethoxy oxazole according to the method of Example 1, the difference is that the organic solvent for dissolving 4-methyl-5-ethoxy oxazole ethyl ester is replaced by chloroform, The preheating temperature of tubular reactor II was changed to 50° C., the decarboxylation reaction temperature was changed to 55° C., and the decarboxylation residence time was changed to 20 minutes. The remainder was the same as in Example 1 to obtain 4-methyl-5-ethoxy oxazole, Its content is 99.10%, and the yield is 97.83%.

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Abstract

The invention belongs to the field of compound synthesis, and discloses a synthetic method for continuous saponification and decarboxylation of 4-methyl -5ethoxy oxazole, which comprises the followingsteps: premixing an organic solution containing 4-methyl- 5-ethoxy oxazole acid ethyl ester with alkali, and continuously pumping the mixture into a tubular reactor I for saponification reaction; premixing the obtained saponification liquid with acid and alcohol, continuously pumping the mixture into a tubular reactor II for decarboxylation reaction, discharging the obtained decarboxylation liquid from an outlet of the tubular reactor II, and performing post-treatment to obtain the 4-methyl- 5-ethoxy oxazole. The tubular reactor is adopted for continuous saponification and decarboxylation reaction, so that the reaction time can be remarkably shortened, the reaction yield is increased, the water vapor stripping step is reduced, the saponified reaction liquid does not need to be subjected to operations such as layered extraction, the reaction process flow is shortened, and the energy consumption is reduced.

Description

technical field [0001] The invention belongs to the field of compound synthesis, and in particular relates to a synthesis method for continuous saponification and decarboxylation of 4-methyl-5-ethoxy oxazole. Background technique [0002] 4-Methyl-5-ethoxyoxazole (II) is an intermediate of vitamin B6, which is generally obtained by saponification and decarboxylation of 4-methyl-5-ethoxyoxazole ethyl ester (I). The specific chemical The equation looks like this: [0003] [0004] The saponification and decarboxylation of traditional 4-methyl-5-ethoxy oxazole-acid ethyl ester adopt batch process, and the specific process is as follows: in the organic solution of 4-methyl-5-ethoxy oxazole-acid ethyl Add sodium hydroxide aqueous solution, heat up to carry out saponification reaction, after the reaction is completed, let stand to separate layers, add hydrochloric acid to the water layer until the pH value is 1.5, and then heat to carry out decarboxylation reaction, and then t...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D263/42
CPCC07D263/42
Inventor 赵家宇苏珍莹詹欣马瑞达林兴
Owner XIAMEN KINGDOMWAY VI TAMIN INC
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