Process for preparing piperonal

A piperonal, extraction technology, applied in the field of preparation of piperonal, can solve the problem of quality reduction

Inactive Publication Date: 2003-03-05
UBE IND LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Therefore, there is a problem of coloring piperonal and lowering the quality

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] In a flat-bottomed separable flask with an inner volume of 7 liters, add 500.0 grams (4.09 moles) of 1,2-methylenedioxybenzene and 250 milliliters of 4-methyl-2-pentanone under nitrogen atmosphere, and stir Cool down to -5°C. Next, a mixed solution of 833.4 g (4.44 mol) of 40% by weight glyoxylic acid aqueous solution and 857.8 g (8.4 mol) of 96% by weight sulfuric acid was slowly added dropwise, followed by stirring at -5°C for 21 hours.

[0043] Then, 3000 ml of 4-methyl-2-pentanone was added, followed by maintaining the solution temperature at -10°C to -5°C, while slowly adding 1030.0 g (16.9 mol) of 28% by weight ammonia water dropwise for neutralization. After the neutralization was completed, it was heated to 80° C., and 3,4-methylenedioxymandelic acid was extracted in the 4-methyl-2-pentanone layer (organic solvent layer). At this time, the reaction solution was separated into two layers, an organic solvent layer and an aqueous layer.

[0044] Next, the aqueous...

Embodiment 2

[0047] In a flat-bottomed separable flask with an inner volume of 500 ml, add 50.0 g (409.4 mmol) of 1,2-methylenedioxybenzene and 50 ml of glyoxylic acid under nitrogen atmosphere, and then cool to 0°C under stirring . Next, a mixed solution of 83.4 g (450.6 mmol) of 40% by weight glyoxylic acid aqueous solution and 85.8 g (839.8 mmol) of 96% by weight sulfuric acid was slowly added dropwise, followed by stirring at 5° C. for 21 hours.

[0048] Then, 200 ml of ethyl acetate was added, followed by maintaining the solution temperature at -10° C. to 5° C., and slowly adding 102.0 g (1677 mmol) of 28% by weight ammonia water dropwise for neutralization. After the neutralization was completed, it was heated to 60° C., and 3,4-methylenedioxymandelic acid was extracted in the ethyl acetate layer (organic solvent layer). At this time, the reaction solution was separated into two layers, an organic solvent layer and an aqueous layer.

[0049] Next, the aqueous layer was removed and ...

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PUM

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Abstract

A process for preparing piperonal, characterized by comprising the three successive steps: (A) the addition step of reacting 1,2-methylenedioxybenzene with glyoxylic acid in the presence of a strong acid to form 3,4-methylenedioxymandelic acid, (B) the extraction step of adding an organic solvent to the reaction fluid and then neutralizing the resulting fluid with a base to thereby extract 3,4-methylenedioxymandelic acid into the organic solvent and separate the fluid into an organic solvent layer and an aqueous layer, and (C) the oxidation step of removing the aqueous layer, concentrating the organic solvent layer, adding nitric acid to the concentrate, and then making the 3,4-methylenedioxymandelic acid react with the nitric acid to form piperonal.

Description

technical field [0001] The present invention relates to the preparation method of piperonal, in more detail, is to relate to take 1,2-methylenedioxybenzene as starting material, in the reaction process, intermediate 3,4-methylenedioxymandelic acid is not A method for preparing high-quality piperonal in high yield by taking out crystallization. Background technique [0002] Piperonal is the blending base material of heliotrope spices. In addition to being widely used in general cosmetic spices, it is also a useful compound as a synthetic raw material for pharmaceuticals and agricultural chemicals or as a smoothing agent for metal plating. [0003] As a preparation method for preparing piperonal, a method for preparing piperonal by oxidizing 3,4-methylenedioxymandelic acid with nitric acid is well known (for example, P.S. Raman Current Science, 27, 22 (1958), Perfumer & Flavourist, 14 , 13(1989), EP429316, etc.), and it is known that 3,4-methylenedioxymandelic acid can be pre...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07D317/54
CPCC07D317/54
Inventor 原田胜正白井昌志斯波晃司古谷敏男
Owner UBE IND LTD
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