Method for synthesizing pentanone-2 through Bayer-Vlieger oxidation reaction

Abstract

The invention relates to a method for synthesizing pentanone-2 through a Bayer-Vlieger oxidation reaction. The pentanone-2 is prepared by using propionaldehyde as a raw material, performing alkaline condensation and the Bayer-Vlieger oxidation reaction on the propionaldehyde, and finally performing hydrolysis under an acid condition. The method comprises the following process steps of: (1) condensing the propionaldehyde at the temperature of 30 to 40 DEG C under the action of solution of NaOH to obtain 2-methyl-2-pentenal; (2) preparing buffer solution of acetic acid and sodium acetate from the product obtained in the step (1) by taking the acetic acid as solvent in the presence of the sodium acetate, controlling the pH of a reaction system to be between 3.7 and 6, and at the temperature of 10 to 30 DEG C, using peroxyacetic acid to perform B-V oxidation so as to obtain formic acid-2-amylene-2-alcohol ester; and (3) using H2SO4 aqueous solution to reflux and hydrolyze the product obtained in the step (2) under an acidic condition to prepare the pentanone-2. The quality of the pentanone-2 meets the requirements of preparing a flavoring essence and an essence for household and personal care chemicals. The method has the advantages of readily available raw materials, simple process, high yield, single product component, easy refining, high product quality, low cost and suitability for industrial production.

Description

technical field The invention belongs to the technical field of spice organic synthesis, and relates to a method for synthesizing pentanone-2, in particular to a Bayer-Villiger reaction (Baeyer-villiger, B-V reaction) for synthesizing pentanone-2 using a peroxygen reagent as an oxidant. 2 new methods. Background technique Pentanone-2 is an important aroma raw material, which has a fresh and elegant ether aroma, sweet aroma, fermented cheese and banana fruit-like aroma. It can be widely used in cheddar cheese, milk, banana, jackfruit and other fruity food flavors, and can also be used in various fruity daily chemical flavors. The preparation of pentanone-2 is reported in the literature by dry distillation of calcium acetate and calcium butyrate (Annalen, 108, 124, 1858), or by oxidation of sodium n-hexanoate or n-hexanoic acid with hydrogen peroxide, but these The composition of the finished product prepared by the method is complex, and the product is difficult to purify....

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Problems solved by technology

Ketones can smoothly generate esters or lactones when B-V reactions occur. When aldehydes undergo B-V reactions, due to the easy oxidation of aldehyde groups, the main product is that the aldehyde group is oxidized to carboxylic acid, which is oxidized to form formate. very low rate

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