Alpha-furan ring-containing pentaerythritol hetero diacetal (ketone) and preparation method thereof

Abstract

The invention discloses alpha-furan ring-containing pentaerythritol hetero diacetal (ketone) and a preparation method thereof. The structure of the alpha-furan ring-containing pentaerythritol hetero diacetal (ketone) is as shown in a formula (5); the alpha-furan ring-containing pentaerythritol hetero diacetal (ketone) is prepared by the following two steps of firstly, by taking homemade sulfonated carbon as a catalyst, and taking cyclohexane as a water-carrying agent, adding DMF (Dimethyl Formamide) into a mixture, and reacting furaldehyde with pentaerythritol to prepare pentaerythritol monoacetal; secondly, by taking the homemade sulfonated carbon as the catalyst, and taking the cyclohexane as the water-carrying agent, adding the DMF, reacting the pentaerythritol monoacetal with aldehyde (or ketone) to prepare the compound as shown in the formula (5). After an improvement method is used, reaction time can be shortened from 6 hours to 2 to 3 hours, and the yield of the pentaerythritol monoacetal (ketone) is improved from 40 to 50 percent to over 70 percent, and the yield of the pentaerythritol hetero diacetal (ketone) is improved from 30 to 40 percent to 50 to 70 percent; after the prepared furaldehyde, pentaerythritol monoacetal and hetero diacetal products are placed at dark places and stored for over one year, no blackening phenomenon is caused.

Description

technical field [0001] The invention belongs to the field of chemical synthesis, and relates to a pentaerythritol heterodiacetal (ketone) containing an α-furan ring and a preparation method thereof. Background technique [0002] Furfural, also known as 2-furaldehyde, its scientific name is α-furaldehyde, is a derivative in which the hydrogen atom at the 2-position of furan is replaced by an aldehyde group. It was originally made from rice bran heated with dilute acid, so it is called furfural. Furfural is formed by hydrolysis of pentosan under the action of acid to generate pentose, and then dehydration and cyclization of pentose. The main raw materials for production are agricultural and sideline products such as corncobs. There are many synthetic methods. Furfural is the most important derivative of the furan ring system. It is chemically active and can produce many derivatives through oxidation, condensation and other reactions. , synthetic fibers and other chemical r...

AI Technical Summary

Problems solved by technology

But when preparing the monoacetal and heterodiacetal of furfural and pentaerythritol with the above method, there are following problems: (1) DMF is a strong polar solvent, which is miscible with water, and there is water to generate in the condensation process of pentaerythritol and aldehyde (ketone) , when using DMF as a solvent, the water generated in the reaction cannot be removed in time; (2) when p-toluenesulfonic acid is used as a catalyst, in the post-treatment process, it must be washed with lye and then washed with water, while pentaerythritol acetal (ketone) is easily hydrolyzed in aqueous solution to generate raw materials pentaerythritol and aldehyde (ketone), resulting in a reduction in yield; (3) the reaction rate of this reaction is slow and the reaction time is long (usually the reaction time is more than 6-8 hours); (4) The monoacetal and heterodiacetal (ketone) synthesized by furfural and pentaerythritol are easy to oxidize and turn black, especially in hot weather, which affects product quality and limits its use. It must be avoided by using nitrogen blanketing. In this case, the furfural and pentaerythritol monoacetal and heterodiacetal products prepared by this method have not been blackened after being stored in a dark place for more than one year.

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