The Synthesis Of Ortho-vanillin By Ortho-formylation Of Guaiacol

As an important intermediate of organic synthesis and flavoring additive,ortho vanillin is widely used in pharmaceutical production,organic synthesis and cosmetic manufacture.At present,the annual production of ortho vanillin in China is only about 10,000 tons.At present,ortho vanillin is only obtained by separation and purification as a by-product of vanillin production.Due to the difficulty in the separation of ortho vanillin and its isomers,the final purity of ortho vanillin products cannot be guaranteed.Northeast China pharmaceutical factory mainly USES ortho vanillin as the raw material for the production of hydrochloride berberine.Based on the quality and yield of the above ortho vanillin,the large-scale production of hydrochloride berberine is limited,and there are many impurities in the products.Therefore,it is very important to develop an economical,green,efficient and selective method for the synthesis of ortho vanillin.This paper introduces a with catechol as raw material after methylation first formly combined into ortho vanillin method,and research on the method is as follows: first,through analysis of guaiacol synthesis method after comparison with catechol as raw materials,dimethyl sulfate as a methylation reagent preparation of guaiacol,involved in the reaction conditions and the optimized,results the dosage of the neighbors benzodiazepines 0.1 mol?11.1g?,dimethyl sulfate methylation reagent amount to 0.12mol?11.4g?,n_pyrocatechol:n_{dimethyl sulfate}= 1:1.2,neighbors xylene as solvent,the am-ount of solvent is 80 ml,cocatalyst choose tetrabutyl ammonium bromide,dosage of 1.0 g,regulating system with Na OH solution p H is 10,the reaction time is 80 minutes.Finally,the product was tested by infrared spectroscopy and gas chromatography-mass spectrometry.The reaction mechanism of the reaction was also investigated.Secondly,choose metal ion catalytic method of guaiacol and paraformaldehyde ortho vanillin was synthesized and the reaction of the reactants involved in dosage is optimized,the result is in300 ml of acetonitrile solvent,dosage of guaiacol was 0.1mol?12.4g?,the amount of anhydrous magnesium chloride 0.1mol?9.52g?,0.1mol,dosage of triethylamine?10.11g?,dosage of paraformaldehyde 0.3 mol?9g?,n_guaiacol: n_{anhydrous magnesium chloride}: n_{triethylamine}:n_{paraformaldehyde}=1:1:1:3.Finally,the products were tested by IR,GC-MS and HPLC.In addition,the Dmol3 module in Material Studio 2017 software was used to optimize the reactant structure and calculate the reaction energy barrier using density functional theory,and the reaction mechanism of the reaction was determined.In this study,the cheap and readily available material catechol was used as raw material,the efficient methylation method and the ortho-selective formylation method were selected,which had positive significance for the realization of the chemical synthesis of ortho-vanillin,the reduction of production cost and the shortening of the process.