A Study On The Synthesis And Purification Process Of Calone1951

The Calone1951is a kind of synthesis fragrance, and used in different area suchas in food and cosmetics, which could give people the feeling of sweet, so its maketvalue has improved gradually. The synthesis of Calone1951is made from4-methylcatechol and methyl bromoacetate via the first step a Williamson condensation reaction,to synthesis the4-methylcatechol dimethylacetate, then go on with Dickmancondensation reaction, hydrolysis–decarboxylation reaction to get the finalproduct.However, the yield of4-methylcatechol dimethylacetate through this way isonly78%, and the yield of Calone1951is only56%.It was found that the addition of a suitable amount of KI as catalysts cansignificantly increase the product yield due to the generation of methyl iodoacetate viathe reaction of KI with methyl bromoacetate. In order to find out the effection of KI as acatalyst to the reation mechanism, designed a group of orthogonal experiments withinteraction, and obtained the optimum operating conditions: KI:C₇H₈O₂（mol:mol）=0.75:1; C₃H₅BrO₂:C₇H₈O₂（mol: mol）=3.5:1; K₂CO₃:C₇H₈O₂（mol: mol）=4:1;reaction time=6h; reaction temperature=80℃, and also abtained the order of the influentfactors: KI＞the interaction between KI and methyl bromoacetate＞reactiontemperature＞K₂CO₃＞reaction time＞methyl bromoacetate. The yield of4-Methylcatechol dimethylacetate can reach94.7%and the corresponding yield ofCalone1951was up to67.6%.This observably improved the yield.This thesis also research the aftercure of the first step, according to differentboiling points of the products, took use of reduced pressure disstillation to replace theextraction and disstillation, finally got the product with yield96%, and used HPLC tomake sure its characterization. In addition, this new technology recycle the raw materialmethyl bromoacetate, with obviously reduce the cost.At last, this thesis disscussed about the purify process of slica columnchromatography. The most suitable solvent is mixture with cyclohexane and ethanol,and their valume ratio is20:1, the structure and purity of the product were firstlyanalyzed by using melting point measurement, IR, NMR and HPLC methods. The yieldthrough slica column chromatography is23%.