Study on Synthesis of Calone
|Keywords||Watermelon ketone Dieckmann condensation Hydrolysis decarboxylation Sodium sand|
Watermelon ketone as a flavors and fragrances , is now widely used in cosmetics, food , and therefore its study of the synthesis process is of great significance . Used herein, 4 - methyl catechol diacetate ester as raw materials, two-step reaction synthesis by Dieckmann condensation and hydrolysis decarboxylation one watermelon , and optimize their respective process conditions , various factors affect Dieckmann condensation and hydrolysis decarboxylation reaction studied. This study can be roughly divided into the following two parts: the investigated Dieckmann condensation reaction catalyst type , amount of catalyst, the amount of sodium sand methanol , solvents , and other single factor changes the reaction effect and by orthogonal experiment the method of determining the influence of various factors on the reaction yield significant order , descending , respectively: a catalyst , a catalyst with the raw material 4 - methyl catechol diacetate methyl ester in molar ratio, reaction solvent, reaction temperature . Optimum conditions: Dieckmann condensation reaction of sand with sodium as the catalyst; amount of sodium sand with the raw material molar ratio is 2:1 ; sodium sand in the amount of methanol with the raw material molar ratio is 0.75 ; toluene as solvent, the solvent is used in an amount of 70mL ; reaction temperature 60 ℃; reaction time was 4 hours , Dieckmann, a condensation reaction product of 7 - methyl-3 ,4 - dihydro -2H - 2- methoxy - carbonyl - 1 ,5 - benzo dioxa the Zhuo -3 - ketone closing rate up to 68.77% . Investigated the hydrolysis decarboxylation during the reaction , type of catalyst , amount of catalyst , temperature and other factors change the impact of the reaction effect , determine the optimum conditions of the hydrolysis decarboxylation reaction : 6 mol / L hydrochloric acid and acetic acid as catalyst ; catalyst with reactants a molar ratio of 5:1; reaction time of 8 hours ; reaction temperature 80 ° C , hydrolysis decarboxylation reaction yield of 83.35% . Dieckmann condensation and hydrolysis decarboxylation two-step reaction , one watermelon final yield of 57.32% . Ultimately Dieckmann condensation and hydrolysis decarboxylation reaction products IR, GC-MS , NMR analysis identified the structure of matter .