The Synthesis Of Dehydroacetic Acid Catalyzed By Solid Base

Dehydroacetic acid (DHA) as a white or light yellow crystalline powder, is an important chemical raw materials, intermediates and toughening agents, is also a broad spectrum, low toxicity and efficient anti-corrosion, mildew. China for DHA synthesis of a late start, still a large gap compared with developed countries can not meet the needs of domestic enterprises. Preparation of ethyl acetoacetate dehydroacetic acid because of the production process is simple, mild operating conditions, good safety and environmental protection, domestic and foreign enterprises favored, but the main drawback of the method is the low production yield, and the type of catalyst yield a significant impact. Therefore, the study, preparation of solid base catalyst, and is used catalytic ethyl acetoacetate synthesis of dehydroacetic acid has a very important project value and practical significance.NaX zeolite as a carrier, as the precursor to the three kinds of NaF, NaHCO3and Na2CO3alkaline substances, using prepared by impregnation of solid base catalyst NaHCO3/NaX, Na2CO3/NaX, NaF/of NaX, NaHCO3/Na2CO3/NaX and NaF/NaHCO3/Na2CO3/NaX five catalysts. The effects of loading, calcination temperature and calcination time on the solid base catalyst preparation conditions on the yield of dehydroacetic acid. The results show that the optimal solid base catalyst of NaF/of NaX, the best preparation conditions for20%of the load, the calcination temperature of600℃, calcination time7h. Determination of the alkali content of the solid alkali and alkali strength, and solid alkali were characterized.NaF/of NaX solid alkali as the catalyst, and ethyl acetoacetate as the optimum conditions of synthesis of dehydroacetic acid as a catalyst amount of0.02%, reaction temperature210℃, reaction time7h. Dehydroacetic acid production rate of up to81.0%under the best conditions. The product structure was characterized by melting point and infrared analysis and confirmation.