Preparation, Characterization And Application Of LDH Supported Palladium Catalyst

Hydrotalcite-like compounds (HTlcs), which is also known as layered double hydroxides (LDHs), has a lot of properties such as adjustable degeneration about shelves anions, alkaline, thermal stability. Take advantage of the exchangeability of anions in LDHs, different kinds of anions can be inserted into the layer of LDHs to produce new LDHs with different functions. Due to the special properties, LDHs are widely used in the fields of catalyst, basic supports and other aspects.As an important anti-inflammatory allergy and asthma drug, montelukast sodium has a broad market prospects. The Heck reaction is a very critical step in the synthesis of montelukast sodium. After the completion of the reaction, the traditional catalyst PdCl2is difficult to be separated from the product and seriously affect the quality of the drugs. Therefore, the invention of an easy separation catalyst has an important significance for the synthsis of montelukast soudium and other Heck reactions.The LDHs containing palladium and NO3--, DS---------embedded layered double hydroxides precursor were prepared by coprecipitation method. Take advantage of the exchangeability of anions in LDH, the exchange of NO3-, DS-by PdCl42-in the layers of LDH precursor was carried out to produce PdCl42-intercalated LDH, which was then reduced to prepare LDH supported palladium catalyst. The precursor and intercalates had been characterized and analyzed by means of XRD, FT-IR, TG-DTA and ICP. The characterization results confirmed that the samples had a single polymorph and good crystllinity.The catalysts were used to catalyze the Heck reaction in the synthesis of montelukast sodium. The results showed that LDH-NO3-Pd0was the most favorable catalyst and can be separated from the products easily.