Efficient Catalysis of 2-Acetylthiophene over Aluminum Phosphotungstate Catalyst

2-acetylthiophene is an important intermediate in organic synthesis. It has been widely used in the synthesis of medicines and pesticides, such as antibiotics, plant growth regulators, androgen inhibitors, fungicides and herbicides.

With the rapid development of molecular tailoring technology in recent years, new catalytic materials emerge in endlessly. The use of heteropoly acids and their Heteropoly salts as catalysts for alkylation and acylation has attracted more and more attention. For example, supported tungsten heteropoly acids, whose catalytic performance can be adjusted by changing the molecular composition and structure of heteropoly acids to meet the requirements of specific catalytic processes.

Some researchers have prepared a high specific surface area aluminum phosphotungstate catalyst, which can catalyze the synthesis of 2-acetylthiophene with high yield and selectivity under mild conditions. The preparation process of this catalyst is as follows:

Ten grams of phosphotungstic acid and 0.75 grams of aluminium nitrate were mixed into aqueous solutions of 0.08 mol/L and 0.1 mol/L, respectively. Then the 0.1 mol/L aluminium nitrate solution was added to 0.08 mol/L phosphotungstic acid solution dripping by dripping at a rate of 1 milliliter/minute, and stirred strictly at room temperature. After half an hour of stirring, the water was kept at room temperature for 2 hours. The water evaporated to dry at 80 degrees C and then dried to about 100 degrees C. Dry AlPW₁₂O₄₀ was prepared by drying. The specific surface area was determined by BET method to be 0.34 m²/g.

Compared with the traditional method, the supported aluminum phosphotungstate catalyst has the advantages of high yield (91% yield of 2-acetylthiophene), good selectivity (99.65% selectivity of 2-acetylthiophene), short reaction time, low reaction temperature, low energy consumption and good reusability. After four repeated experiments, the activity of the catalyst remains above 71%. The selectivity of reused catalysts is over 99.67% each time. Solvent-free reaction system is adopted. By-product acetic acid and thiophene can be recovered. There is basically no "three wastes" pollution problem, and the economic and social benefits are remarkable.

• < Prev
• Next >