What are the Synthetic Methods of Pyromellitic Dianhydride?

Release time:

2024-07-09

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Pmellitic dianhydride (PMDA) is an important organic synthesis intermediate, polymers, drugs.

Pyromellitic dianhydride (PMDA) is an important organic synthesis intermediate, which is widely used in dyes, polymers, drugs and other fields. It can be synthesized with various methods, and the common methods are as follows:

1. Phthalic acid and acetic anhydride are esterified in the presence of thionyl chloride to produce dimethyl terephthalat, which is further oxidized and cracked to get PMDA.

2. The reaction of phthalic acid with anhydrous thionyl chloride at high temperature produces trioctyl trimellitate, and then PMDA is obtained by reduction reaction.

3. Condensation reaction of phthalic acid and aniline to produce terephthalic acid diphenylamine, and then then PMDA is obtained by oxidation reaction.

4. Benzene reacts with chlorine in the presence of thionyl chloride to produce chlorinated benzene, and then reacts with acetic anhydride to produce phenylacetyl chloride, and then PMDA is obtained by oxidation reaction.

5. Aniline reacts with carbonic anhydride in the presence of thionyl chloride to produce benzamide, and then PMDA is obtained by oxidation reaction.

The above are some commonly-seen methods for synthesizing PMDA, and different methods have their own characteristics and scope of applications. In practical applications, suitable synthetic routes can be selected according to specific needs to improve synthesis efficiency and product quality. The large-scale industrial production of PMDA is a complex chemical process, which requires careful control of reaction conditions and production processes to ensure stable product quality and production efficiency.

Usage of Pyromellitic Dianhydride

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