| abstract |
PURPOSE: To obtain a biaryl compound in high yield by dehalogenating and dimerizing an aromatic halogen compound having a halogen atom on carbon atom of the aromatic nucleus in the presence of a catalyst containing Pd and iron supported on a carrier, water, a reducing agent and halogen acceptor. n CONSTITUTION: An aromatic halogen compound (e.g. 4-chloro-o-phthalic acid) having a halogen atom on carbon atom of the aromatic nucleus is dehalogenated and dimerized in the presence of a catalyst, water, a reducing agent and a halogen acceptor to afford a biaryl compound (e.g. an alkali metal 3,4,3',4'- biphenyltetracarboxylate). In the process, a catalyst containing a Pd compound and an iron compound (e.g. palladium chloride and ferrous chloride) supported on a carrier such as active carbon is used as the catalyst to carry out the reaction at 50-200°C. The amount of the catalyst used is 30-0.1 mg atom expressed in terms of Pd atom based on 1 mol raw material. The objective substance can be obtained in high yield for a long period by using the aforementioned catalyst. n COPYRIGHT: (C)1991,JPO&Japio |