| 摘要 |
PURPOSE:To readily obtain the titled compound useful as a raw material for medicines, agricultural chemicals, etc., from a readily available raw material in high yield, by reacting a nuclear chlorinated and fluorinated benzotrifluoride with an dechlorinating agent in the presence of a dechlorination catalyst. CONSTITUTION:A compound expressed by formula I (m and n are integers of 1-4 and 2<=m+n<=5), e.g. 3-chloro-4,5-difluorobenzotrifluoride, is reacted with a dechlorinating agent, preferably H2 in the presence of a dechlorination catalyst, preferably palladium-carbon normally at 20-200 deg.C, preferably 70-130 deg.C to advantageously afford the aimed compound expressed by formula II (p is an integer of 1-n) while improving disadvantages of well-known processes, e.g. danger of using HF at high temperatures, formation of hardly separable isomers, etc. In the above-mentioned method, since the boiling point difference between the raw material and the product is large, the purification is readily carried out and the high-purity aimed compound can be obtained without using a complicated purification step. |
