Abstract: A method for preparing 2,3-dichloro-5-trifluoromethylpyridine, comprising at a temperature of 100˜150° C. and a pressure of 0.5˜5.0 MP, in presence of at least one catalyst selected from supported metal chloride, supported zeolite molecular sieve and supported heteropolyacid, 2-chloro-5-trifluoromethylpyridine reacts with chlorine gas to obtain 2,3-dichloro-5-trifluoromethylpyridine. The preparing method provided by the present invention has advantages such as high selectivity of desired product, high utilization rate of chlorine gas, moderate process condition, simple operation and less three wastes. The present invention also discloses a preparing method for preparing 2-chloro-5-trifluoromethylpyridine, which is capable of reducing unit consumption, reducing separation cost, and improving safety compared to the prior art.

Abstract: Disclosed in the present disclosure is a method for preparing 2,3,3,3-tetrafluoropropene. The method includes a two-step method for preparing 2,3,3,3-tetrafluoropropene, a method for co-producing 2,3,3,3-tetrafluoropropene and 1-chloro-2,3,3,3-tetrafluoropropene, and a method for co-producing 2,3,3,3-tetrafluoropropene and 1-chloro-3,3,3-trifluoropropene. The two-step method for preparing 2,3,3,3-tetrafluoropropene includes: A1, a telomerization step: subjecting chlorofluoromethane and trifluoroethylene to a pressure telomerization reaction under the action of a telomerization catalyst to prepare 3-chloro-1,1,1,2-tetrafluoropropane, wherein the telomerization catalyst is a Lewis acid catalyst or a mixed catalyst of a Lewis acid catalyst and dichloromethane; and A2, a dehydrochlorination step: subjecting the 3-chloro-1,1,1,2-tetrafluoropropane to dehydrochlorination under the catalytic action of activated carbon to obtain 2,3,3,3-tetrafluoropropene.

Abstract: The present invention provides a method for the preparing of 2-chloro-5-trifluoromethylpyridine, comprising two steps of chlorofluorination reaction and chlorination reaction, the chlorination catalyst used in the chlorination reaction was chosen from a fluoride, an oxide, a hydroxide, a carbonate, or a chloride of magnesium, calcium and barium and a supported palladium catalyst; or under the action of at least one catalyst chosen from ZSM-5, 5A, ? and 13× molecular sieves, 3-trifluoromethylpyridine and chlorine gas phase have reaction to obtain 2-chloro-5-trifluoromethylpyridine. Or, under the action of a catalyst chosen from a fluoride, an oxide, a hydroxide, a carbonate, or a chloride of magnesium, calcium, and barium and a supported palladium catalyst, 3-trifluoromethylpyridine and chlorine gas phase have reaction to obtain 2-chloro-5-trifluoromethylpyridine.

Abstract: A method for preparing 2,3-dichloro-5-trifluoromethylpyridine, comprising at a temperature of 100˜150° C. and a pressure of 0.5˜5.0 MP, in presence of at least one catalyst selected from supported metal chloride, supported zeolite molecular sieve and supported heteropolyacid, 2-chloro-5-trifluoromethylpyridine reacts with chlorine gas to obtain 2,3-dichloro-5-trifluoromethylpyridine. The preparing method provided by the present invention has advantages such as high selectivity of desired product, high utilization rate of chlorine gas, moderate process condition, simple operation and less three wastes. The present invention also discloses a preparing method for preparing 2-chloro-5-trifluoromethylpyridine, which is capable of reducing unit consumption, reducing separation cost, and improving safety compared to the prior art.

Abstract: The present invention discloses a method for preparing 2,3-dichloro-5-trifluoromethylpyridine, comprising at a temperature of 100˜150° C. and a pressure of 0.5˜5.0 MP, in presence of at least one catalyst selected from supported metal chloride, supported zeolite molecular sieve and supported heteropolyacid, 2-chloro-5-trifluoromethylpyridine reacts with chlorine gas to obtain 2,3-dichloro-5-trifluoromethylpyridine. The preparing method provided by the present invention has advantages such as high selectivity of desired product, high utilization rate of chlorine gas, moderate process condition, simple operation and less three wastes. The present invention also discloses a preparing method for preparing 2-chloro-5-trifluoromethylpyridine, which is capable of reducing unit consumption, reducing separation cost, and improving safety compared to the prior art.

Abstract: The present invention provides a method for the preparing of 2-chloro-5-trifluoromethylpyridine, comprising two steps of chlorofluorination reaction and chlorination reaction, the chlorination catalyst used in the chlorination reaction was chosen from a fluoride, an oxide, a hydroxide, a carbonate, or a chloride of magnesium, calcium and barium and a supported palladium catalyst; or under the action of at least one catalyst chosen from ZSM-5, 5A, ? and 13X molecular sieves, 3-trifluoromethylpyridine and chlorine gas phase have reaction to obtain 2-chloro-5-trifluoromethylpyridine. Or, under the action of a catalyst chosen from a fluoride, an oxide, a hydroxide, a carbonate, or a chloride of magnesium, calcium, and barium and a supported palladium catalyst, 3-trifluoromethylpyridine and chlorine gas phase have reaction to obtain 2-chloro-5-trifluoromethylpyridine.

Abstract: The present invention discloses a method for preparing 2,3-dichloro-5-trifluoromethylpyridine, comprising at a temperature of 100˜150° C. and a pressure of 0.5˜5.0 MP, in presence of at least one catalyst selected from supported metal chloride, supported zeolite molecular sieve and supported heteropolyacid, 2-chloro-5-trifluoromethylpyridine reacts with chlorine gas to obtain 2,3-dichloro-5-trifluoromethylpyridine. The preparing method provided by the present invention has advantages such as high selectivity of desired product, high utilization rate of chlorine gas, moderate process condition, simple operation and less three wastes. The present invention also discloses a preparing method for preparing 2-chloro-5-trifluoromethylpyridine, which is capable of reducing unit consumption, reducing separation cost, and improving safety compared to the prior art.