The invention relates to an improved process for preparing bromochloromethane by reacting dichloromethane and dibromomethane in the presence of catalysts.

The invention relates to an improved process for preparing bromochloromethane by reacting dichloromethane and dibromomethane in the presence of catalysts.

##STR00001##

Disclosed herein is a salt of formula I: where R.sup.1, X, n, R, R.sup.1, Y, m, p, q, Z and o are as defined herein. Also disclosed herein are methods of using said salts in chemical synthesis, such as to prepare compounds isotopically enriched in 18F for use in PET & imaging, as well as methods to make the compounds of formula I.

##STR00001##

Disclosed herein is a salt of formula I: where R.sup.1, X, n, R, R.sup.1, Y, m, p, q, Z and o are as defined herein. Also disclosed herein are methods of using said salts in chemical synthesis, such as to prepare compounds isotopically enriched in 18F for use in PET & imaging, as well as methods to make the compounds of formula I.

Disclosed is a method for improving the stability of a catalyst in recycling HFC-23. The recycling is realized by means of a fluorine-chlorine exchange reaction with HFC-23 and a halogenated hydrocarbon. The catalyst for the fluorine-chlorine exchange reaction comprises a main body catalyst and a metal oxide, wherein the metal oxide is selected from at least one metal oxide of K, Na, Fe, Co, Cu, Ni, Zn or Ti, and has an addition amount of 0.1-5 wt %. The present invention has advantages such as a good catalyst stability, a long life, and a low content of by-product CFC-12.

Disclosed is a method for improving the stability of a catalyst in recycling HFC-23. The recycling is realized by means of a fluorine-chlorine exchange reaction with HFC-23 and a halogenated hydrocarbon. The catalyst for the fluorine-chlorine exchange reaction comprises a main body catalyst and a metal oxide, wherein the metal oxide is selected from at least one metal oxide of K, Na, Fe, Co, Cu, Ni, Zn or Ti, and has an addition amount of 0.1-5 wt %. The present invention has advantages such as a good catalyst stability, a long life, and a low content of by-product CFC-12.

Disclosed is a method for reducing carbon deposits on a catalyst in recycling HFC-23. The recycling is realized by means of a fluorine-chlorine exchange reaction with HFC-23 and a halogenated hydrocarbon. The catalyst for the fluorine-chlorine exchange reaction comprises a main body catalyst and a precious metal. The precious metal is selected from at least one of Pt, Pd, Ru, Au or Rh, and has an addition amount of 0.01-2 wt %. During the fluorine-chlorine exchange reaction, hydrogen gas is introduced. The invention has advantages of good catalyst stability, long life, etc.

Disclosed is a method for reducing carbon deposits on a catalyst in recycling HFC-23. The recycling is realized by means of a fluorine-chlorine exchange reaction with HFC-23 and a halogenated hydrocarbon. The catalyst for the fluorine-chlorine exchange reaction comprises a main body catalyst and a precious metal. The precious metal is selected from at least one of Pt, Pd, Ru, Au or Rh, and has an addition amount of 0.01-2 wt %. During the fluorine-chlorine exchange reaction, hydrogen gas is introduced. The invention has advantages of good catalyst stability, long life, etc.

The present invention provides a process for preparing at least one chlorinated alkene from at least one chlorinated alkane, using an aqueous base in a jet loop reactor.

The present invention provides a method of converting a brominated hydrocarbon to a chlorinated hydrocarbon that involves contacting together the brominated hydrocarbon and a chlorinated ion exchange resin that has a water content of less than or equal to 30 percent by weight, based on the total weight of the chlorinated ion exchange resin and the water. The brominated hydrocarbon includes at least one replaceable bromo group, where each replaceable bromo group is independently covalently bonded to an sp.sup.3 hybridized carbon. Contact between the brominated hydrocarbon and the chlorinated ion exchange resin results in replacement of at least one replaceable bromo group of the brominated hydrocarbon with a chloro group, and correspondingly conversion of at least a portion of the brominated hydrocarbon to the chlorinated hydrocarbon.