Process for the halogenation of 3,3,3-trifluoropropene

1. A process for preparing a compound of formula CF3CHFCH2X, where X is Cl or F, comprising contacting the 3,3,3-trichloropropene (1243zf) with a compound of formula AB selected from Cl2, Br2, I2, ClF, ClBr and ICl, HF and catalyst in the presence tsinkhromovogo to form a compound of formula CF3CHFCH2X. 2. The method of claim 1, which is carried out at a pressure of from about 100 to about 2000 kPa (1-20 bar). 3. The method of claim 1, which is carried out at a temperature from about 50 ° C to about 400 ° C. 4. The method of claim 1 wherein the compound of formula AB represents Cl2. 5. The method of claim 1, wherein the molar ratio of 1243zf: compound of formula AB is from about 10: 1 to about 1: 5. 6. The method of claim 5, wherein the molar ratio of 1243zf: compound of formula AB is from about 5: 1 to about 1: 2. 7. The method of claim 1 wherein HF is used in molar excess compared to the amount of 1243zf and / or a compound of formula AB. 8. The method of claim 7, wherein the molar ratio of HF: 1243zf is from about 2: 1 to about 150: 1. 9. A method according to any one of the preceding claims, wherein tsinkhromovy catalyst is an oxide, oxyfluoride or fluoride of chromium, comprising zinc or a zinc compound. 10. The method of claim 9 wherein tsinkhromovy catalyst is an oxide, oxyfluoride or fluoride of chromium, comprising zinc or a zinc compound in an amount from about 0.01 wt.% To about 25 wt.%.