Photochlorination of 1,1,1,3,3-pentafluoropropane

A process for the preparation of substantially pure 1-chloro-1,1,3,3,3-pentafluoropropane, CF3CH2CF2Cl, comprising:

• (1) contacting in a reaction zone in the substantial absence of oxygen, at a temperature of from about −5° C. to about +10° C. reactants comprising chlorine and 1,1,1,3,3-pentafluoropropane, CF3CH2CHF2, wherein said CF3CH2CHF2 is substantially in the liquid phase and said chlorine is present in said liquid phase and is also present in the vapor phase;
• and
• (2) subjecting said reactants to actinic radiation wherein the source of said actinic radiation is a light source having a radiation spectrum of from about 2,000 to about 5,000 Angstroms;
• and wherein:
• (A) said molar ratio of chlorine to CF3CH2CHF2 is from about 0.2:1 to about 1.2:1;
• (B) inert gas is present in said reaction zone at a concentration equal to or less than about 5 wt. % of the total weight of said reactants;
• (C) the reactants and reaction products of step (1) are further subjected to contact with an aqueous solution of sodium bisulfite at a temperature of from about −5° C. to about +10° C.;
• and
• (D) the reactants and reaction products of step (B) are further subjected to at least one separation step selected from the group consisting of fractionation, distillation and liquid-liquid extraction.