product residue in certain embodiments therefore it is preferred to run the reaction without catalyst however the use of sncl 4 may be preferred in embodiments in which ch 3 cf 2 ch 2 cl is the desired product since its use may allow a lower temperature to be used and result in a higher percentage of ch 3 cf 2 ch 2 cl in the crude product the photochlorination of ch 3 cf 2 ch 3 to ch 3 cf 2 ccl 3 has been mentioned in jacs 59 1937 2436 which is incorporated herein by reference the photochlorination was done using a 100 w hg lamp placed in a quartz jacket that was cooled with the use of a circulating cooling bath set at about u2212 5 u00b0 c the quartz jacket was inserted into a glass reactor of about 400 ml capacity the reactor was cooled externally by placing it in a glycol water bath which was cooled with the use of cooling coils connected to a second circulating bath set at u2212 8 5 c the reactor was fitted with a thermocouple stir bar and a gas inlet tube for introducing chlorine gas from a cylinder via a calibrated flowmeter exiting gases passed through a water cooled condenser an air trap and a scrubber containing naoh and na2so3 to remove.