Patent ID: 8772554

Claim:
A process for preparing 2,3,3,3-tetrafluoropropene, comprising the step of: (1) in a reactor, (1-1) reacting 1,1,1,2,3-pentachloropropane with hydrogen fluoride in an amount of 10 to 100 mol per mole of the 1,1,1,2,3-pentachloropropane; (1-2) in the presence of chromic oxide represented by composition formula: CrOm (1.5<m<3) or fluorinated chromic oxide obtained by fluorinating the chromic oxide; (1-3) in the presence of oxygen in an amount of 0.02 to 1 mol per mole of the 1,1,1,2,3-pentachloropropane; and (1-4) in the gas phase within a temperature range of 320 to 390° C., thereby obtaining a reaction product containing 2,3,3,3-tetrafluoropropene.