# US 2025/0084019 A1 · Process for the preparation of 2,3,3,3-tetrafluoropropene > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0084019 A1 - Document ID: US20250084019A1 - Status: Published application - Kind: A1 - Application number: 18/953,347 - Filed: 2024-11-20 - Published: 2025-03-13 - Earliest claimed: 2008-05-15 - Assignees: Mexichem Amanco Holdings S.A. De C.V. - Applicants: Mexichem Amanco Holdings S.A. de C.V. - Inventors: John W. Smith; Claire McGuinness; Andrew P. Sharratt; Andrew Taylor - Web page: https://patentgrep.com/patent/US20250084019A1 ## CPC - C07C 17/25: by splitting-off hydrogen halides from halogenated hydrocarbons - C07C 17/354: by hydrogenation - C07C 21/18: containing fluorine - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS ## Abstract The invention provides a process for the preparation of 1234yf comprising (a) contacting 1,1,2,3,3,3-hexafluoropropene (1216) with hydrogen in the presence of a hydrogenation catalyst to produce 1,1,2,3,3,3-hexafluoropropane (236ea); (b) dehydrofluorinating 236ea to produce 1,2,3,3,3-pentafluoropropene (1225ye); (c) contacting 1225ye with hydrogen in the presence of a hydrogenation catalyst to produce 1,2,3,3,3-pentafluoropropane (245eb); and (d) dehydrofluorinating 245eb to produce 1234yf. ## Claims ### Claim at position 1 1-20. (canceled) ### Claim 21 A process for the preparation of 1,2,3,3,3-pentafluoropropene (1225ye), the process comprising: (a) contacting 1,1,2,3,3,3-hexafluoropropene (1216) with hydrogen in the presence of a hydrogenation catalyst to produce 1,1,2,3,3,3-hexafluoropropane (236ea); and (b) dehydrofluorinating 236ea to produce 1,2,3,3,3-pentafluoropropene (1225ye); wherein step (a) is carried out with a diluent gas stream that comprises a molar excess of about 42% to 380% of feedstock 1216. ### Claim 22 (depends on 21) The process according to claim 21, wherein the product from step (b) is further subjected to a distillation step. ### Claim 23 (depends on 21) The process according to claim 21, wherein step (b) is carried out in the vapor phase. ### Claim 24 (depends on 21) The process according to claim 21, wherein step (b) is carried out in the presence of HF. ### Claim 25 (depends on 24) The process according to claim 24, wherein the molar ratio of HF:organics is from about 0.01 to about 50:1. ### Claim 26 (depends on 21) The process according to claim 21, wherein step (b) is carried out in a reactor so that HF is being removed from the reactor as the HF is being produced. ### Claim 27 (depends on 21) The process according to claim 21, wherein step (a) is carried out in the vapor phase at a temperature of from about 0 to about 250° C. ### Claim 28 (depends on 21) The process according to claim 21, wherein the hydrogenation catalyst in step (a) comprises a supported or unsupported transition metal selected from Ni, Pd, Pt, Re, Rh, Ru, and mixtures thereof, and is used in an amount of from about 0.01 to about 30% by weight based on the total weight of the components that make up step (a). ### Claim 29 (depends on 28) The process according to claim 28, wherein the hydrogenation catalyst is supported on alumina; titania; silica; zirconia; fluorides of alumina, titania, silica, or zirconia; calcium fluoride; carbon; and/or barium sulfate. ### Claim 30 (depends on 21) The process according to claim 21, wherein step (b) is carried out at a temperature of from about 0 to about 400° C. and a presence of from about 0.01 to about 25 bara. ### Claim 31 (depends on 21) The process according to claim 21, wherein step (b) is carried out in the presence of a catalyst comprising activated carbon, a main group metal, and/or a transition metal. ### Claim 32 (depends on 21) The process according to claim 21, wherein step (b) is carried out in the presence of a catalyst based on chromia. ### Claim 33 (depends on 21) The process according to claim 21, wherein step (a) is performed in the presence of a diluent gas stream. ### Claim 34 (depends on 33) The process according to claim 33, wherein the diluent gas stream comprises one or more gases selected from the group consisting of nitrogen, 1,1,1,2-tetrafluoroethane (134a), excess HFP, excess 1225ye, excess 236a, and mixtures thereof. ### Claim 35 (depends on 21) The process according to claim 21, wherein the product of step (b) is subjected to an HF removal step and a drying step. ### Claim 36 (depends on 21) The process according to claim 21, wherein the HF removal step comprises scrubbing with water and/or aqueous base. ### Claim 37 A process for the preparation of 1,2,3,3,3-pentafluoropropene (1225ye), the process comprising: (a) contacting 1,1,2,3,3,3-hexafluoropropene (1216) with hydrogen in the presence of a hydrogenation catalyst to produce 1,1,2,3,3,3-hexafluoropropane (236a); and (b) dehydrofluorinating 236a to produce 1,2,3,3,3-pentafluoropropene (1225ye); wherein a product from step (a) and/or (b) is subjected to a purification step; wherein step (b) is carried out in the presence of a base selected from sodium hydroxide and potassium hydroxide; and wherein step (b) is carried out in the presence of water as a solvent. ### Claim 38 (depends on 37) The process according to claim 37, wherein the purification for step (a) comprises a distillation and/or condensation step. ### Claim 39 (depends on 37) The process according to claim 37, wherein the hydrogenation catalyst in step (a) comprises a supported or unsupported transition metal selected from Ni, Pd, Pt, Re, Rh, Ru, and mixtures thereof, and is used in an amount of from about 0.01 to about 30% by weight based on the total weight of the components that make up step (a). ### Claim 40 A process for the preparation of 1,2,3,3,3-pentafluoropropene (1225ye), the process comprising: (a) contacting 1,1,2,3,3,3-hexafluoropropene (1216) with hydrogen in the presence of a hydrogenation catalyst to produce 1,1,2,3,3,3-hexafluoropropane (236a); and (b) dehydrofluorinating 236a to produce 1,2,3,3,3-pentafluoropropene (1225ye); wherein step (a) is carried out at a temperature of from about 0 to about 250° C.; wherein a product from step (a) and/or (b) is subjected to one or more purification steps; wherein the one or more purification steps for step (b) comprises scrubbing with water or aqueous base, and a drying step; wherein the purification step for step (a) comprises a distillation step; and wherein steps (a) and (b) are carried out in the vapor phase.