# US 11,261,146 B2 · Preparation of 2,3,3,3-tetrafluoropropene and intermediates thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,261,146 B2 - Document ID: US11261146B2 - Status: Granted - Kind: B2 - Application number: 17/282,446 - Filed: 2019-10-03 - Published: 2021-12-09 - Granted: 2022-03-01 - Earliest claimed: 2018-10-04 - Assignees: SRF Limited - Applicants: Srf Limited - Inventors: Sarathy Iyengar; Sridhar Jeyaraman; Karthic Natarajan; Nathan Rajamani; Rahul Saxena; Anurag Jain - Web page: https://patentgrep.com/patent/US11261146B2 ## CPC - C07C 17/25: by splitting-off hydrogen halides from halogenated hydrocarbons - B01J 21/04: Alumina - B01J 23/26: Chromium - C07C 17/087: to unsaturated halogenated hydrocarbons - C07C 17/206: {the other compound being HX} - C07C 17/275: of hydrocarbons and halogenated hydrocarbons - C07C 17/278: of only halogenated hydrocarbons - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract The present invention provides a process for preparation of 2,3,3,3-tetrafluoropropene and intermediates thereof. Owing to its low global warming potential and zero ozone depleting potential, it is been proposed as a replacement for existing chlorofluorocarbons and hydrofluorocarbons as refrigerant. ## Claims ### Claim 1 A process for preparation of 2,3,3,3-tetrafluoropropene, comprising the steps of: a) reacting carbon tetrachloride with ethylene in presence of a metallic catalyst and an organic ligand to obtain a reaction mixture 1, comprising 1,1,1,3-tetrachloropropane; b) de-hydrohalogenating the reaction mixture 1 to obtain a reaction mixture 2 comprising 1,1,3-trichloroprop-1-ene and 3,3,3-trichloroprop-1-ene; c) fluorinating the reaction mixture 2 using a gaseous composition of fluorine and nitrogen in the presence of anhydrous hydrogen fluoride to obtain a reaction mixture 3, comprising trichlorodifluoropropanes of formula 1, X2CH2CHFCCl2X1, wherein X1 and X2 represents chlorine or fluorine; provided that X1 is not same as X2; and d) simultaneous fluorination and de-hydrohalogenation of the reaction mixture 3 to obtain 2,3,3,3-tetrafluoropropene. ### Claim 2 A process for preparation of 2,3,3,3-tetrafluoropropene, comprising the steps of: a) de-hydrohalogenating 1,1,1,3-tetrachloropropane to obtain a reaction mixture 2, comprising 1,1,3-trichloroprop-1-ene and 3,3,3-trichloroprop-1-ene; b) fluorinating the reaction mixture 2 using a gaseous composition of fluorine and nitrogen in the presence of anhydrous hydrogen fluoride to obtain a reaction mixture 3, comprising trichlorodifluoropropanes of formula 1, X2CH2CHFCCl2X1, wherein X1 and X2 represents chlorine or fluorine; provided that X1 is not same as X2; and c) simultaneous fluorination and de-hydrohalogenation of the reaction mixture 3 to obtain 2,3,3,3-tetrafluoropropene. ### Claim 3 A process for preparation of 2,3,3,3-tetrafluoropropene, comprising the step of: a) fluorinating a reaction mixture comprising 1,1,3-trichloroprop-1-ene and 3,3,3-trichloroprop-1-ene using a gaseous corn position of fluorine and nitrogen in the presence of anhydrous hydrogen fluoride, to obtain a reaction mixture 3, comprising trichlorodifluoropropanes of formula 1, X2CH2CHFCCl2X1, wherein X1 and X2 represents chlorine or fluorine; provided that X1 is not same as X2; and b) simultaneous fluorination and de-hydrohalogenation of the reaction mixture 3 to obtain 2,3,3,3-tetrafluoropropene. ### Claim 4 A process for preparation of 2,3,3,3-tetrafluoropropene, comprising a step of simultaneously fluorination and de-hydrohalogenation of a mixture comprising trichlorodifluoropropanes of formula 1, X2CH2CHFCCl2X1, wherein X1 and X2 represents chlorine or fluorine; provided that X1 is not same as X2; to obtain 2,3,3,3-tetrafluoropropene. ### Claim 5 A process for preparation of trichlorodifluoropropanes of formula 1, X2CH2CHFCCl2X1, wherein X1 and X2 represents chlorine or fluorine; provided that X1 is not same as X2, comprising the steps of: a) reacting carbon tetrachloride with ethylene in presence of a metallic catalyst to obtain a reaction mixture 1, comprising 1,1,1,3-tetrachloropropane; b) de-hydrohalogenating the reaction mixture 1 to obtain a reaction mixture 2, comprising 1,1,3-trichloroprop-1-ene and 3,3,3-trichloroprop-1-ene; c) fluorinating the reaction mixture 2 using a gaseous composition of fluorine and nitrogen in the presence of anhydrous hydrogen fluoride, to obtain a compound of formula 1. ### Claim 6 A process for preparation of trichlorodifluoropropanes of formula 1, X2CH2CHFCCl2X1, wherein X1 and X2 represents chlorine or fluorine; provided that X1 is not same as X2, comprising the steps of: a) de-hydrohalogenating 1,1,1,3-tetrachloropropane to obtain a reaction mixture 2, comprising 1,1,3-trichloroprop-1-ene and 3,3,3-trichloroprop-1-ene; b) fluorinating the reaction mixture 2 using a gaseous composition of fluorine and nitrogen in the presence of anhydrous hydrogen fluoride, to obtain a compound of formula 1. ### Claim 7 A process for preparation of trichlorodifluoropropanes of formula 1, X2CH2CHFCCl2X1, wherein X1 and X2 represents chlorine or fluorine; provided that X1 is not same as X2, comprising the steps of, fluorinating a mixture comprising 1,1,3-trichloroprop-1-ene and 3,3,3-trichloroprop-1-ene using a gaseous composition of fluorine and nitrogen in the presence of anhydrous hydrogen fluoride to obtain a compound of formula 1. ### Claim 8 (depends on 1) The process as claimed in claim 1, wherein the metallic catalyst is selected from a group consisting of cuprous chloride, cuprous bromide, cuprous cyanide, cuprous sulfate, ferrous chloride, ferric chloride and tris (2,2′-bipyridine) iron (II) hexafluorophosphate. ### Claim 9 (depends on 1) The process as claimed in claim 1, wherein the organic ligand is selected from a group consisting of trimethylphosphate, triethylphosphate, tributylphosphate, and triphenylphosphate. ### Claim 10 (depends on 1) The process as claimed in claim 1, wherein the step of de-hydrohalogenation is carried out using a base in the presence of a phase transfer catalyst. ### Claim 11 (depends on 10) The process as claimed in claim 10, wherein the base is selected from a group consisting of sodium hydroxide or potassium hydroxide. ### Claim 12 (depends on 10) The process as claimed in claim 10, wherein the phase transfer catalyst is selected from a group consisting of crown ethers, polyalkylene glycols, benzyltriethylammonium chloride, methyltrioctylammonium chloride, tetra-nbutylammonium chloride, tetra-n-butylammonium bromide, tetranbutylphosphonium chloride, bis [tris(dimethylamino) phosphine] iminium chloride, tetratris [tris(dimethylamino) phosphinimino] phosphonium chloride, and trioctylmethyl ammonium hydrogen sulfate. ### Claim 13 (depends on 1) The process as claimed in claim 1, wherein the step of simultaneous fluorination and de-hydrohalogenation is carried out by using hydrogen fluoride in the presence of co-precipitated chromia-alumina catalyst.