# US 8,772,525 B2 · Method for preparing a diorganodihalosilane > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,772,525 B2 - Document ID: US8772525B2 - Status: Granted - Kind: B2 - Application number: 13/639,518 - Filed: 2011-03-31 - Published: 2013-03-14 - Granted: 2014-07-08 - Earliest claimed: 2010-05-28 - Assignees: Dow Corning Corporation - Applicants: Dimitris Katsoulis; Robert Larsen - Inventors: Dimitris Katsoulis; Robert Larsen - Web page: https://patentgrep.com/patent/US8772525B2 ## CPC - C07F 7/125: {by reactions involving both Si-C and Si-halogen linkages, the Si-C and Si-halogen linkages can be to the same or to different Si atoms, e.g. redistribution reactions} - C07F 7/122: {by reactions involving the formation of Si-C linkages (hydrosilylation reactions C07F7/14; direct synthesis C07F7/16)} - C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22) ## Abstract A method of preparing a diorganodihalosilane comprising the separate and consecutive steps of (i) contacting a copper catalyst with a mixture comprising hydrogen gas and a silicon tetrahalide at a temperature of from 500 to 1400° C. to form a silicon-containing copper catalyst comprising at least 0.1% (w/w) of silicon, wherein the copper catalyst is selected from copper and a mixture comprising copper and at least one element selected from gold, magnesium, calcium, cesium, tin, and sulfur; and (ii) contacting the silicon-containing copper catalyst with an organohalide at a temperature of from 100 to 600° C. to form at least one diorganodihalosilane. ## Claims ### Claim 1 A method of preparing a diorganodihalosilane, the method comprising the following separate and consecutive steps: (i) contacting a copper catalyst with a mixture comprising hydrogen gas and a silicon tetrahalide at a temperature of from 500 to 1400° C. to form a silicon-containing copper catalyst comprising from 1 to 5% (w/w) of silicon, wherein the copper catalyst is selected from copper and a mixture comprising copper and at least one element selected from gold, magnesium, calcium, cesium, tin, and sulfur; and (ii) contacting the silicon-containing copper catalyst with an organohalide at a temperature of from 100 to 600° C. to form at least one diorganodihalosilane. ### Claim 2 (depends on 1) The method according to claim 1, further comprising (iii) contacting the silicon-containing copper catalyst contacted with the organohalide in step (ii) with the mixture comprising hydrogen gas and a silicon tetrahalide at a temperature of from 500 to 1400° C. to reform the silicon containing copper catalyst comprising at least 0.1% (w/w) silicon; and (iv) contacting the reformed silicon-containing copper catalyst with the organohalide at a temperature of from 100 to 600° C. to form at least one diorganodihalosilane. ### Claim 3 (depends on 2) The method according to claim 2, further comprising repeating steps (iii) and (iv) at least 1 time. ### Claim 4 (depends on 2) The method according to claim 2, further comprising purging prior to the contacting of the reformed silicon-containing copper catalyst with the organohalide in step (iv). ### Claim 5 (depends on 4) The method according to claim 4, wherein the purging is conducted with argon or silicon tetrachloride. ### Claim 6 (depends on 1) The method according to claim 1, further comprising purging prior to contacting the silicon-containing copper catalyst with the organohalide in step (ii). ### Claim 7 (depends on 6) The method according to claim 6, wherein the purging is conducted with argon or silicon tetrachloride. ### Claim 8 (depends on 1) The method according claim 1, wherein the copper catalyst is supported. ### Claim 9 A method of preparing a diorganodihalosilane, the method comprising the following separate and consecutive steps: (i) contacting a copper catalyst with a mixture comprising hydrogen gas and a silicon tetrahalide at a temperature of from 500 to 1400° C. to form a silicon-containing copper catalyst comprising, from 1 to 5% (w/w) of silicon wherein the copper catalyst comprises from 0.1 to 35% (w/w) of a mixture and the mixture comprises copper, gold and magnesium, and (ii) contacting the silicon-containing copper catalyst with an organohalide at a temperature of from 100 to 600° C. to form at least one diorganodihalosilane. ### Claim 10 (depends on 8) The method according to claim 8, wherein the support is activated carbon. ### Claim 11 (depends on 1) The method according to claim 1, wherein mole ratio of hydrogen to silicon tetrahalide is from 20:1 to 5:1. ### Claim 12 (depends on 1) The method according to claim 1, wherein the silicon tetrahalide is silicon tetrachloride. ### Claim 13 (depends on 1) The method according to claim 1, wherein the organohalide has formula Rx, where R is C1-C10 alkyl or C4-C10 cycloalkyl and X is fluoro, chloro, bromo, or iodo. ### Claim 14 (depends on 13) The method of claim 13, wherein R is methyl and X is chloro. ### Claim 15 (depends on 1) The method according to claim 1, wherein the contacting in (ii) is in the absence of hydrogen. ### Claim 16 (depends on 1) The method according to claim 1, wherein the diorganodihalosilane has the formula R2SiX2, where R is C1-C10 alkyl or C4-C10 cycloalkyl and X is fluoro, chloro, bromo, or iodo. ### Claim 17 (depends on 16) The method according to claim 16, wherein R is methyl and X is chloro. ### Claim 18 (depends on 1) The method according to claim 1, further comprising recovering the diorganodihalosilane. ### Claim 19 (depends on 1) The method according to claim 1, wherein the residence time of the hydrogen and silicon tetrahalide is from 0.5 to 10 s and the residence time of the organohalide is from 1 to 10 s.