Method for Preparing a Diorganodihalosilane

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.

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 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.   
     
     
         2 . 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. 
     
     
         3 . The method according to  claim 2 , further comprising repeating steps (iii) and (iv) at least 1 time. 
     
     
         4 . 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), wherein optionally the purging is conducted with argon or silicon tetrachloride. 
     
     
         5 . The method according to  claim 1 , further comprising purging prior to contacting the silicon-containing copper catalyst with the organohalide in step (ii), wherein optionally the purging is conducted with argon or silicon tetrachloride. 
     
     
         6 . The method according to  claim 1 , wherein the copper catalyst is supported. 
     
     
         7 . The method according to  claim 1 , wherein the copper catalyst comprises from 0.1 to 35% (w/w) of the mixture. 
     
     
         8 . The method according to  claim 1 , wherein silicon tetrahalide has formula SiX 4 , where X is chloro. 
     
     
         9 . The method according to  claim 1 , wherein the organohalide has the formula RX, where R is C 1 -C 10  alkyl or C 4 -C 10  cycloalkyl and X is fluoro, chloro, bromo, or iodo. 
     
     
         10 . The method according to  claim 1 , wherein the contacting in (ii) is in the absence of hydrogen, silicon tetrahalide, or both hydrogen and silicon tetrahalide. 
     
     
         11 . The method according to  claim 1 , wherein the diorganodihalosilane has the formula R 2 SiX 2 , where R is C 1 -C 10  alkyl or C 4 -C 10  cycloalkyl and X is fluoro, chloro, bromo, or iodo. 
     
     
         12 . The method according to  claim 1 , further comprising recovering the diorganodihalosilane. 
     
     
         13 . 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 20% (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.   
     
     
         14 . The method of  claim 13 , 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; and wherein the method optionally further comprises repeating steps (iii) and (iv) at least 1 time. 
     
     
         15 . The method according to  claim 14 , wherein the copper catalyst is supported. 
     
     
         16 . The method according to  claim 15 , wherein the support is activated carbon. 
     
     
         17 . A method of preparing a diorganodihalosilane, the method comprising the following separate and consecutive steps:
 (i) contacting a supported 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 and further comprising a support, wherein the supported 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 the supported copper catalyst further comprises the support; 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.   
     
     
         18 . The method according to  claim 17 , 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; and wherein the method optionally further comprises repeating steps (iii) and (iv) at least 1 time. 
     
     
         19 . The method of  claim 17 , wherein the mixture is present, and the mixture comprises copper and gold.