Patent ID: 8008521

Claim:
A process for the production of a tri-organo-monochlorosilane of the general formula (XIIa) (R 1 )(R 2 )(R 3 )SiCl (XIIa) wherein R 1 , R 2 and R 3 are the same as or different from each other and each is a primary, secondary or tertiary alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aralkyl group or an aryl group, but wherein R 1 , R 2 and R 3 each and all do not represent methyl group at the same time, or for the production of a tri-organo monochlorosilane of the general formula (XIIb) (R 1 )(R 2 )(R 3a )SiCl (XIIb) wherein R 1 and R 2 have the same meanings as defined above and R 3a is a secondary alkyl group or a tertiary alkyl group or a cycloalkyl group, or R 3a is an alkyl-substituted aromatic hydrocarbon group of which the alkyl substituent is bonding to a carbon atom present in the aromatic hydrocarbon group characterized in that the process comprises reacting hydrochloric acid with a tri-organosilane compound of the formula (XIa) (R 1 )(R 2 )(R 3 )SiZ 1 (XIa) where R 1 , R 2 and R 3 each have the same meanings as defined above and Z 1 is a hydrolyzable group, or with a tri-organosilane compound containing the bulky hydrocarbon group R 3a therein and having the formula (XIb) (R 1 )(R 2 )(R 3a )SiZ 2 (XIb) where R 1 , R 2 and R 3a have the same meanings as defined above and Z 2 is a primary or secondary alkyloxy group, a cycloalkyloxy group or an aralkyloxy group, or Z 2 is a 2-substituted or unsubstituted-2-chloroethoxy group of the formula (A) where R 4 is a hydrogen atom or an alkyl group of 1-8 carbon atoms, or R 4 is an alkoxymethylene group, an alkenyloxymethylene group or an aryloxy-methylene group of the formula —CH 2 —O—R 5 where R 5 is a straight or branched chain alkyl group of 1-20 carbon atoms or an alkenyl group of 2-10 carbon atoms or an aryl group, thereby to produce a tri-organo-monochlorosilane of the formula (XIIa) or a tri-organo-monochlorosilane of the formula (XIIb).