Production processes for triorganomonoalkoxysilanes and triorganomonochlorosilanes

A process for the production of a tri-organo-mono (alkoxy, cycloalkyloxy or aralkyloxy) silane containing one, two, or three of a bulky hydrocarbon group or groups R therein, the tri-organo-mono(alkoxy, cycloalkyloxy or aralkyloxy) silane having the formula (III)

• R3-(X+Y)(R1)x(R2)ySi(OR3) (III)
• wherein
• R is a secondary alkyl group, a tertiary alkyl group or a cycloalkyl group, or
• R is an alkyl-substituted aromatic hydrocarbon group as defined below;
• R1 is a primary, secondary or tertiary alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group or an aralkyl group;
• R2 is a secondary alkyl group, a tertiary alkyl group, a cycloalkyl group or an aryl group;
• R3 is a primary or secondary alkyl group, a cycloalkyl group or an aralkyl group, or the group —OR3 is a 2-substituted or unsubstituted-2chloroethoxy group of the formula (A)
• wherein R4 is a hydrogen atom or an alkyl group of 1-8 carbon atoms, or R4 is an alkoxymethylene group, an alkenyloxymethylene group or an aryloxymethylene group of the formula —CH2—O—R5,
• where R5 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;
• and
• x is an integer of 0 or 1 and y is an integer of 0, 1 or 2, provided that these integers for x and y are to be within the range of 0<(x+y)<2,
• the process comprising:
• reacting an organo-unsubstituted or mono-organo or di-organo-mono(alkoxy, cycloalkyloxy or aralkyloxy)-tri, di or monochlorosilane of the formula (I)
• (R1)x(R2)ySiCl3-(x+y)(OR3) (I)
• wherein R1, R2, R3, x and y have the same meanings as defined above, with a Grignard reagent of the formula (II)
• RMgX (II)
• wherein R is a secondary alkyl group, a tertiary alkyl group or a cycloalkyl group as defined above, or R is an alkyl-substituted aromatic hydrocarbon group of which the alkyl substituent is bonding to a carbon atom present in the aromatic hydrocarbon group, with said carbon atom being adjacent to the carbon atom of the aromatic hydrocarbon group that is bonding to the magnesium atom, and X is a chlorine, bromine or iodine atom in the absence of any coupling catalyst for the progress of the intended Grignard reaction.