Methods for producing diorganodialkoxysilanes

Claim 3

The method according to claim 1 wherein R 1 or R 2 is ##STR12## wherein y is 1 or 0; R 4 is alkyl having 1 to 7 carbon atoms; R 5 is alkyl having 1 to 7 carbon atoms; or R 4 and R 5 taken together with the carbon atom to which they are attached form a cycloalkyl group having 3 to 10 carbon atoms.

Claim 4

The method of selective production of dialkyldialkoxysilanes according to claim 1 wherein R 1 and R 2 are branched alkyl groups having 3 to 6 carbon atoms.

Claim 5

The method of selective production of dicycloalkyldialkoxysilanes according to claim 1, wherein R 1 and R 2 are cycloalkyl groups having 5 to 7 carbon atoms.

Claim 6

The method of selective production of alkylcycloalkyldialkoxysilanes according to claim 1, wherein R 1 is a branched alkyl group having 3 to 6 carbon atoms and R 2 is a cycloalkyl group having 5 to 7 carbon atoms.

Claim 10

The method of claim 1, wherein the reaction is conducted in methyl-tert-butylether.

Claim 11

The method of claim 1 which comprises quenching any excess Grignard reagent remaining after reaction with a stoichiometric amount of an alcohol R 3 OH thereby forming a side product R 3 OMgX.

Claim 12

The method of claim 1 wherein the effective amount of the Grignard reagent is present in a molar ratio of tetraalkoxysilane to Grignard reagent ranging from 1:2 to 1:10.

Claim 13

The method of claim 11 wherein the molar ratio range is from 1:2 to 1:5.

Claim 14

The method of claim 1 wherein the effective amount of the Grignard reagent is present in a molar ratio of monoorganotrialkoxysilane to Grignard reagent ranging from 1:1 to 1:10.

Claim 15

The method of claim 13 wherein the molar ratio ranges from 1:1 to 1:3.

Claim 16

The method of claim 1 wherein the monoorganotrialkoxysilane is sec-butyltrimethoxysilane, the Grignard reagent is isobutylmagnesium chloride and the product is isobutyl-sec-butyldimethoxysilane; the monoorganotrialkoxysilane is isobutyltrmethoxysilane, the Grignard reagent is n-propylmagnesium chloride and the product is isobutyy-n-propyltrimethoxysilane; the monoorganotrialkoxysilane is isobutyltrimethoxysilane, the Grignard reagent is isopropylmagnesium chloride and the product is isobutylisopropyldimethoxysilane; the monoorganotrialkoxysilane is isobutyltrimethoxysilane, the Grignard reagent is cyclopentylmagnesium chloride and the product is isobutylcyclopentyldimethoxysilane; the monoorganotrialkoxysilane is isobutyltrimethoxysilane, the Grignard reagent is cyclohexylmagnesium chloride and the product is isobutylcyclohexyldimethoxysilane; the monoorganotrialkoxysilane is n-octyltriethoxysilane, the Grignard reagent is sec-butylmagnesium chloride and the product is n-octyl-secbutyldiethoxysilane or the monoorganotrialkoxysilane is isopropyltripropoxysilane, the Grignard reagent is cyclopentylmagnesium chloride and the product is isopropylcyclopentyldipropoxysilane.

Claim 17

The method of claim 1 wherein the tetraalkoxysilane is tetramethoxysilane, the Grignard reagent is isopropylmagnesium chloride and the product is diisopropyldimethoxysilane; the tetraalkoxysilane is tetramethoxysilane, the Grignard reagent is cyclopentylmagnesium chloride and the product is dicyclopentyldimethoxysilane; the tetraalkoxysilane is tetramethoxysilane, the Grignard reagent is isoamylmagnesium chloride and the product is diisoamyldimethoxysilane; the tetraalkoxysilane is tetrapropoxysilane, the Grignard reagent is sec-butylmagnesium chloride and the product is di-sec-butyldipropoxysilane or the tetraalkoxysilane is tetrapentoxysilane, the Grignard reagent is sec-butylmagnesium chloride and the product is di-sec-butyldipentoxysilane.

Claim 18

In a process for preparing a diorganodialkoxysilane having the formula ##STR13## by reacting a tetraalkoxysilane of the formula Si(OR 3 ) 4 with an alkylating agent, the improvement comprises selecting as the alkylating agent a Grignard reagent having a secondary carbon atom, of the formula R 2 MgX wherein R 2 is ##STR14## R 4 is alkyl having 1 to 7 carbon atoms, R 5 is alkyl having 1 to 7 carbon atoms, or R 4 and R 5 taken together form a cycloalkyl group having 3 to 10 carbon atoms, each R 3 is the same or different and is alkyl having 1 to 5 carbon atoms, and X is Cl, Br and I, and y=0 or 1, reacting an alkylating-effective amount of said Grignard reagent with said tetraalkoxysilane and thereby forming a substantially pure diorganodialkoxysilane in quantitative yields.

Claim 19

In a process for preparing a diorganodialkoxysilane having the formula ##STR13## by reacting a tetraalkoxysilane of the formula Si(OR 3 ) 4 with an alkylating agent, the improvement comprises selecting as the alkylating agent a Grignard reagent having a secondary carbon atom, of the formula R 2 MgX wherein R 2 is ##STR14## R 4 is alkyl having 1 to 7 carbon atoms, R 5 is alkyl having 1 to 7 carbon atoms, or R 4 and R 5 taken together form a cycloalkyl group having 3 to 10 carbon atoms, each R 3 is the same or different and is alkyl having 1 to 5 carbon atoms, and X is Cl, Br and I, and y=0 or 1, reacting an alkylating-effective amount of said Grignard reagent with said tetraalkoxysilane and thereby forming a substantially pure diorganodialkoxysilane in quantitative yields.

Claim 20

The improved process of claim 17 wherein the yield is greater than 95% and purity greater than 97%.

Claim 21

The improved process according to claim 17 wherein the effective amount of Grignard reagent is present in a molar ratio of tetraalkoxysilane to Grignard reagent ranging from 1:2 to 1:10.

Claim 22

The improved process according to claim 19 wherein the molar ratio range from 1:2 to 1:5.

Claim 23

The improved process of claim 17, wherein the reaction is conducted in methyl-tert-butylether.

Claim 24

The improved process of claim 17 which comprises quenching any excess Grignard reagent remaining after reaction with a stoichiometric amount of an alcohol R 3 OH thereby forming a side product R 3 OMgX.

Claim 25

In a process for preparing a diorganodialkoxysilane having the formula ##STR15## by reacting an alkylating agent with a monoorganotrialkoxysilane, the improvement which comprises selecting a monoorganotrialkoxysilane having a secondary carbon atom or an alkylating agent having a secondary carbon atom, wherein the monoorganotrialkoxysilane has the formula R 1 Si(OR 3 ) 3 and the Grignard reagent has the formula R 2 MgX, and one of R 1 and R 2 is ##STR16## and the other is n-alkyl having 3 to 10 carbon atoms or is ##STR17## R 4 is alkyl having 1 to 7 carbon atoms, R 5 is alkyl having 1 to 7 carbon atoms, or R 4 and R 5 taken together with the carbon atom to which they are attached form a cycloalkyl group having 3 to 10 carbon atoms, each R 3 may be the same or different and is alkyl having 1 to 5 carbon atoms, X is Br, Cl or I, and y is 0 or 1, reacting at a temperature of about 0° to about 90° C. an alkylating-effective amount of said Grignard reagent with said monoorganotrialkoxysilane and thereby forming a substantially pure diorganodialkoxysilane in quantitative yields.

Claim 26

In a process for preparing a diorganodialkoxysilane having the formula ##STR15## by reacting an alkylating agent with a monoorganotrialkoxysilane, the improvement which comprises selecting a monoorganotrialkoxysilane having a secondary carbon atom or an alkylating agent having a secondary carbon atom, wherein the monoorganotrialkoxysilane has the formula R 1 Si(OR 3 ) 3 and the Grignard reagent has the formula R 2 MgX, and one of R 1 and R 2 is ##STR16## and the other is n-alkyl having 3 to 10 carbon atoms or is ##STR17## R 4 is alkyl having 1 to 7 carbon atoms, R 5 is alkyl having 1 to 7 carbon atoms, or R 4 and R 5 taken together with the carbon atom to which they are attached form a cycloalkyl group having 3 to 10 carbon atoms, each R 3 may be the same or different and is alkyl having 1 to 5 carbon atoms, X is Br, Cl or I, and y is 0 or 1, reacting at a temperature of about 0° to about 90° C. an alkylating-effective amount of said Grignard reagent with said monoorganotrialkoxysilane and thereby forming a substantially pure diorganodialkoxysilane in quantitative yields.

Claim 27

The improved process of claim 23 wherein the yield is greater than 95% and purity greater than 97%.

Claim 28

The improved process according to claim 23 wherein the effective amount of Grignard reagent is present in a molar ratio of monoorganotrialkoxysilane to Grignard reagent ranging from 1:1 to 1:10.

Claim 29

The improved process according to claim 25 wherein the molar ratio ranges from 1:1 to 1:3.

Claim 30

The improved process of claim 23, wherein the reaction is conducted in methyl-tert-butylether.

Claim 31

The improved process of claim 23 which comprises quenching any excess Grignard reagent remaining after reaction with a stoichiometric amount of an alcohol R 3 OH thereby forming a side product R 3 OMgX.