# US 2021/0277033 A1 · Method for preparing hydrocarbylhydrocarbyloxysilanes

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- Number: US 2021/0277033 A1
- Document ID: US20210277033A1
- Status: Published application
- Kind: A1
- Application number: 17/261,594
- Filed: 2019-08-21
- Published: 2021-09-09
- Earliest claimed: 2018-09-07
- Assignees: Dow Silicones Corporation
- Applicants: Dow Silicones Corporation
- Inventors: Dimitris Katsoulis; John Roberts
- Web page: https://patentgrep.com/patent/US20210277033A1

## CPC

- C07F 7/188: {by reactions involving the formation of Si-O linkages}
- B01J 21/06: Silicon, titanium, zirconium or hafnium; Oxides or hydroxides thereof
- B01J 23/72: Copper
- C01B 33/06: Metal silicides (alloys C22)
- C07F 7/1876: {by reactions involving the formation of Si-C linkages}
- C07F: ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM (metal-containing porphyrins C07D487/22)
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C}

## Abstract

A method for preparing a hydrocarbylhydrocarbyloxysilane of formula RaHpSi(OR)(4-a-b), where each R is independently a hydrocarbyl group and subscript a is 1 to 4 and subscript b is 1 to 2 is disclosed. The method includes heating ingredients including a hydrocarbyl carbonate and a source of silicon and catalyst. The method can be used to make dimethyldimethoxysilane.

## Claims

### Claim 1

A method comprises:
1) heating at a temperature of 150° C. to 400° C., ingredients comprising
a) a hydrocarbyl carbonate, and
b) a source of silicon and catalyst, where starting material b) is selected from the group consisting of copper silicide and a contact mass used in the Mueller-Rochow Direct Process, which comprises silicon metal and a catalyst such as copper;
thereby forming a reaction product comprising an hydrocarbylhydrocarbyloxysilane of formula RaHbSi(OR)(4-a-b), where each R is independently a hydrocarbyl group and subscript a is 1 to 4 and subscript b is 0 to 2.

### Claim 2 (depends on 1)

The method of claim 1, where the hydrocarbyl carbonate is selected from dimethyl carbonate, diethyl carbonate, diphenyl carbonate, or methyl phenyl carbonate.

### Claim 3 (depends on 1)

The method of claim 1, where the catalyst comprises copper.

### Claim 4 (depends on 1)

The method of claim 1, where ingredient b) is a copper silicide.

### Claim 5 (depends on 4)

The method of claim 4, where the copper silicide is a binary copper silicide.

### Claim 6 (depends on 4)

The method of claim 4, where the copper silicide is Cu5Si.

### Claim 7 (depends on 4)

The method of claim 4, where the copper silicide comprises copper, silicon and an additional metal selected from the group consisting of aluminium, tin, titanium, and combinations of two or more of aluminium, tin, and titanium.

### Claim 8 (depends on 1)

The method of claim 1, where ingredient b) comprises a contact mass comprising silicon and copper.

### Claim 9 (depends on 8)

The method of claim 8, further comprising adding d) a promoter.

### Claim 10 (depends on 9)

The method of claim 9, where the promoter comprises aluminium, tin, titanium, or a combination of two or more of aluminium, tin, and titanium.

### Claim 11 (depends on 1)

The method of claim 1, further comprising adding c) hydrogen during step 1).

### Claim 12 (depends on 1)

The method of claim 1, where each R is methyl, ethyl or phenyl.

### Claim 13 (depends on 1)

The method of claim 1, where the hydrocarbylhydrocarbyloxysilane comprises methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, and tetramethoxysilane.

### Claim 14 (depends on 1)

The method of claim 1, where the reaction product comprises a hydrocarbylhydrocarbyloxysilane of formula R2Si(OR)2.

### Claim 15 (depends on 1)

The method of claim 1, further comprising purging and/or treating ingredient b) before step 1) and/or 2) recovering the hydrocarbylhydrocarbyloxysilane from the reaction product.

### Claim 16 (depends on 2)

The method of claim 2, where ingredient b) is a copper silicide.

### Claim 17 (depends on 2)

The method of claim 2, where ingredient b) comprises a contact mass comprising silicon and copper.