Method for the dehydrogenation of dichlorosilane

Patent metadata

Field	Value
Publication number	US-12060375-B2
Application number	US-201817272904-A
Country	US
Kind code	B2
Filing date	Sep 6, 2018
Priority date	Sep 6, 2018
Publication date	Aug 13, 2024
Grant date	Aug 13, 2024

Abstract

Dichlorosilane and trichlorosilane are dehydrogenated at elevated temperature in the presence of an ammonium or phosphonium salt as a catalyst, and a halogenated hydrocarbon or hydrogen halide. The method may be used to synthesize organochlorosilane.

First claim

The invention claimed is:

1. A method for the dehydrogenation of dichlorosilane in which hydrogen is formed, comprising:
dehydrogenating dichlorosilane in the presence of an ammonium and/or phosphonium salt catalyst at a temperature within a range of 70-300° C., by reacting with either
(A) at least one halogenated hydrocarbon of the formula (I)

where
X is F, Cl, Br or I; and
R 1 is a branched or unbranched C 2 -C 20 alkyl radical,
a branched or unbranched C 2 -C 13 heteroalkyl radical, the carbon skeleton of which contains one or more heteroatoms independently selected from N, P, S or O,
a branched or unbranched C 1 -C 10 fluoroalkyl radical with partial or complete fluorination,
a branched or unbranched C 2 -C 20 alkenyl radical, excluding C 2 H 4-n Cl n radicals where
n is 2-4,
a branched or unbranched C 2 -C 20 alkynyl radical,
a C 3 -C 14 cycloalkyl radical,
a C 2 -C 13 heterocycloalkyl radical, the ring skeleton of which contains one or more heteroatoms independently selected from N, P, S or O,
a C 6 -C 14 aryl radical,
a C 5 -C 13 heteroaryl radical, the ring skeleton of which contains one or more heteroatoms independently selected from N, P, S or O, and/or
(CH 2 ) n -Ar, where Ar is a C 6 -C 14 aryl radical and n is 1-5,
where all of the above-mentioned radicals may be unsubstituted or else singly or multiply substituted by halogen, C 1 -C 4 alkoxy, vinyl, phenyl or C 1 -C 4 alkyl,
radicals,
(CH 2 ) n X, where n is 1-10 and X is F, Cl, Br or I,
R 2 —S—CH 2 radicals, where R 2 is C 1 -C 6 alkyl or C 6 -C 14 aryl,
(CH 2 ) n SiMe 3-m -Cl m , where n is 0-5 and m is 0, 1, 2, 3,
(CH 2 ) n NH(C═O)OCH 3 , where n is 1-5,
(CH 2 ) n OCH 2 (oxirane), where n is 1-5,
(CH 2 )O(C═O)(C(CH 3 )═CH 2 ), where n is 1-5,
(CH 2 ) n NH 2 , where n is 1-5,
(CH 2 ) n NH(C═O)NH 2 , where n is 1-5, and
(CH 2 ) n NHR, where n=1-5, and R is cyclohexyl or C 2 H 4 NH 2 ;

or with
(B) a hydrogen halide,

wherein the molar ratio of dichlorosilane to hydrogen halide or halogenated hydrocarbon is within a range from 1:1 to 1:10.

2. The method of claim 1 , wherein the temperature is within the range of 100-300° C.

3. The method of claim 1 , wherein the molar ratio of catalyst to dichlorosilane is within the range from 0.01:1 to 0.2:1.

4. The method of claim 1 , wherein a hydrogen halide is present, and the hydrogen halide is hydrogen chloride.

5. The method of claim 1 , wherein the ammonium and/or phosphonium salt is a quaternary ammonium halide [R 4 N]X, a phosphonium halide [R 4 P]X, or a tertiary ammonium halide [R 3 NH]X, where X is Cl, Br or I.

6. The method of claim 5 , wherein the ammonium and/or phosphonium salt is selected from the group consisting of [n-Bu 4 N]Cl, [Et 4 N]Cl, [Ph 4 P]Cl, [n-Bu 4 P]Cl, and mixtures thereof.

7. The method of claim 1 , wherein R 1 is selected from the group consisting of branched or unbranched C 2 -C 20 alkyl radicals,
a branched or unbranched C 2 -C 13 heteroalkyl radical, the carbon skeleton of which contains one or more heteroatoms independently selected from N, P, S or O;
a branched or unbranched C 2 -C 20 alkenyl radical, excluding C 2 H 4-n Cl n when n is 2-4,
a C 3 -C 14 cycloalkyl radical,
a C 2 -C 13 heterocycloalkyl radical, the ring skeleton of which contains one or more heteroatoms independently selected from N, P, S or O, and
(CH 2 ) n -Ar, where Ar is a C 6 -C 14 aryl radical and n is 1-3,
where all of the above-mentioned radicals may be unsubstituted or else singly or multiply substituted by halogen, C 1 -C 4 alkoxy, vinyl, phenyl or C 1 -C 4 alkyl,
(CH 2 ) n X, where n is 1-10 and X is F, Cl, Br or I,
(CH 2 ) n SiMe 3-m -Cl m , where n is 0-5 and m is 0, 1, 2, 3.

8. The method of claim 1 , wherein the halogenated hydrocarbon is selected from the group consisting of methyl chloride, ethyl chloride, n-propyl chloride, isopropyl chloride, n-butyl chloride, tert-butyl chloride, isobutyl chloride, sec-butyl chloride, n-pentyl chloride, n-pentyl iodide, n-pentyl bromide, n-pentyl fluoride, n-octyl chloride, 1-chlorohexadecane, 1,2-dichloroethane, 1,1-dichloropropane, 1,2-dichloropropane, 1,3-dichloropropane, monochlorobenzene, benzyl chloride, vinyl chloride, allyl chloride, allyl bromide, 1-chloro-2,4,4-trimethylpentane, hexadecyl chloride, 1-chloro-3,3,3-trifluoropropane, trichloro(chloromethyl)silane, dichloro(chloromethyl)silane, trimethyl(chloromethyl)silane, trimethyl(3-chloropropyl)silane, crotyl chloride, 4-fluorobenzyl chloride, 4-chlorobenzyl chloride, 4-methoxybenzyl chloride, 4-phenylbenzyl chloride, diphenyl-1-dichloromethane, (1-chloroethyl)benzene, cyclopentyl chloride, 1-bromo-3-chloropropane, 1,4-dichlorobutane, 1,4-bis(chloromethyl)benzene, and mixtures thereof.

9. The method of claim 1 , wherein dichlorosilane is formed in situ by disproportionation of trichlorosilane.

10. The method of claim 1 , wherein the method is operated continuously or batchwise.

11. The process of claim 1 , wherein the amount of halogenated hydrocarbon present is a stoichiometric excess relative to dichlorosilane, up to a mol ratio of 10:1.

12. The method of claim 1 , wherein dichlorosilane is reacted with hydrogen halide to form a dichlorohalosilane with formation of hydrogen.

13. The method of claim 12 , wherein the hydrogen halide is hydrogen chloride, and the products are trichlorosilane and hydrogen.

14. The method of claim 1 , wherein the catalyst is an ammonium salt.

Assignees

• Wacker Chemie Ag

Inventors

• Tillmann Jan
• Weidner Richard

Classifications

• C01B3/06

  by reaction of inorganic compounds containing electro-positively bound hydrogen with inorganic reducing agents · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title

• C07F7/125 Primary

  by reactions involving both Si-C and Si-halogen linkages, the Si-C and Si-halogen linkages can be to the same or to different Si atoms, e.g. redistribution reactions · CPC title