Patent US4957726A successfully refreshed from Google Patents.
US4957726A
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Preparation of amine alanes and lithium aluminum tetrahydride
Assignee: Albemarle Corp
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Filing: 1989-04-12
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Granted: 1990-09-18
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Expires: 2009-04-12
Abstract
Abstract Lithium aluminum hydride reacts with a tertiary amine to produce an amine alane and Li 3 AlH 6 . Lithium values are recycled by reacting Li 3 AlH 6 with aluminum and hydrogen to produce LiAlH 4 . Since no metal halide by-product is produced in the first step, it has an advantage over other routes. The amine alane can react with SiF 4 to produce silane and AlF 3 .
Inventors
- 👤 Everett M. Marlett
- 👤 Arcelio J. Malcolm
- 👤 Won S. Park
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:29
CPC Classifications
C; C01; C01B; C01B6/00; C01B6/24; C01B6/243; C01B6/06
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
50 words
A process which comprises, in combination: (a) reacting lithium aluminum tetrahydride and a tertiary amine such that an amine alane and lithium aluminum hexahydride are produced, and (b) reacting lithium aluminum hexahydride from the reaction of (a) with aluminum and hydrogen under pressure such that lithium aluminum tetrahydride is produced.
Claim 2
Dependent Claim
50 words
A process which comprises, in combination: (a) reacting lithium aluminum tetrahydride and a tertiary amine such that an amine alane and lithium aluminum hexahydride are produced, and (b) reacting lithium aluminum hexahydride from the reaction of (a) with aluminum and hydrogen under pressure such that lithium aluminum tetrahydride is produced.
Claim 3
Dependent Claim
30 words
A process of claim 1 wherein at least a portion of the lithium aluminum tetrahydride produced in the reaction of (b) is recycled for use in the reaction of (a).
Claim 4
Dependent Claim
25 words
A process of claim 1 wherein the reaction of (a) is conducted in a liquid reaction medium in which lithium aluminum hexahydride is substantially insoluble.
Claim 5
Dependent Claim
42 words
A process of claim 1 wherein the reaction of (a) is conducted in a liquid reaction medium, said medium being predominantly a mixture of one or more aromatic hydrocarbons or a mixture of one or more ethers or a mixture of both.
Claim 6
Dependent Claim
19 words
A process of claim 4 wherein said reaction medium is predominantly a mixture of one or more aromatic hydrocarbons.
Claim 7
Dependent Claim
12 words
A process of claim 4 wherein said reaction medium is predominantly toluene.
Claim 8
Dependent Claim
13 words
A process of claim 4 wherein said reaction medium is predominantly diethyl ether.
Claim 9
Dependent Claim
11 words
A process of claim 1 wherein the tertiary amine is trimethylamine.
Claim 10
Dependent Claim
11 words
A process of claim 1 wherein the tertiary amine is N,N-dimethylethylamine.
Claim 11
Dependent Claim
11 words
A process of claim 1 wherein the tertiary amine is N-methylpyrrolidine.
Claim 12
Dependent Claim
25 words
A process of claim 1 wherein the reaction of (b) is conducted in the presence of a reaction-promoting element from Group IV-B or Group V-B.
Claim 13
Dependent Claim
24 words
A process of claim 11 wherein said reaction promoter is metallic titanium introduced into the reaction of (b) as a titanium-containing alloy of aluminum.
Claim 14
Dependent Claim
18 words
A process of claim 1 wherein the reaction of (b) is conducted in the presence of a catalyst.
Claim 15
Dependent Claim
12 words
A process of claim 13 wherein said catalyst is an aluminum alkyl.
Claim 16
Dependent Claim
10 words
A process of claim 13 wherein said catalyst is trialkylaluminum.
Claim 17
Dependent Claim
10 words
A process of claim 13 wherein said catalyst is triethylaluminum.
Claim 18
Dependent Claim
24 words
A process of claim 1 wherein the reaction of (b) is conducted in a liquid reaction medium stable under the conditions of the reaction.
Claim 19
Dependent Claim
16 words
A process of claim 17 wherein the reaction medium comprises at least in part an ether.
Claim 20
Dependent Claim
14 words
A process of claim 17 wherein the reaction medium is predominantly a liquid tetrahydrofuran.
Claim 21
Dependent Claim
41 words
A process of claim 1 wherein the reactants of (b) are at a pressure in about the range of 2000 to 5000 psi and at about the temperature of 120° C. to 140° C., such that lithium aluminum tetrahydride is produced.
Claim 22
Dependent Claim
67 words
A process of claim 1 wherein the reaction of (b) is conducted in the presence of an amount of triethylaluminum sufficient to promote the reaction, in a liquid reaction medium which is predominantly tetrahydrofuran, at a pressure in about the range of 2000 to 5000 pounds per square inch and at about the temperature of 120 C to 140 C, such that lithium aluminum tetrahydride is produced.
Claim 23
Dependent Claim
85 words
A process which comprises, in combination: (a) reacting lithium aluminum tetrahydride and a tertiary amine in a liquid aromatic hydrocarbon reaction medium such that an amine alane and lithium aluminum hexahydride are produced, (b) reacting lithium aluminum hexahydride from the reaction of (a) with aluminum and hydrogen under pressure in a liquid ether reaction medium such that lithium aluminum tetrhydride is produced, and (c) recycling to the reaction of (a) at least a portion of the lithium aluminum tetrahydride produced in the reaction of (b).
Claim 24
Dependent Claim
85 words
A process which comprises, in combination: (a) reacting lithium aluminum tetrahydride and a tertiary amine in a liquid aromatic hydrocarbon reaction medium such that an amine alane and lithium aluminum hexahydride are produced, (b) reacting lithium aluminum hexahydride from the reaction of (a) with aluminum and hydrogen under pressure in a liquid ether reaction medium such that lithium aluminum tetrhydride is produced, and (c) recycling to the reaction of (a) at least a portion of the lithium aluminum tetrahydride produced in the reaction of (b).
Claim 25
Dependent Claim
93 words
A process of claim 22 wherein (1) the reaction of (a) is conducted in a liquid reaction medium which is predominantly a mononuclear aromatic hydrocarbon, and (2) the reaction of (b) is conducted in a liquid reaction medium which is predominantly a saturated cyclic ether, in the presence of an amount of an aluminum alkyl sufficient to promote the reaction, at a pressure in about the range of 2000 to 5000 pounds per square inch and at about the temperature of 120° C. to 140° C., such that lithium aluminum tetrahydride is produced.
Claim 26
Dependent Claim
22 words
A process of claim 23 wherein the aromatic hydrocarbon is toluene, the cyclic ether is tetrahydrofuran, and the aluminum alkyl is triethylaluminum.
Claim 27
Dependent Claim
21 words
A process of claim 23 wherein the aluminum employed in the reaction of (b) contains a minor reaction-promoting amount of titanium.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-09-17 | 1994-03-19 | 1994-09-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-17 | 1998-03-19 | 1998-09-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-17 | 2002-03-19 | 2002-09-18 | $7700.00 | Window Closed / Lapsed |