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US5420322A
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Preparation of alkali-metal hexamethydisilazanes
Assignee: BASF SE
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Filing: 1994-08-31
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Granted: 1995-05-30
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Expires: 2014-08-31
Abstract
Abstract A one-step synthesis of an alkali-metal hexamethyldisilazane is provided in which an alkali metal selected from the group consisting of lithium, sodium and potassium is reacted with 1,1,1,3,3,3,-hexamethyldisilazane at a reaction temperature above the melting point of the alkali metal without the use of an electron carrier, alkali-metal derivatized reagents, such as alkyl-aryl organometals, alkali-metal amides and alkali-metal hydrides, or a catalyst.
Inventors
- 👤 Kuen-Wai Chiu
- 👤 David H. Ellenberger
- 👤 Joseph M. Barendt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:16
CPC Classifications
C; C07; C07F; C07F7/00; C07F7/02; C07F7/08; C07F7/10
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
51 words
A method for a one-step synthesis of an alkali-metal hexamethyldisilazane comprising the step of reacting an alkali metal selected from the group consisting of lithium, sodium and potassium with 1,1,1,3,3,3,-hexamethyldisilazane at a reaction temperature greater that the melting point of the alkali metal without the use of an electron carrier reagent.
Claim 2
Independent Claim
51 words
A method for a one-step synthesis of an alkali-metal hexamethyldisilazane comprising the step of reacting an alkali metal selected from the group consisting of lithium, sodium and potassium with 1,1,1,3,3,3,-hexamethyldisilazane at a reaction temperature greater that the melting point of the alkali metal without the use of an electron carrier reagent.
Claim 3
Dependent Claim
21 words
The method of claim 1 wherein the alkali metal is lithium and the reaction temperature is at least approximately 190° C.
Claim 4
Dependent Claim
15 words
The method of claim 2 wherein the reaction temperature is at least approximately 225° C.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein the alkali metal is sodium and the reaction temperature is at least 190° C.
Claim 6
Dependent Claim
15 words
The method of claim 4 wherein the reaction temperature is at least approximately 225° C.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein the alkali metal is potassium and the reaction temperature is at least 100° C.
Claim 8
Dependent Claim
13 words
The method of claim 6 wherein the reaction takes place in a solvent.
Claim 9
Dependent Claim
18 words
The method of claim 7 wherein the solvent is selected from the group consisting of toluene and tetrahydrofuran.
Claim 10
Dependent Claim
21 words
The method of claim 8 wherein the solvent is tetrahydrofuran and the reaction temperature is no greater than approximately 140° C.
Claim 11
Dependent Claim
21 words
The method of claim 8 wherein the solvent is toluene and the reaction temperature is no greater than approximately 200° C.
Claim 12
Dependent Claim
13 words
The method of claim 3 wherein the reaction takes place in a solvent.
Claim 13
Dependent Claim
24 words
The method of claim 11 wherein the solvent is selected from the group consisting of hexylamine, 1,3-diaminopropane, butyl ether, toluene, xylene, cumene and 1,1,1,3,3,3,-hexamethyldisilazane.
Claim 14
Dependent Claim
13 words
The method of claim 5 wherein the reaction takes place in a solvent.
Claim 15
Dependent Claim
24 words
The method of claim 13 wherein the solvent is selected from the group consisting of hexylamine, 1,3-diaminopropane, butyl ether, toluene, xylene, cumene and 1,1,1,3,3,3,-hexamethyldisilazane.
Claim 16
Dependent Claim
26 words
The method of claim 1 wherein the reaction takes place in a solvent selected from the group consisting of an ether, a hydrocarbon and an amine.
Claim 17
Dependent Claim
27 words
The method of claim 15 wherein the solvent is selected from the group consisting of tetrahydrofuran, butyl ether, monoglyme, diglyme, triglyme, toluene, xylene, cumene and 1,1,1,3,3,3, -hexamethyldisilazane.
Claim 18
Dependent Claim
10 words
The method of claim 3 wherein excess 1,1,1,3,3,3,-hexamethyldisilazane is used.
Claim 19
Dependent Claim
10 words
The method of claim 5 wherein excess 1,1,1,3,3,3,-hexamethyldisilazane is used.
References Cited (Backward Citations)
US4659850A
Cited
US4882448A
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1998-05-29 | 1998-11-28 | 1999-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-05-29 | 2002-11-28 | 2003-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-05-29 | 2006-11-28 | 2007-05-30 | $7700.00 | Window Closed / Lapsed |