US4676962A
Expired / Lapsed
US
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Preparation of B-trichloroborazine
Assignee: United States, NASA THE, Administrator of
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Filing: 1986-08-28
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Granted: 1987-06-30
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Expires: 2006-08-28
Abstract
Abstract The present invention relates to a method of preparing B-trichloroborazine, B 3 N 3 Cl 3 H 3 . Generally, the method includes the combination of gaseous boron trichloride in an anhydrous aprotic organic solvent followed by addition of excess gaseous ammonia at ambient temperature or below. The reaction mixture is heated to between about 100° to 140° C. followed by cooling, removal of the solid ammonium chloride at ambient temperature, distillation of the solvent under vacuum if necessary at a temperature of up to about 112° C., and recovery of the B-trichloroborazine. Solvents include, toluene, benzene, xylene, chlorinated hydrocarbons, chlorinated aromatic compounds, or mixtures thereof. Toluene is a preferred solvent. The process provides a convenient synthesis of a material which often decomposes on standing. B-trichloroborazine is useful in a number of chemical reactions, and particularly in the formation of high temperature inorganic polymers and polymer precursors.
Inventors
- 👤 Salvatore R. Riccitiello
- 👤 Ming-Ta S. Hsu
- 👤 Timothy S. Chen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:51
CPC Classifications
C; C01; C01B; C01B35/00; C01B35/08; C01B35/14; C01B35/146
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
122 words
A process for the preparation of B-trichloroborazine of the formula: ##STR3## which process comprises: (a) combining one equivalent of boron trichloride with at least two equivalents of ammonia at 0° C. or below in a solvent selected from chlorinated hydrocarbon compounds, aromatic compounds or mixtures thereof, wherein said solvent has a boiling point at ambient pressure of between about 100° C. to 140° C.; (b) heating the mixture of step (a) to between about 105° C. to 112° C. for a time sufficient to evolve the hydrogen chloride produced; (c) cooling the mixture of step (b) to about ambient temperature and separating the precipitate of ammonium chloride; (d) removing the solvent or solvent mixture of step (c); and (e) recovering the B-trichloroborazine.
Claim 2
Dependent Claim
122 words
A process for the preparation of B-trichloroborazine of the formula: ##STR3## which process comprises: (a) combining one equivalent of boron trichloride with at least two equivalents of ammonia at 0° C. or below in a solvent selected from chlorinated hydrocarbon compounds, aromatic compounds or mixtures thereof, wherein said solvent has a boiling point at ambient pressure of between about 100° C. to 140° C.; (b) heating the mixture of step (a) to between about 105° C. to 112° C. for a time sufficient to evolve the hydrogen chloride produced; (c) cooling the mixture of step (b) to about ambient temperature and separating the precipitate of ammonium chloride; (d) removing the solvent or solvent mixture of step (c); and (e) recovering the B-trichloroborazine.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein in step (a) between about three and six equivalents of ammonia are combined.
Claim 4
Dependent Claim
14 words
The process of claim 2 wherein the solvent is a mixture of aromatic compounds.
Claim 5
Dependent Claim
12 words
The process of claim 2 wherein the solvent aromatic compound is toluene.
Claim 6
Dependent Claim
15 words
The process of claim 4 wherein in step (c) the precipitate is separated by filtration.
Claim 7
Dependent Claim
22 words
The process of claim 5 wherein in step (b) the time to evolve hydrogen chloride is between about 1 to 6 hr.
Claim 8
Dependent Claim
18 words
The process of claim 6 wherein in step (d) the solvent or solvent mixture is removed by distillation.
Claim 9
Dependent Claim
22 words
The process of claim 7 wherein the distillation proceeds at between about 110° C. and 112° C. at ambient pressure or below.
Claim 10
Dependent Claim
106 words
A process for the preparation of B-trichloroborazine of the formula: ##STR4## which process comprises: (a) contacting gaseous boron trichloride with an aprotic, polar organic solvent at ambient temperature or below; (b) treating the solution of step (a) with at least two equivalents of gaseous ammonia at ambient temperature or below; (c) heating the solution of step (b) to between about 105° C. to 112° C. for a time sufficient to evolve hydrogen chloride; (d) cooling the mixture to step (c) to about ambient temperature and separating the precipitate of ammonium chloride from the solvent; (e) removing the solvent of step (d); and (f) recovering the B-trichloroborazine.
Claim 11
Dependent Claim
106 words
A process for the preparation of B-trichloroborazine of the formula: ##STR4## which process comprises: (a) contacting gaseous boron trichloride with an aprotic, polar organic solvent at ambient temperature or below; (b) treating the solution of step (a) with at least two equivalents of gaseous ammonia at ambient temperature or below; (c) heating the solution of step (b) to between about 105° C. to 112° C. for a time sufficient to evolve hydrogen chloride; (d) cooling the mixture to step (c) to about ambient temperature and separating the precipitate of ammonium chloride from the solvent; (e) removing the solvent of step (d); and (f) recovering the B-trichloroborazine.
Claim 12
Dependent Claim
13 words
The process of claim 9 wherein the solvent in step (a) is toluene.
Claim 13
Dependent Claim
19 words
The process of claim 10 wherein the temperature in step (c) is between about 110° C. and 112° C.
Claim 14
Dependent Claim
15 words
The process of claim 11 wherein in step (c) the time is about 240 minutes.
Claim 15
Dependent Claim
20 words
The process of claim 9 wherein in step (c) the ratio of product to solvent is about 1 to 20.
Claim 16
Dependent Claim
17 words
The process of claim 9 wherein in steps (a) and (b) the temperature is below 0° C.
Claim 17
Dependent Claim
37 words
The process of claim 9 wherein in step (a) the solvent is selected from chlorinated hydrocarbons, chlorinated aromatic compounds, aromatic compounds, or mixtures thereof, having a boiling point between 105° C. and 140° C. at ambient pressure.
Claim 18
Dependent Claim
15 words
The process of claim 15 wherein the solvent is selected from toluene, xylene, or chlorobenzene.
Claim 19
Dependent Claim
16 words
The process of claim 16 wherein in step (d) the ammonium chloride is separated by filtration.
Claim 20
Dependent Claim
10 words
The process of claim 17 wherein the solvent is xylene.
Claim 21
Dependent Claim
10 words
The process of claim 17 wherein the solvent is chlorobenzene.
References Cited (Backward Citations)
US2754177A
Cited
US4578283A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-29 | 1990-12-29 | 1991-06-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-29 | 1994-12-29 | 1995-06-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-29 | 1998-12-29 | 1999-06-30 | $7700.00 | Window Closed / Lapsed |