US4173578A
Expired / Lapsed
US
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Production of alkenyl phosphinic acids
Assignee: Hoechst AG
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Filing: 1977-10-11
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Granted: 1979-11-06
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Expires: 1997-10-11
Abstract
Abstract Production of alkenyl phosphinic acids of the general formula: ##STR1## in which R 1 stands for an alkyl, aralkyl, cycloalkyl or aryl group having 1 to 20 carbon atoms, and R 2 stands for hydrogen or an alkyl group having 1 to 4 carbon atoms. The compounds are made by subjecting a 2-halogenoalkyl phosphinic acid-2-halogenoalkyl ester of the general formula: ##STR2## in which R 1 and R 2 have the meanings given above, and X stands for a halogen atom, to thermal decomposition.
Inventors
- 👤 Horst Staendeke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:49
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/30; C07F9/302
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
103 words
A process for making alkenyl phosphinic acids of the general formula ##STR7## in which R 1 stands for an alkyl, aralkyl, cycloalkyl or aryl group having 1 to 20 carbon atoms, and R 2 stands for hydrogen or an alkyl group having 1 to 4 carbon atoms, which comprises subjecting a 2-halogenoalkyl phosphinic acid-2-halogenoalkyl ester of the general formula ##STR8## in which R 1 and R 2 have the meanings given above, and X stands for a halogen atom, to thermal decomposition by heating in a stream of inert gas at temperatures of 150° to 300° C. and simultaneously separating the resulting 1,2-dihalogenoalkane.
Claim 2
Dependent Claim
103 words
A process for making alkenyl phosphinic acids of the general formula ##STR7## in which R 1 stands for an alkyl, aralkyl, cycloalkyl or aryl group having 1 to 20 carbon atoms, and R 2 stands for hydrogen or an alkyl group having 1 to 4 carbon atoms, which comprises subjecting a 2-halogenoalkyl phosphinic acid-2-halogenoalkyl ester of the general formula ##STR8## in which R 1 and R 2 have the meanings given above, and X stands for a halogen atom, to thermal decomposition by heating in a stream of inert gas at temperatures of 150° to 300° C. and simultaneously separating the resulting 1,2-dihalogenoalkane.
Claim 3
Dependent Claim
19 words
The process as claimed in claim 1, wherein the 1,2-dihalogenoalkane is separated by distillation, if desired, under reduced pressure.
Claim 4
Dependent Claim
31 words
The process as claimed in claim 1, wherein the 2-halogenoalkyl phosphinic acid-2-halogenoalkyl ester is selected from those compounds of formula II, in which X stands for a chlorine or bromine atom.
Claim 5
Dependent Claim
36 words
The process as claimed in claim 3, wherein the methyl-2-chloroethyl phosphinic acid-2-chloroethyl ester; ethyl-2-chloroethyl phosphinic acid-2-chloroethyl ester; phenyl-2-chloroethyl phosphinic acid-2-chloroethyl ester; methyl-2-chloropropyl phosphinic acid-2-chloropropyl ester; ethyl-2-chloropropyl phosphinic acid-2-chloropropyl ester or phenyl-2-chloropropyl phosphinic acid-2-chloropropyl ester is used.
Claim 6
Dependent Claim
32 words
The process as claimed in claim 1, wherein the starting materials are initially heated until 1,2-dihalogenoalkane ceases to be evolved, and the heating is repeated, after the introduction of a hydrogen halide.
Claim 7
Dependent Claim
24 words
The process as claimed in claim 5, wherein 0.2 to 3 mols of hydrogen halide is used per mol of 2-halogenoalkyl phosphinic acid-2-halogenoalkyl ester.
References Cited (Backward Citations)
US3787486A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |