US4239891A
Expired / Lapsed
US
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Substituted piperidine hydroxamides, their preparation, and their use as light stabilizers
Assignee: Hoechst AG
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Filing: 1978-09-18
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Granted: 1980-12-16
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Expires: 1998-09-18
Abstract
Abstract The invention provides novel derivatives of 2,2-dimethyl-6,6-dialkyl-4-hydroxy-4'-carbamoyl-piperidines which carry a substituent at the amide nitrogen atom, and optionally a further substituent at the ring nitrogen atom, and a process for preparing these compounds. The products, optionally in the form of salts, are used for stabilizing thermoplastics against the damaging influence of light.
Inventors
- 👤 Hartmut Wiezer
- 👤 Gerhard Pfahler
- 👤 Norbert Mayer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:01
CPC Classifications
C; C07; C07D; C07D211/00; C07D211/04; C07D211/06; C07D211/36; C07D211/60; C07D211/62; C07D211/66; C08; C08K; C08K5/00; C08K5/16; C08K5/34; C08K5/3412; C08K5/3432; C08K5/3435
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
94 words
A process for the preparation of piperidine hydroxyamides of the formula ##STR4## in which R 1 and R 2 are methyl; R 3 is tertiary alkyl of 4-8 carbons; and R 4 is hydrogen or alkyl of 1-4 carbons, which comprises reacting 2,2,6,6-tetramethyl-4-hydroxy-4-cyanopiperidine in an organic solvent with a tertiary alcohol of 4 to 8 carbons or an olefin of the same number of carbons, with addition of sulfuric acid as catalyst, in which process when an olefin is used at least an equimolar amount of water is added after the reaction is complete.
Claim 2
Dependent Claim
94 words
A process for the preparation of piperidine hydroxyamides of the formula ##STR4## in which R 1 and R 2 are methyl; R 3 is tertiary alkyl of 4-8 carbons; and R 4 is hydrogen or alkyl of 1-4 carbons, which comprises reacting 2,2,6,6-tetramethyl-4-hydroxy-4-cyanopiperidine in an organic solvent with a tertiary alcohol of 4 to 8 carbons or an olefin of the same number of carbons, with addition of sulfuric acid as catalyst, in which process when an olefin is used at least an equimolar amount of water is added after the reaction is complete.
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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) | 1983-12-16 | 1984-06-16 | 1984-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-16 | 1988-06-16 | 1988-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-16 | 1992-06-16 | 1992-12-16 | $7700.00 | Window Closed / Lapsed |