US4448942A
Expired / Lapsed
US
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Process for the production of hydantoins
Assignee: Bayer AG
•
Filing: 1982-11-01
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Granted: 1984-05-15
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Expires: 2002-11-01
Abstract
Abstract The invention relates to a new process for the production of compounds containing at least one hydantoin ring by reacting a carbodiimide with a derivative of an α,β-unsaturated carboxylic acid corresponding to the following general formula: ##STR1## wherein R 3 , R 4 and R 5 are as defined in the description.
Inventors
- 👤 Bernhard Schulte
- 👤 Wolfgang Jakob
- 👤 Willi Dunwald
- 👤 Karl-Heinrichrich Meyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 18:25
CPC Classifications
C; C07; C07D; C07D233/00; C07D233/54; C07D233/66; C07D233/72; C07D233/76; C07D233/78; C08; C08G; C08G73/00; C08G73/06; C08G73/0605; C08G73/0616; C08G73/10; Y; Y10; Y10S; Y10S525/00; Y10S525/907
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
79 words
A process for the production of a compound having at least one hydantoin ring, wherein a polyimide is reacted with an acid corresponding to the formula ##STR11## wherein R 3 and R 4 represent hydrogen or an alkyl radical; R 5 represents a CN-- group, a CHO-- group, COOR 6 -- group or ##STR12## in which R 6 , R 7 and R 8 represent alkyl, cycloalkyl, alkenyl or alkinyl; at temperatures of from about -20° to 250° C.
Claim 2
Dependent Claim
79 words
A process for the production of a compound having at least one hydantoin ring, wherein a polyimide is reacted with an acid corresponding to the formula ##STR11## wherein R 3 and R 4 represent hydrogen or an alkyl radical; R 5 represents a CN-- group, a CHO-- group, COOR 6 -- group or ##STR12## in which R 6 , R 7 and R 8 represent alkyl, cycloalkyl, alkenyl or alkinyl; at temperatures of from about -20° to 250° C.
Claim 3
Dependent Claim
18 words
A process according to claim 1 wherein the reaction preceeds in contact with a solvent and a catalyst.
Claim 4
Dependent Claim
18 words
A process according to claim 2 wherein the solvent is methylenechloride or a mixture of solvents containing methylenechloride.
Claim 5
Dependent Claim
15 words
A process according to claim 1 wherein the polyimide is a linear or branched polycarbodiimide.
Claim 6
Dependent Claim
87 words
A process as claimed in claim 1 wherein said polyimide is of the formula --Y--N═C═N--.sub.n wherein Y represents at least one aliphatic radical containing 2 to 12 carbon atoms, cycloaliphatic radical containing from 5 to 12 carbon atoms or C 6 -C 16 aryl radical or diphenyl radical attached through O, S, SO 2 , CH 2 , CH 3 --C--CH 3 or CO or --Si(R 6 ) 2 -- or Sn(R 6 ) 2 -- group; and n represents an integer of from 2 to 2000.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-05-15 | 1987-11-14 | 1988-05-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-05-15 | 1991-11-14 | 1992-05-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-05-15 | 1995-11-14 | 1996-05-15 | $7700.00 | Window Closed / Lapsed |