US4060541A
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Aromatic cyanic acid esters
Assignee: Bayer AG
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Filing: 1976-02-05
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Granted: 1977-11-29
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Expires: 1996-02-05
Abstract
Abstract Aromatic cyanic acid esters having a free hydroxyl group which is not sterically hindered are prepared by reacting aromatic dihydroxy and polyhydroxy compounds with cyanogen halide in aqueous solution in the presence of a water-immiscible organic solvent and an inorganic base. Aromatic cyanic acid esters prepared by the process have the formula ##STR1## wherein Ar is optionally substituted aromatic and n and m are the same or different and are one of the numbers from 1 to 5, with the sum m and n being not greater than the number of replaceable hydrogen atoms in the radical Ar.
Inventors
- 👤 Rudolf Sundermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 21:12
CPC Classifications
C; C07; C07C; C07C261/00; C07C261/02; C07C2601/00; C07C2601/12; C07C2601/14
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
85 words
Aromatic cyanic acid esters of the formula ##STR13## wherein R 3 , R 4 , R 5 and R 6 are the same or different and are hydrogen, halogen or alkyl, A is a bond between the aromatic rings or divalent alkyl with up to 6 carbon atoms, optionally substituted by lower alkyl, optionally substituted 5-membered or 6-membered cycloaliphatic, sulphonyl (--SO 2 --) or carbonyl (--CO--), wherein s and t are the same or different and are one of the numbers from 1 to 5.
Claim 2
Dependent Claim
85 words
Aromatic cyanic acid esters of the formula ##STR13## wherein R 3 , R 4 , R 5 and R 6 are the same or different and are hydrogen, halogen or alkyl, A is a bond between the aromatic rings or divalent alkyl with up to 6 carbon atoms, optionally substituted by lower alkyl, optionally substituted 5-membered or 6-membered cycloaliphatic, sulphonyl (--SO 2 --) or carbonyl (--CO--), wherein s and t are the same or different and are one of the numbers from 1 to 5.
Claim 3
Dependent Claim
65 words
Cyanic acid esters of the formula ##STR14## wherein Ar is optionally substituted aromatic and n and m are the same or different and are one of the numbers from 1 to 5, with the sum m and n being not greater than the number of replaceable hydrogen atoms in the radical Ar, said ester being from the group of 4-(4-Hydroxyphenylisopropyl)-phenyl cyanate, 2-(3,5-Dimethyl-4-hydroxyphenyl)-2-(3,5-dimethyl-4-cyanatophenyl)-propane, 2-(3,5-Dichloro-4-hydroxyphenyl)-2-(3,5-dichloro-4-cyanatophenyl)-propane, and 1-(4-Hydroxyphenyl)-1-(4-cyanatophenyl)-cyclohexane.
Claim 4
Dependent Claim
65 words
Cyanic acid esters of the formula ##STR14## wherein Ar is optionally substituted aromatic and n and m are the same or different and are one of the numbers from 1 to 5, with the sum m and n being not greater than the number of replaceable hydrogen atoms in the radical Ar, said ester being from the group of 4-(4-Hydroxyphenylisopropyl)-phenyl cyanate, 2-(3,5-Dimethyl-4-hydroxyphenyl)-2-(3,5-dimethyl-4-cyanatophenyl)-propane, 2-(3,5-Dichloro-4-hydroxyphenyl)-2-(3,5-dichloro-4-cyanatophenyl)-propane, and 1-(4-Hydroxyphenyl)-1-(4-cyanatophenyl)-cyclohexane.
Claim 5
Dependent Claim
93 words
Aromatic cyanic acid esters of the formula ##STR15## wherein R 1 and R 2 are the same or different and are alkyl or halogen and o and p are identical or different and represent one of the numbers from 1 to 5 and q and r are identical or different and represent one of the numbers 0, 1 or 2 with the sum of the numbers o, p, q and r being a maximum of 6 selected from the group consisting of m-hydroxyphenyl cyanate, p-hydroxyphenyl cyanate, 4,6-dimethyl-3-hydroxyphenyl cyanate, 2,3,5,6-tetramethyl-4-hydroxyphenyl cyanate and 5-methyl-3-hydroxyphenyl cyanate.
Claim 6
Dependent Claim
93 words
Aromatic cyanic acid esters of the formula ##STR15## wherein R 1 and R 2 are the same or different and are alkyl or halogen and o and p are identical or different and represent one of the numbers from 1 to 5 and q and r are identical or different and represent one of the numbers 0, 1 or 2 with the sum of the numbers o, p, q and r being a maximum of 6 selected from the group consisting of m-hydroxyphenyl cyanate, p-hydroxyphenyl cyanate, 4,6-dimethyl-3-hydroxyphenyl cyanate, 2,3,5,6-tetramethyl-4-hydroxyphenyl cyanate and 5-methyl-3-hydroxyphenyl cyanate.
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) | 1980-11-28 | 1981-05-30 | 1981-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-28 | 1985-05-30 | 1985-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-28 | 1989-05-30 | 1989-11-29 | $7700.00 | Window Closed / Lapsed |