Patent US4052433A successfully refreshed from Google Patents.
US4052433A
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Aromatic azomethines
Assignee: Hoechst AG
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Filing: 1976-09-09
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Granted: 1977-10-04
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Expires: 1996-09-09
Abstract
Abstract Novel azomethines are obtained when reacting a tertiary amine with an aromatic aldehyde or ketone having in orthoposition an activated methoxy group. These azomethines are capable of ring closure to yield a benzofurane and said tertiary amine. The benzofuranes are optical brighteners, tranquilizers or intermediates for optical brighteners, fluorescent dyestuffs, scintillators, sensibilizers for electrophotographic coatings.
Inventors
- 👤 Wilfried Sahm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:03
CPC Classifications
C; C07; C07D; C07D307/00; C07D307/77
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
105 words
A compound of the formula ##STR62## in which A is phenyl or naphthyl which is unsubstituted or substituted by halogen, lower alkyl, lower alkoxy, lower alkylene forming an annellated ring, or phenyl, R is hydrogen, lower alkyl or phenyl, E is lower tertiary alkyl, phenyl, chlorophenyl, lower alkyl phenyl, lower hydroxyalkyl phenyl or naphthyl and D' is phenyl, naphthyl, styryl, or a bivalent group selected from ethenylene, phenylene and p,ω-styrylene which bivalent group is substituted by a group of the formula ##STR63## in which A, R and E are as defined above, which radical D' may be substituted by carboxy, lower carboalkoxy, cyano, or nitro.
Claim 2
Dependent Claim
105 words
A compound of the formula ##STR62## in which A is phenyl or naphthyl which is unsubstituted or substituted by halogen, lower alkyl, lower alkoxy, lower alkylene forming an annellated ring, or phenyl, R is hydrogen, lower alkyl or phenyl, E is lower tertiary alkyl, phenyl, chlorophenyl, lower alkyl phenyl, lower hydroxyalkyl phenyl or naphthyl and D' is phenyl, naphthyl, styryl, or a bivalent group selected from ethenylene, phenylene and p,ω-styrylene which bivalent group is substituted by a group of the formula ##STR63## in which A, R and E are as defined above, which radical D' may be substituted by carboxy, lower carboalkoxy, cyano, or nitro.
Claim 3
Dependent Claim
77 words
A compound as defined in claim 1, wherein A is phenyl, mono- or di-(lower alkyl)-phenyl, indanyl, tetrahydronaphthyl or naphthyl; R is hydrogen or methyl; E is phenyl or chlorophenyl and D' is phenyl, cyanophenyl, carboxyphenyl, lower carboalkoxyphenyl, or nitrophenyl; naphthyl, cyanonaphthyl, carboxynaphthyl, lower carboalkoxynaphthyl; styryl, or a bivalent group selected from ethenylene, phenylene and p,ω-styrylene which bivalent group is substituted by a group of the formula ##STR64## in which A, R and E are as defined above.
Claim 4
Dependent Claim
36 words
A compound as defined in claim 1, wherein A is phenyl, tolyl, xylyl, tert.-butyl phenyl, indanyl or naphthyl, R is hydrogen or methyl, E is phenyl or chlorophenyl and D' is phenyl, cyanophenyl or styryl ##STR65##
Claim 5
Dependent Claim
15 words
A compound as defined in claim 1, wherein R is hydrogen and E is phenyl.
Claim 6
Dependent Claim
21 words
The compound as defined in claim 1, wherein A is phenyl, R is hydrogen, E is phenyl and D' is p-cyanophenyl.
References Cited (Backward Citations)
US3864390A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-10-03 | 1981-04-04 | 1981-10-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-10-03 | 1985-04-04 | 1985-10-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-10-03 | 1989-04-04 | 1989-10-04 | $7700.00 | Window Closed / Lapsed |