US4024067A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Processes for the preparation of bis-benzoins and bis-benzils
Assignee: United States Department of the Navy
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Filing: 1976-01-07
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Granted: 1977-05-17
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Expires: 1996-01-07
Abstract
Abstract Bis-benzoins of the formula ##STR1## wherein R is meta-phenylene or para-phenylene are prepared by first conting aldehydes of the formula ##STR2## with sodium bisulfite to form bisulfite addition products of the formula ##STR3## THEN CONTACTING THE BISULFITE ADDITION PRODUCTS WITH EITHER POTASSIUM CYANIDE OR SODIUM CYANIDE TO FORM CYANOHYDRINS OF THE FORMULA ##STR4## and finally contacting the cyanohydrins with benzaldehyde to form the bis-benzoins. The bis-benzoins can be oxidized to form the corresponding bis-benzils which are useful as starting materials for producing phenylated polyquinoxalines which in turn are useful as coatings for fibers, graphite precursors, films and laminating materials.
Inventors
- 👤 Kazimiera J. L. Paciorek
- 👤 Reinhold H. Kratzer
- 👤 Dennis W. Karle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:03
CPC Classifications
C; C07; C07C; C07C49/00; C07C49/76; C07C49/82; C07C49/83; C07C45/00; C07C45/27; C07C45/29; C07C45/45
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
18 words
A bis-benzoin having the formula ##STR15## wherein R is selected from the group consisting of meta-phenylene and para-phenylene.
Claim 2
Dependent Claim
18 words
A bis-benzoin having the formula ##STR15## wherein R is selected from the group consisting of meta-phenylene and para-phenylene.
Claim 3
Dependent Claim
9 words
The bis-benzoin of claim 1 wherein R is para-phenylene.
References Cited (Backward Citations)
US3498981A
Cited
US3595922A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-05-16 | 1980-11-15 | 1981-05-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-16 | 1984-11-15 | 1985-05-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-16 | 1988-11-15 | 1989-05-17 | $7700.00 | Window Closed / Lapsed |