US3887550A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing heterocyclic acid anhydrides
Assignee: PMC Inc
•
Filing: 1969-11-20
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Granted: 1975-06-03
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Expires: 1989-11-20
Abstract
Abstract A method for producing heterocyclic acid anhydrides and pyrimidinediones from the corresponding acids, dicarboxamides, 2,3-and 3,4-pyridinedicarboxamides, and N-monosubstituted 2,3-and 3,4-pyridinedicarboxamides, in which the aforesaid compounds are reacted with lead tetra-acetate in the presence of a suitable anhydrous inert solvent. Heterocyclic acid anhydrides are useful as intermediates in the production of pharmaceuticals, agricultural chemicals, and anthranilic acid esters used as perfume essences and flavoring materials. Pyrimidinediones and ring substituted analogues are useful as agricultural chemicals, especially as herbicides.
Inventors
- 👤 Athelstan L J Beckwith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:15
CPC Classifications
C; C07; C07D; C07D265/00; C07D265/04; C07D265/12; C07D265/14; C07D265/24; C07D265/26; C07D213/00; C07D213/02; C07D213/04; C07D213/24; C07D213/54; C07D213/56; C07D239/00; C07D239/70; C07D239/72; C07D239/95; C07D239/96; C07D471/00; C07D471/02; C07D471/04; C07D475/00; C07D475/02
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
10 words
A METHOD FOR PRODUCING HETEROCYCLIC ACID ANHYDRIDES HAVING THE FORMULA,
Claim 2
Independent Claim
10 words
A METHOD FOR PRODUCING HETEROCYCLIC ACID ANHYDRIDES HAVING THE FORMULA,
Claim 3
Independent Claim
10 words
A method for producing heterocyclic acid anhydrides having the formula,
Claim 4
Independent Claim
10 words
A method for producing heterocyclic acid anhydrides having the formula,
Claim 5
Dependent Claim
15 words
A method as claimed in claim 1 wherein the second named reactant is phthalamic acid.
References Cited (Backward Citations)
GB1135789A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |