US3004027A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for purification of 3,6-dichloropyridazine
Assignee: Wyeth Holdings LLC
•
Filing: 1957-05-01
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Granted: 1961-10-10
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Expires: 1977-05-01
Abstract
No abstract record available.
Inventors
- 👤 Gordon John Edson
- 👤 Goodemoot Kenneth
- 👤 Dorf Fred Bernard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 13:09
CPC Classifications
C; C07; C07D; C07D237/00; C07D237/02; C07D237/06; C07D237/10; C07D237/12
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
107 words
IN RECOVERING 3,6-DICHLOROPYRIDAZINE FROM A REACTION PRODUCT OBTAINED BY THE ACTION OF PHOSPHOROUS OXYCHLORIDE ON MALEIC HYDRAZIDE, SAID REACTION PRODUCT CONTAINING A FINITE AMOUNT OF RESIDUAL UNREACTED PHOSPHOROUS OXYCHLORIDE, THE IMPROVEMENT WHICH PERMITS RECOVERY OF SAID 3,6 - DICHLOROPYRIDAZINE CONTAINING NOT OVER 2% IMPURITIES, SAID IMPROVEMENT COMPRISING THE STEPS OF DROWNING SAID REACTION PRODUCT IN WATER, TREATING THE RESULTANT MASS COMPRISING DROWNED PRODUCT IN DROWNING LIQUOR WITH AT LEAST 10 PARTS PER HUNDRED PARTS BY WEIGHT OF SAID REACTION PRODUCT OF A WATERSOLUBLE SULFITE SELECTED FROM THE GROUP CONSISTING OF THE BISULFITES, OF SODIUM, POTASSIUM AND AMMONIUM, PRECIPITATING 3,6-DICHLOROPYRIDAZINE FROM THE SO-TREATED MASS AND COLLECTING RESULTANT PRECIPITATE.
Claim 2
Dependent Claim
107 words
IN RECOVERING 3,6-DICHLOROPYRIDAZINE FROM A REACTION PRODUCT OBTAINED BY THE ACTION OF PHOSPHOROUS OXYCHLORIDE ON MALEIC HYDRAZIDE, SAID REACTION PRODUCT CONTAINING A FINITE AMOUNT OF RESIDUAL UNREACTED PHOSPHOROUS OXYCHLORIDE, THE IMPROVEMENT WHICH PERMITS RECOVERY OF SAID 3,6 - DICHLOROPYRIDAZINE CONTAINING NOT OVER 2% IMPURITIES, SAID IMPROVEMENT COMPRISING THE STEPS OF DROWNING SAID REACTION PRODUCT IN WATER, TREATING THE RESULTANT MASS COMPRISING DROWNED PRODUCT IN DROWNING LIQUOR WITH AT LEAST 10 PARTS PER HUNDRED PARTS BY WEIGHT OF SAID REACTION PRODUCT OF A WATERSOLUBLE SULFITE SELECTED FROM THE GROUP CONSISTING OF THE BISULFITES, OF SODIUM, POTASSIUM AND AMMONIUM, PRECIPITATING 3,6-DICHLOROPYRIDAZINE FROM THE SO-TREATED MASS AND COLLECTING RESULTANT PRECIPITATE.
References Cited (Backward Citations)
US1401937A
Cited
US2846433A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-10-09 | 1965-04-10 | 1965-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-10-09 | 1969-04-10 | 1969-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-10-09 | 1973-04-10 | 1973-10-10 | $7700.00 | Window Closed / Lapsed |