Patent US3625944A successfully refreshed from Google Patents.
US3625944A
Expired / Lapsed
US
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Method for preparation of chlorinated methyl pyrazines
Assignee: Merck and Co Inc
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Filing: 1968-10-10
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Granted: 1971-12-07
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Expires: 1988-10-10
Abstract
Abstract The direction chlorination of methylpyrazine by heating in a solvent to provide chlorinated 2-methylpyrazine compounds is described. The compounds are useful as intermediates in preparing the therapeutically active (3-aminopyrazinoyl) guanidine products which are effective natriuretic and antikaluretic compounds.
Inventors
- 👤 Edward J J Grabowski
- 👤 Edward W Tristram
- 👤 Roger J Tull
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:29
CPC Classifications
C; C07; C07D; C07D241/00; C07D241/02; C07D241/10; C07D241/12; C07D241/14; C07D241/16; C07D241/24; C07D241/26
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
25 words
A modification of the process claimed in claim 1, wherein the chlorinated methylpyrazine product obtained is caused to react with hydroxylamine to provide a 5-amino-2-(hydroxyiminomethyl)pyrazine.
Claim 2
Dependent Claim
17 words
A process as claimed in claim 2, wherein the reaction mixture is heated at about reflux temperature.
Claim 3
Dependent Claim
20 words
A process as claimed in claims 2 or 3 wherein 2-chloro-3-(dichloromethyl)pyrazine and hydroxylamine are caused to react to provide 5-amino-3-chloro-2-(hydroxyiminomethyl)pyrazine.
References Cited (Backward Citations)
US3344142A
Cited
US3501472A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-12-06 | 1975-06-07 | 1975-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-12-06 | 1979-06-07 | 1979-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-12-06 | 1983-06-07 | 1983-12-07 | $7700.00 | Window Closed / Lapsed |