Patent US4177917A successfully refreshed from Google Patents.
Patent US3882135A successfully refreshed from Google Patents.
US3882135A
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Process for the preparation of aminopyridines
Assignee: Dow Chemical Co
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Filing: 1973-11-01
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Granted: 1975-05-06
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Expires: 1993-11-01
Abstract
Abstract There is disclosed herein a process for the preparation of aromatic amines and carbamates by reacting certain carbocyclic and heterocyclic aromatic compounds, ring-substituted with at least one displaceable substituent, with alkali metal cyanates and water or an alkanol in the presence of a high dielectricaprotic solvent.
Inventors
- 👤 Richard Garth Pews
- 👤 Lennon H Mckendry
- 👤 Ralph M Rodia
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:02
CPC Classifications
C; C07; C07D; C07D251/00; C07D251/02; C07D251/12; C07D251/26; C07D251/30; C07D251/34; C07C; C07C271/00; C07C271/06; C07D213/00; C07D213/02; C07D213/04; C07D213/60; C07D213/72; C07D213/73
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
71 words
A PROCESS FOR THE PREPARATION OF AN AMINOPYRIDINE COMPOUND WHICH COMPRISES REACTING A PYRIDINE COMPOUND, RINGSUBSTITUTED WITH AT LEAST HONE DISPLACEABLE SUBSTITUENT SELECTED FROM THE GROUP CONSISTING OF CHLORO, BROMO, FLUORO, IODO, N+2, -OSO2R, AND -SR+2, WHEREIN EACH R INDEPENDENTLY REPRESENTS HYDROGEN, PHENYL OR A LOWERALKYL RADICAL OF FROM ONE TO ABOUT 4 CARBON ATOMS, INCLUSIVE, WITH AN ALKALI METAL CYANATE IN THE PRESENCE OF A HIGH DIELECTRIC-APROTIC SOLVENT AND WATER.
Claim 2
Dependent Claim
71 words
A PROCESS FOR THE PREPARATION OF AN AMINOPYRIDINE COMPOUND WHICH COMPRISES REACTING A PYRIDINE COMPOUND, RINGSUBSTITUTED WITH AT LEAST HONE DISPLACEABLE SUBSTITUENT SELECTED FROM THE GROUP CONSISTING OF CHLORO, BROMO, FLUORO, IODO, N+2, -OSO2R, AND -SR+2, WHEREIN EACH R INDEPENDENTLY REPRESENTS HYDROGEN, PHENYL OR A LOWERALKYL RADICAL OF FROM ONE TO ABOUT 4 CARBON ATOMS, INCLUSIVE, WITH AN ALKALI METAL CYANATE IN THE PRESENCE OF A HIGH DIELECTRIC-APROTIC SOLVENT AND WATER.
Claim 3
Dependent Claim
32 words
The process of claim 1 wherein the high dielectric-aprotic solvent is selected from the group consisting of acetonitrile, dimethyl sulfoxide, dimethyl formamide, diglyme, monoglyme acetone, methyl ethyl ketone, dioxane, tetrahydrofuran and N-methylpyrrolidone.
Claim 4
Dependent Claim
22 words
The process of claim 1 wherein the alkali metal cyanate is selected from the group consisting of sodium, potassium, lithium and cesium.
Claim 5
Dependent Claim
36 words
The process of claim 1 wherein the high dielectric-aprotic solvent is selected from the group consisting of acetonitrile and N-methylpyrrolidone, and wherein the alkali metal cyanate is selected from the group consisting of sodium and potassium.
Claim 6
Dependent Claim
21 words
The process of claim 1 wherein the reaction is carried out at a temperature of from about 20* to about 200*C.
Claim 7
Dependent Claim
22 words
The process of claim 1 wherein the reaction is carried out at the boiling temperature of the reaction mixture under reflux conditions.
Claim 8
Dependent Claim
12 words
The process of claim 1 wherein the ring-substituted pyridine compound is pentachloropyridine.
Claim 9
Dependent Claim
19 words
The process of claim 1 wherein pentachloropyridine is reacted with sodium cyanate in the presence of N-methylpyrrolidone and water.
References Cited (Backward Citations)
US3584028A
Cited
US3773695A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-05 | 1978-11-04 | 1979-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-05 | 1982-11-04 | 1983-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-05 | 1986-11-04 | 1987-05-06 | $7700.00 | Window Closed / Lapsed |