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US4146714A
Expired / Lapsed
US
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Preparation of Δ-2 tetrahydropyrimidines
Assignee: Baker Petrolite LLC
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Filing: 1977-06-01
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Granted: 1979-03-27
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Expires: 1997-06-01
Abstract
Abstract A process of converting 2,3,4,5-tetrahydropyrimidines (Δ-1) having at least one hydrogen in the 2-position to 3,4,5,6-tetrahydropyrimidines (Δ-2), which comprises hydrogenating and dehydrogenating said Δ-1 tetrahydropyrimidines. Such hydrogenating and dehydrogenating may be done in either two sequential steps or in one step. Said Δ-1 tetrahydropyrimidines can also be converted to Δ-2 tetrahydropyrimidines by heating in the essential absence of a solvent, and preferably under basic conditions. In addition, corresponding hexahydropyrimidines can be converted to corresponding Δ-2 tetrahydropyrimidines by dehydrogenation. This invention also relates to the use of Δ-2 tetrahydropyrimidines, particularly as corrosion inhibitors.
Inventors
- 👤 Bernardus A. O. Alink
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 19:47
CPC Classifications
C; C07; C07D; C07D239/00; C07D239/02; C07D239/06; C07D239/24; C07D239/28; C07D239/32; C07D239/38; C07D239/46; C07D239/47; C07D239/56; C07D239/60; C23; C23F; C23F11/00; C23F11/08; C23F11/10; C23F11/14; C23F11/149
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
35 words
A process of converting 2,3,4,5-tetrahydropyrimidines (Δ-1) having at least one hydrogen in the 2-position to 3,4,5,6-tetrahydropyrimidines (Δ-2) which comprises the steps of hydrogenating and dehydrogenating said Δ-1 compounds in the presence of a hydrogenation-dehydrogenation catalyst.
Claim 2
Dependent Claim
35 words
A process of converting 2,3,4,5-tetrahydropyrimidines (Δ-1) having at least one hydrogen in the 2-position to 3,4,5,6-tetrahydropyrimidines (Δ-2) which comprises the steps of hydrogenating and dehydrogenating said Δ-1 compounds in the presence of a hydrogenation-dehydrogenation catalyst.
Claim 3
Dependent Claim
14 words
The process of claim 1 where hydrogenating and dehydrogenating is done in two steps.
Claim 4
Dependent Claim
14 words
The process of claim 1 where hydrogenating and dehydrogenating is done in one step.
Claim 5
Dependent Claim
31 words
A process of converting hexahydropyrimidines having at least one hydrogen in the 2-position to 3,4,5,6-tetrahydropyrimidines (Δ-2) which comprises the step of dehydrogenating said hexahydropyrimidines in the presence of a dehydrogenation catalyst.
Claim 6
Dependent Claim
31 words
A process of converting hexahydropyrimidines having at least one hydrogen in the 2-position to 3,4,5,6-tetrahydropyrimidines (Δ-2) which comprises the step of dehydrogenating said hexahydropyrimidines in the presence of a dehydrogenation catalyst.
Claim 7
Dependent Claim
47 words
A process of converting 2,3,4,5-tetrahydropyrimidines (Δ-1) having one hydrogen in the 2-position and an aromatic radical in the 2-position to the corresponding 3,4,5,6-tetrahydropyrimidines (Δ-2) which comprises heating said Δ-1 compound in the absence of a solvent or under basic conditions so as to form the Δ-2 compound.
Claim 8
Dependent Claim
47 words
A process of converting 2,3,4,5-tetrahydropyrimidines (Δ-1) having one hydrogen in the 2-position and an aromatic radical in the 2-position to the corresponding 3,4,5,6-tetrahydropyrimidines (Δ-2) which comprises heating said Δ-1 compound in the absence of a solvent or under basic conditions so as to form the Δ-2 compound.
Claim 9
Dependent Claim
15 words
The process of claim 5 which is carried out in the absence of a solvent.
Claim 10
Dependent Claim
12 words
The process of claim 5 which is carried out under basic conditions.
Claim 11
Dependent Claim
14 words
The process of claim 5 where the base is sodium hydroxide or potassium hydroxide.
Claim 12
Dependent Claim
15 words
The process of claim 5 where the aromatic radical is phenyl, methoxyphenyl, furyl or pyridyl.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-26 | 1982-09-25 | 1983-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-26 | 1986-09-25 | 1987-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-26 | 1990-09-25 | 1991-03-27 | $7700.00 | Window Closed / Lapsed |