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Patent US4804753A successfully refreshed from Google Patents.
US4804753A
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Process for the preparation of Schiff's bases
Assignee: Bayer AG
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Filing: 1986-01-08
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Granted: 1989-02-14
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Expires: 2006-01-08
Abstract
Abstract A process for the preparation of Schiff's bases which contain amino groups, of the formula ##STR1## wherein n is 3 to 12, by reacting cyclic lactams of the formula ##STR2## wherein n is 3 to 12, or of their ring-opened polymers of the formula ##STR3## wherein n is 3 to 12 and m is 1 to 100,000, with inorganic bases at elevated temperature, the reaction being carried out in the presence of inert, high-boiling suspending agents.
Inventors
- 👤 Hans-Helmut Schwarz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 02:02
CPC Classifications
C; C07; C07D; C07D207/00; C07D207/02; C07D207/18; C07D207/20; C07D223/00; C07D223/02; C07D223/04
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
133 words
In a process for the preparation of Schiff's bases of the formula ##STR7## wherein n is 3 to 12, by reacting cyclic lactams of the formula ##STR8## wherein n is 3 to 12, on their ring-opened polymers of the formula ##STR9## wherein n is 3 to 12 and m is 1 to 100,000, with an inorganic base at an elevated temperature, wherein the improvement comprises the reaction being carried out in the presence of inert, high-boiling suspending agents selected from the group consisting of high-boiling aliphatic hydrocarbons, high-boiling aromatic hydrocarbons, mixtures of said aliphatic and aromatic hydrocarbons, high-boiling polymeric hydrocarbons and high-boiling mineral oil, wherein the amount of the suspending agent is not less than 25% by weight relative to the mixture of all reaction components, to result in a stirrable reaction mixture.
Claim 2
Dependent Claim
133 words
In a process for the preparation of Schiff's bases of the formula ##STR7## wherein n is 3 to 12, by reacting cyclic lactams of the formula ##STR8## wherein n is 3 to 12, on their ring-opened polymers of the formula ##STR9## wherein n is 3 to 12 and m is 1 to 100,000, with an inorganic base at an elevated temperature, wherein the improvement comprises the reaction being carried out in the presence of inert, high-boiling suspending agents selected from the group consisting of high-boiling aliphatic hydrocarbons, high-boiling aromatic hydrocarbons, mixtures of said aliphatic and aromatic hydrocarbons, high-boiling polymeric hydrocarbons and high-boiling mineral oil, wherein the amount of the suspending agent is not less than 25% by weight relative to the mixture of all reaction components, to result in a stirrable reaction mixture.
Claim 3
Dependent Claim
17 words
A process according to claim 1, wherein the inert high-boiling suspending agent is a high-boiling mineral oil.
Claim 4
Dependent Claim
44 words
A process according to claim 2, wherein the high-boiling mineral oil is an oil having a boiling point ≧250° C. selected from the group consisting of gas oil, vacuum gas oil, heavy fuel oil, technical white oil, molten paraffin wax and aromatic hydrocarbon oil.
Claim 5
Dependent Claim
27 words
A process according to claim 1, wherein the inert high-boiling suspending agent is a vacuum gas oil which has a boiling range of 350° to 500° C.
Claim 6
Dependent Claim
29 words
A process according to claim 1, wherein the amount of the inert, high-boiling suspending agent is 30 to 70% by weight relative to the mixture of all reaction components.
Claim 7
Dependent Claim
30 words
A process according to claim 1, wherein the inorganic base is selected from the group consisting of alkaline earth oxides, alkaline earth hydroxides, alkali metal oxides and alkali metal hydroxides.
Claim 8
Dependent Claim
13 words
A process according to claim 1, wherein the inorganic base is calcium oxide.
Claim 9
Dependent Claim
12 words
A process according to claim 1, wherein n is 4 to 12.
Claim 10
Dependent Claim
22 words
A process according to claim 1, wherein the cyclic lactam is selected from the group consisting of δ-valerolactam, ε-caprolactam, n-capryllactam and laurolactam.
Claim 11
Dependent Claim
12 words
A process according to claim 1, wherein the cyclic lactam is ε-caprolactam.
Claim 12
Dependent Claim
12 words
A process according to claim 1, wherein m is 100 to 400.
Claim 13
Dependent Claim
20 words
A process according to claim 1, wherein the polymer is selected from the group consisting of nylon-4, nylon-6 and nylon-8.
Claim 14
Dependent Claim
24 words
A process according to claim 1, wherein 0.55 to 0.95 moles of the inorganic base are used per 1 mole of the cyclic lactam.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-14 | 1992-08-15 | 1993-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-14 | 1996-08-15 | 1997-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-14 | 2000-08-15 | 2001-02-14 | $7700.00 | Window Closed / Lapsed |