US4240961A
Expired / Lapsed
US
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Synthesis of 2-piperazinones and 1,4-diaza-2-keto-cycloheptanes
Assignee: Goodrich Corp
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Filing: 1979-05-29
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Granted: 1980-12-23
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Expires: 1999-05-29
Abstract
Abstract Substituted 2-piperazinones are prepared by reacting a substituted 1,2-diamine with (a) an acyclic or cyclic cyanohydrin acetate, (b) a haloform, and (c) alkali metal hydroxide, in the presence of a suitable organic solvent, at ambient pressure and temperature preferably lower than about 20° C. In an analogous manner, substituted 1,4-diaza-2-keto-cycloheptanes are prepared by reacting substituted 1,3-propane-diamines. In this synthesis, referred to as "the cyanohydrin acetate synthesis," the reaction is accelerated with a phase transfer catalyst selected from the group consisting of a polyether, an onium salt, and a tertiary amine. This synthesis yields predominantly a 2-keto-diazacycloalkane with substituents desirably substituted on carbon atoms on either side of the N 4 atom of the diaza ring.
Inventors
- 👤 John T. Lai
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:44
CPC Classifications
C; C07; C07D; C07D241/00; C07D241/36; C07D241/38; C07D241/02; C07D241/06; C07D241/08; C07D243/00; C07D243/06; C07D243/08; C07D243/10
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
76 words
A method for preparing a polysubstituted 2-keto-1,4-diazacycloalkane compound comprising reacting a diamine selected from the group consisting of an acyclic 1,2-diamine and an acyclic 1,3-diamine, with a cyanohydrin acetate selected from the group consisting of an acyclic cyanohydrin acetate and a cyclic cyanohydrin acette, in the presence of (i) alkali metal hydroxide, and (ii) a haloform; forming a piperazinone when said 1,2-diamine is reacted, and a 1,4-diazepin-2-one when said 1,3-diamine is reacted; and, recovering said compound.
Claim 2
Independent Claim
76 words
A method for preparing a polysubstituted 2-keto-1,4-diazacycloalkane compound comprising reacting a diamine selected from the group consisting of an acyclic 1,2-diamine and an acyclic 1,3-diamine, with a cyanohydrin acetate selected from the group consisting of an acyclic cyanohydrin acetate and a cyclic cyanohydrin acette, in the presence of (i) alkali metal hydroxide, and (ii) a haloform; forming a piperazinone when said 1,2-diamine is reacted, and a 1,4-diazepin-2-one when said 1,3-diamine is reacted; and, recovering said compound.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein said alkali metal hydroxide is added as an aqueous solution in an amount from about one equivalent to about three equivalents per mol of said diamine.
Claim 4
Dependent Claim
40 words
The method of claim 1 wherein said acyclic 1,2-diamine and said acyclic 1,3-diamine are substituted diamines having substituents selected from aryl, cycloalkyl having from 4 to about 7 ring members, and alkyl having from 1 to about 30 carbon atoms.
Claim 5
Dependent Claim
17 words
The method of claim 1 including adding an organic solvent for said diamines and said cyanohydrin acetate.
Claim 6
Dependent Claim
37 words
The method of claim 4 including adding a phase transfer catalyst selected from the group consisting of an onium salt, a triamine and a polyether in an amount sufficient to accelerate formation of said polysubstituted 2-keto-1,4-diazacycloalkane compound.
Claim 7
Dependent Claim
38 words
The method of claim 4 wherein said cyclic cyanohydrin acetate is a cycloalkanone cyanohydrin acetate and said acyclic cyanohydrin acetate is an alkyl cyanohydrin acetate having a carbonyl moiety; and, said haloform is selected from chloroform and bromoform.
Claim 8
Dependent Claim
21 words
The method of claim 6 wherein said polysubstituted compound is formed at substantially ambient pressure and temperature below about 20° C.
Claim 9
Dependent Claim
39 words
The method of claim 7 wherein said polysubstituted compound is provided on each carbon atom adjacent the N 4 atom, with (a) two acyclic substituents, or, (b) two acyclic substituents and one cyclic substituent, or, (c) one cyclic substituent.
Claim 10
Dependent Claim
12 words
The method of claim 8 wherein said phase transfer catalyst is polyether.
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) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |