US4209446A
Expired / Lapsed
US
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Process for the preparation of piperonylidenecrotonic acid amides
Assignee: Haarmann and Reimer GmbH
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Filing: 1978-12-13
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Granted: 1980-06-24
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Expires: 1998-12-13
Abstract
Abstract Process for the preparation of piperonylidenecrotonic acid amides of the formula <IMAGE> in which R1 and R2 have the meaning given in the disclosure wherein piperonal is reacted with crotonic acid amides of the formula <IMAGE> in the presence of alkali metal hydroxides and dipolar aprotic diluents which are inert under the reaction conditions.
Inventors
- 👤 Andreas Schulze
- 👤 Hermann Oediger
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:55
CPC Classifications
C; C07; C07D; C07D317/00; C07D317/08; C07D317/44; C07D317/46; C07D317/48; C07D317/50; C07D317/60
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
114 words
A process for the preparation of a piperonylidenecrotonic acid amide of the formula ##STR12## in which R 1 and R 2 independently of one another represent hydrogen or an optionally substituted aliphatic, araliphatic or aromatic hydrocarbon radical, or, together with the nitrogen atom, form a heterocyclic ring, with the proviso that R 1 and R 2 do not simultaneously denote hydrogen, comprising reacting piperonal with a crotonic acid amide of the formula ##STR13## in which R 1 and R 2 have the meaning indicated above, in the presence of 0.05 to 0.5 mol of an alkali metal hydroxide per mol of piperonal and a dipolar aprotic diluent which is inert under the reaction conditions.
Claim 2
Dependent Claim
114 words
A process for the preparation of a piperonylidenecrotonic acid amide of the formula ##STR12## in which R 1 and R 2 independently of one another represent hydrogen or an optionally substituted aliphatic, araliphatic or aromatic hydrocarbon radical, or, together with the nitrogen atom, form a heterocyclic ring, with the proviso that R 1 and R 2 do not simultaneously denote hydrogen, comprising reacting piperonal with a crotonic acid amide of the formula ##STR13## in which R 1 and R 2 have the meaning indicated above, in the presence of 0.05 to 0.5 mol of an alkali metal hydroxide per mol of piperonal and a dipolar aprotic diluent which is inert under the reaction conditions.
Claim 3
Dependent Claim
30 words
A process according to claim 1, wherein the inert dipolar aprotic diluent is a dialkylformamide, dialkylacetamide, 1-methyl-2-pyrrolidinone, a tetraalkylurea, a dialkylsulphoxide, a sulphone, a hexaalkyl phosphoric acid triamide or 1-methyl-1-oxo-phospholine.
Claim 4
Dependent Claim
14 words
A process according to claim 2, wherein the inert dipolar aprotic diluent is dimethylsulphoxide.
References Cited (Backward Citations)
US2951853A
Cited
US4021574A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-06-24 | 1983-12-24 | 1984-06-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-06-24 | 1987-12-24 | 1988-06-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-06-24 | 1991-12-24 | 1992-06-24 | $7700.00 | Window Closed / Lapsed |