US3852360A
Expired / Lapsed
US
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Preparation of hydroxycitronellal
Assignee: LAir Liquide SA pour lEtude et lExploitation des Procedes Georges Claude
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Filing: 1970-09-18
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Granted: 1974-12-03
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Expires: 1990-09-18
Abstract
Abstract The invention is concerned with a new process for preparing 7hydroxy dihydrocitronellal. This process consists in causing citronellal to react with a secondary amine, in transforming the derivative obtained, by treatment in aqueous acid medium, into the immonium of the citronellal, which is hydrated, then in hydrolysing the immonium of the hydroxycitronellal thus formed into 7-hydroxy dihydrocitronellal, all these operations being effected in the liquid base.
Inventors
- 👤 M Vilkas
- 👤 G Senechal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 13:27
CPC Classifications
C; C07; C07C; C07C45/00; C07C45/51; C07C45/516; C07C45/61; C07C45/64
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
104 words
A PROCESS FOR THE PREPARATION OF 7-HYDROXY DIHYDROCITRONELLAL, COMPRISING: REACTING CITRONELLAL WTH A SECONDARY LOWER ALKYL AMINE OR PYRROLIDINE, IN LIQUID PHASE, TO PROVIDE AN ENAMINE, AT BETWEEN ABOUT -30*C AND AMBIENT TEMPERATURE; CONVERTING SAID ENAMINE TO THE IMMONIUM OF CITRONELLAL BY TREATMENT IN THE LIQUID PHASE OF SAID ENAMINE IN A 30% TO 70% SOLUTION OF SULFURIC ACID AT BETWEEN ABOUT -30* AND 0*C; HEATING THE RESULTANT REACTION MIXTURE TO AMBIENT TEMPERATURE AND MAINTAINING AT AMBINENT TEMPERATURE TO HYDRATE SAID IMMONIUM CITRONELLAL TO FORM IMMONIUM 7DIHYDROXY CITRONELLAL; HYDROLYSING SAID IMMONIUM 7-DIHYDROXY CITRONELLAL IN THE LIQUID PHASE TO 7-HYDROXY-DIHYDROCITRONELLAL; AND RECOVERING THE 7-HYDROXY DIHYDROCITRONELLAL.
Claim 2
Dependent Claim
104 words
A PROCESS FOR THE PREPARATION OF 7-HYDROXY DIHYDROCITRONELLAL, COMPRISING: REACTING CITRONELLAL WTH A SECONDARY LOWER ALKYL AMINE OR PYRROLIDINE, IN LIQUID PHASE, TO PROVIDE AN ENAMINE, AT BETWEEN ABOUT -30*C AND AMBIENT TEMPERATURE; CONVERTING SAID ENAMINE TO THE IMMONIUM OF CITRONELLAL BY TREATMENT IN THE LIQUID PHASE OF SAID ENAMINE IN A 30% TO 70% SOLUTION OF SULFURIC ACID AT BETWEEN ABOUT -30* AND 0*C; HEATING THE RESULTANT REACTION MIXTURE TO AMBIENT TEMPERATURE AND MAINTAINING AT AMBINENT TEMPERATURE TO HYDRATE SAID IMMONIUM CITRONELLAL TO FORM IMMONIUM 7DIHYDROXY CITRONELLAL; HYDROLYSING SAID IMMONIUM 7-DIHYDROXY CITRONELLAL IN THE LIQUID PHASE TO 7-HYDROXY-DIHYDROCITRONELLAL; AND RECOVERING THE 7-HYDROXY DIHYDROCITRONELLAL.
Claim 3
Dependent Claim
27 words
A process for the preparation of 7-hydroxy-dihydrocitronellal according to claim 1, wherein the amine is a member selected from the group consisting of dimethylamine, diethylamine and pyrrolidine.
Claim 4
Dependent Claim
25 words
A process for the preparation of 7-hydroxy-dihydrocitronellal according to claim 1, wherein 1 to 2 moles of secondary amine are reacted per mole of citronellal.
Claim 5
Dependent Claim
29 words
A process for the preparation of 7-hydroxy-dihydrocitronellal, according to claim 1, wherein the enamine is transformed into the immonium of citronellal by pouring it into said sulfuric acid solution.
Claim 6
Dependent Claim
39 words
A process for the preparation of 7-hydroxycitronellal according to claim 1, wherein the said initially formed derivative is transformed into immonium of citronellal by pouring it into the sulphuric acid with a concentration which is between 42% and 60%.
Claim 7
Dependent Claim
28 words
A process for the preparation of 7-hydroxy-dihydrocitronellal according to claim 1, wherein the acid is used at the rate of 2 to 5 moles per mole of citronellal.
Claim 8
Dependent Claim
30 words
A process for the preparation of 7-hydroxy-dihydrocitronellal according to claim 1, wherein said hydration is carried out by bringing the acid medium containing the immonium of citronellal to ambient temperature.
Claim 9
Dependent Claim
34 words
A process for the preparation of 7-hydroxy-dihydrocitronellal according to claim 1, wherein the acid medium containing the immonium of citronellal is treated with hexane or toluene to eliminate the isopulegal and other impurities formed.
Claim 10
Dependent Claim
74 words
A process for the preparation of 7-hydroxy-dihydrocitronellal, especially from natural oils containing citronellal, according to claim 1, wherein the hydrolysis of the immonium of 7-hydroxy-dihydrocitronellal is effected by neutralising the acid medium by means of an aqueous solution of a strong base and in the presence of hexane or toluene to dissolve the 7-hydroxy-dihydrocitronellal as it forms, while keeping the temperature in limits such that the alkali salt which is formed remains in solution.
Claim 11
Dependent Claim
32 words
A process in accordance with claim 1 wherein said secondary amine is dimethyl amine and wherein said reaction between citronellal and dimethyl amine is carried out at between about -30* and 0*C.
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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |