Veratraldehyde → 3-(3,4-Dimethoxyphenyl)propionic acid

HRID 36406

Reaktionsgleichung

Reaktionsgleichung von HRID 36406
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:18]=[CH:19][C:20]=1[O:21][CH3:22])[CH2:6][CH:7](C(OCC)=O)[C:8]([O:10][CH2:11][CH3:12])=[O:9].C(=O)C1C=CC(OC)=C(OC)C=1.CC1(C)OC(=O)CC(=O)O1>C(O)C.C(N(CC)CC)C.C(O)=O>[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:18]=[CH:19][C:20]=1[O:21][CH3:22])[CH2:6][CH2:7][C:8]([OH:10])=[O:9].[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:18]=[CH:19][C:20]=1[O:21][CH3:22])[CH2:6][CH2:7][C:8]([O:10][CH2:11][CH3:12])=[O:9]

Komponenten

8

Edukt 3

HCID 8419VeratraldehydeHCID 162492,2-Dimethyl-1,3-dioxane-4,6-dioneHCID 12249516Propanedioic acid, [(3,4-dimethoxyphenyl)methyl]-, diethyl ester

Produkt 2

HCID 750193-(3,4-Dimethoxyphenyl)propionic acidHCID 222974Ethyl 3-(3,4-dimethoxyphenyl)propionate

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 284Formic AcidLösungsmittel2×HCID 702EthanolLösungsmittelHCID 8471TriethylamineLösungsmittel2×

Versuchsvorschrift

By boiling Meldrum's acid (formula III with R9 =R10 =methyl group) with veratraldehyde in an ethanolic medium in the presence of formic acid and triethylamine, monoethyl 3,4-di-(methoxy)-benzylmalonate was obtained. According to our experimental observation, diethyl 3,4-di-(methoxy)-benzylidene malonate could not be hydrogenated to diethyl 3,4-di-(methoxy)-benzylmalonate when using formic acid and triethylamine as reagents. Furtheron we have observed that by reacting veratraldehyde with Meldrum's acid, formic acid and triethylamine at 100° C. for 2 hours and then by boiling with ethanol for 2 hours 3,4-dimethoxyhydrocinnamic acid and not ethyl 3,4-di-(methoxy)-hydrocinnamate was obtained as final product. Thus, the reaction can be interpreted only in such a way that 5-[3',4'-di-(methoxy)-phenylmethyl]-Meldrum's acid is formed in the manner described above, the dioxane ring of which is opened and one carboxyl group of the 3,4-di-(methoxy)-benzylmalonic acid formed is simultaneously esterified. When the temperature of the reaction mixture is increased after removing the ethanol, the carboxyl group is eliminated and 3,4-di-(methoxy)-hydrocinnamic acid ester is obtained.

Aufarbeitung

  1. customat 100° C.
  2. customfor 2 hours

Quellen und Nachweise

ORD-Eintrag
ord-a7cbb12e0ad14dbc820c7675eb0a1847
Quelldatensatz
uspto-grants-1995_05
Patentnummer
US05414108

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