Hydrochloric Acid → 2-Carbobenzyloxy-3,4,5-trimethoxybenzoic Acid

HRID 48091

Reaktionsgleichung

C([Li])(C)(C)C.Br[C:7]1[C:15]([O:16][CH3:17])=[C:14]([O:18][CH3:19])[C:13]([O:20][CH3:21])=[CH:12][C:8]=1[C:9]([OH:11])=[O:10].Cl[C:23]([O:25][CH2:26][C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)=[O:24].Cl>C1COCC1.O>[C:23]([C:7]1[C:15]([O:16][CH3:17])=[C:14]([O:18][CH3:19])[C:13]([O:20][CH3:21])=[CH:12][C:8]=1[C:9]([OH:11])=[O:10])([O:25][CH2:26][C:27]1[CH:32]=[CH:31][CH:30]=[CH:29][CH:28]=1)=[O:24]

Komponenten

Reaktionsbedingungen

Temperatur: -78 °C

Versuchsvorschrift

tert-Butyllithium (1.7M solution in pentane, 15 mmol) is added to a solution of 2-bromo-3,4,5-trimethoxybenzoic acid 5 (5 mmol) in 50 mL of THF, while maintaining the temperature of the mixture below −95° C. After the addition is completed, the mixture is allowed to warm to −78° C. After 30 minutes, benzyl chloroformate (5 mmol) is added in one portion, and the mixture is allowed to warm to 0° C. Water (50 mL) is added, and then the pH of the mixture is carefully adjusted to 3 using 0.1 M HCl. The mixture is extracted with ethyl acetate (5×100 mL). The organic phases are dried over anhydrous Na2SO4 and concentrated in vacuo. The mixture is purified by flash chromatography to give the product as a colorless oil.

Aufarbeitung

temperaturewhile maintaining the temperature of the mixture below −95° C
additionAfter the addition
temperatureto warm to 0° C
extractionThe mixture is extracted with ethyl acetate (5×100 mL)
dry with materialThe organic phases are dried over anhydrous Na2SO4
concentrationconcentrated in vacuo
customThe mixture is purified by flash chromatography

Quellen und Nachweise

ORD-Eintrag: ord-a3cf441131134349983899454780a999
Quelldatensatz: uspto-grants-2004_03
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US06702705B1

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