Water → Methyl 5-(1,3-dioxolan-2-yl)-1-benzofuran-2-carboxylate

HRID 2261109

Reaktionsgleichung

[O:1]1[CH2:5][CH2:4][O:3][CH:2]1[C:6]1[CH:7]=[CH:8][C:9]2[O:13][CH:12]=[CH:11][C:10]=2[CH:14]=1.C([Li])CCC.C([C:22]([O:24][CH3:25])=[O:23])#N.O>C1COCC1.C(OCC)(=O)C>[CH3:25][O:24][C:22]([C:12]1[O:13][C:9]2[CH:8]=[CH:7][C:6]([CH:2]3[O:3][CH2:4][CH2:5][O:1]3)=[CH:14][C:10]=2[CH:11]=1)=[O:23]

Komponenten

Reaktionsbedingungen

Temperatur: -78 °C

Versuchsvorschrift

5-[1,3]Dioxolan-2-yl-benzofuran (50 mg, 0.26 mmol) was dissolved in THF (2 mL) and the solution was cooled down to −78° C. Butyl lithium (180 uL, 1.1 eq.) was added dropwise. This mixture was stirred 30 min at 25° C. Then the reaction mixture was cooled down to −78° C. and methyl cyanoformate (23 uL, 1.1 eq.) dissolved in 1 mL THF was added dropwise to the reaction mixture. After 1 h30 only small amount of starting material was detected and two major compounds were formed (expected product/dimer 73:27). The temperature was increased slowly to room temperature overnight. Water and ethyl acetate were added to the mixture and the aqueous layer was extracted 3 times. Combined organic phases was dried over MgSO4, filtrated and evaporated to give the 5-[1,3]Dioxolan-2-yl-benzofuran-2-carboxylic acid methyl ester (31.9 mg, 44%) mixed with the dimer (expected product/dimer 46:54). The mixture was used directly in the next step.

Aufarbeitung

temperatureThen the reaction mixture was cooled down to −78° C.
additionwas added dropwise to the reaction mixture
customtwo major compounds were formed (expected product/dimer 73:27)
temperatureThe temperature was increased slowly to room temperature overnight
extractionthe aqueous layer was extracted 3 times
dry with materialCombined organic phases was dried over MgSO4
filtrationfiltrated
customevaporated

Quellen und Nachweise

ORD-Eintrag: ord-9f8766ef6ed74d65befc2074df2ffced
Quelldatensatz: uspto-grants-2010_12
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US07846925B2

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