1,8-Diazabicyclo(5.4.0)undec-7-ene → 2-[2-(4-Hydroxymethylphenyl)vinyl]-5-benzofurancarbonitrile

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Reaction Steps

911 mg of 4-hydroxymethylbenzaldehyde and 2.0 g of (5-cyano-2-benzofuranyl)methyltriphenylphosphonium chloride were dissolved in a solvent mixture of 10 ml of tetrahydrofuran and 10 ml of ethanol, followed by the addition of 845 mg of 1,8-diazabicyclo[5.4.0]-7-undecene and by subsequent stirring at room temperature for 1 hour. After distilling off the solvent, the resulting residue was purified by subjecting it to silica gel column chromatography, thereby obtaining 2.3 g of 2-[2-(4-hydroxymethylphenyl)vinyl]-5-benzofurancarbonitrile as a mixture of E and Z forms. 2.3 g of the thus obtained E/Z mixture was dissolved in a solvent mixture of 10 ml of tetrahydrofuran and 10 ml of ethanol, and the solution was subjected to catalytic hydrogenation under normal pressure for 7 hours in the presence of 800 mg of palladium oxide.1H2O.barium sulfate. After removing the catalyst by filtration and distilling off the solvent, the resulting residue was purified by subjecting it to silica gel column chromatography using chloroform as an elution solvent to obtain 835 mg of 2-[2-(4-hydroxymethylphenyl)ethyl]-5-benzofurancarbonitrile as crystals.

Provenance & Evidence