Citric Acid → 2-[2-[4-[((3S)-1-acetyl-3-pyrrolidinyl)oxy]-3-hydroxyphenyl]vinyl]-5-benzofurancarbonitrile

Participants

Reaction Steps

1.3 g of 3-acetyloxy-4-[((3S)-1-acetyl-3-pyrrolidinyl)oxy]benzaldehyde and 2.22 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 0.943 g of 1,8-diazabicyclo[5.4.0]-7-undecene and by subsequent stirring at room temperature for 2 hours. To the mixture obtained were further added 1.88 g of 1,8-diazabicyclo[5.4.0]-7-undecene and 3 ml of water, followed by stirring at room temperature for 2 hours. The thus prepared reaction solution was adjusted to pH 4-5 with 10% citric acid aqueous solution and concentrated under a reduced pressure, and the resulting residue was extracted with chloroform, and then dried. After distilling off the solvent, the resulting residue was purified by subjecting it to silica gel column chromatography using a chloroform/ethanol mixture as an elution solvent, thereby obtaining 1.8 g of 2-[2-[4-[((3S)-1-acetyl-3-pyrrolidinyl)oxy]-3-hydroxyphenyl]vinyl]-5-benzofurancarbonitrile as a powdery mixture of E and Z forms.

Provenance & Evidence