Triphenylphosphine → 6-[(2,3,4-tri-O-acetyl-5-thio-beta-D-xylopyranosyl)oxy]-1H-indole-1-carboxylic Acid, 1,1-dimethylethyl Ester

Participants

Reaction Conditions

Reaction Steps

A solution of 2.66 g (11.41 mM) of 6-hydroxy-1H-indole-1-carboxylic acid tert-butyl ester in 50 ml of THF, 4.16 g (20.6 mM) of diisopropylazodicarboxylate and 5.39 g (20.6 mM) of triphenylphosphine are added to a solution of 4.34 g (14.84 mM) of 2,3,4-tri-O-acetyl-5-thio-D-xylopyranose in 150 ml of THF. The reaction mixture is stirred at 50° C. for 4 hours and then concentrated under reduced pressure. The evaporation residue is solubilized in ethyl acetate and the organic phase is washed with a 1N solution of sodium hydroxide and then with a concentrated aqueous solution of ammonium chloride. The organic phase is subsequently dried over magnesium sulfate and concentrated under reduced pressure. The evaporation residue is purified by silica gel chromatography, elution being carried out with a methylcyclohexane/ethyl acetate mixture (gradient of 9/1 to 7/3; v/v). The residue obtained is subsequently purified by C18-grafted silica chromatography, elution being carried out with an acetonitrile/water mixture (6/4; v/v). The desired product is obtained in the form of a white solid with a yield of 3%.

Provenance & Evidence