HCID 20163689, compound → HCID 86741844, compound

Participants

Reaction Steps

A mixture of 8.0 g (0.036 mole) of 3-hydroxy-5-methoxy-2-benzofurancarboxylic acid, methyl ester and 10.0 g (0.043 mole) of O-phenylmethoxy-N,N'-diisopropylisourea (L. J. Mathias, Synthesis, 561 (1979)) in 200 ml of acetonitrile is stirred at reflux under a nitrogen atmosphere for 22 hours. The mixture is cooled and filtered to remove by-product 1,3-diisopropylurea. The insoluble material is washed with hexane and the combined filtrates are evaporated (vacuum). The residue is treated with 250 ml of diethyl ether, and the mixture is again filtered and evaporated. The crude oil residue is chromatographed over silica gel using dichloromethane/hexane (2:1) elution to obtain 7.2 g 64% yield) of the purified 5-methoxy-3-(phenylmethoxy)2-benzofurancarboxylic acid, methyl ester as an oil. The ester is saponified without additional purification.

Provenance & Evidence