Synthesis of 7-14Cbergapten

摘要

Bergapten (1) is a furocoumarin natural product and currently employed to treat skin disorders. Since past attempts to radiolabel 1 with 14C were limited to only its 5-methoxy group, a synthesis of the required ring 7-14C1 is now described. The literature reported precursor 4-methoxy-6-hydroxybenzofuran-5-carboxaldehyde (3) was Wittig reacted with stabilized carbonyl-14Cmethoxycarbonylmethylenetriphenylphosphorane (4) to obtain 7-14C1 in 47 radiochemical yield, with the desired product being characterized by thin-layer chromatography, HPLC, m.p. and proton NMR.