Two efficient syntheses of hloro-7-[(chlorocarbonyl)methoxy]-4-methylc
oumarin are described, one utilizing traditional chemistry starting fr
om 3-chloro-7-hydroxy-4-methylcoumarin, while the other uses a novel r
eagent, sulfuryl chloride/thionyl chloride, in a one-pot reaction star
ting from 7-(carboxymethoxy)-4-methylcoumarin.