SYNTHESES AND ANTIFUNGAL ACTIVITY OF DL-GRISEOFULVIN AND ITS CONGENERS .2.

Griseofulvin derivatives, dl-6'-demethyl-6'-ethylgriseofulvin (dl-5) a nd dl-6'-demethyl-6'-phenylgriseofulvin (dl-6) were prepared by applic ation of a synthetic method developed by us, Antifungal activity of th ese derivatives decreased in the order of dl-griseofulvin (dl-l) > dl- 5 much greater than dl-6 (inactive), The reaction of these derivatives with ethanethiol gave two types of compounds, 2'-(ethylthio)griseoful vin (15) and 4'-(ethylthio)isogriseofulvin (16). The relationship betw een the ratios of isolated yield of 15 and 16 and antifungal the activ ity of griseofulvin derivatives is discussed.