Antifungal activity of naphthothiazoles derived from Lawsone (<i>Lawsonia inermis</i>)

Abstract

A series of Naphtho [2,3-d] thiazole-4, 9-diones was prepared by the condensation of bromolawsone with thiosemicarbazones derived from the aldehydes and ketones in dry dimethyl formamide (DMF). The products are also obtained by the cyclization of the intermediate 2-chlorobenzaldehyde thiosemicarbazone of 1,4-napthoquinone in ethanol containing K₂CO₃ obtained from 2,3-dichloro naphthoquinone. These compounds showed that maximum fungicidal activity varied with substituent on the compounds of Lawsone.

Key words: Lawsonia inermis, 2,3-dichloronaphthoquinones, thiosemicarbazones, naphthothiazoles, fungicidal activity, Fusarium oxysporum, Curvularia lunata.