Studies on pesticides based on coumarin. IV. Synthesis and antifungal activity of twelve 4-(substituted phenoxy)methyl-6-methyl coumarins

Twelve 4‐(substituted phenoxy)methyl‐6‐methyl coumarins were synthesised by the condensation of 4‐chloromethyl‐6‐methyl coumarin with various phenols in the presence of potassium carbonate in dry acetone. The compounds were tested for their toxicity towards the mycelial growth of seven plant pathogenic fungi. Among the tested fungi, Pythium aphanidermatum, Colletotrichum falcatum, Drechslera oryzae, Alternaria alternata and Fusarium solani exhibited maximum sensitivity whereas Macrophomina phaseolina and Rhizoctonia solani were least sensitive to the test compounds. The 4‐(4‐tert‐butylphenoxy)methyl and 4‐(4‐nitrophenoxy)methyl analogues possessed greatest toxicity towards the majority of the tested fungi.