Synthesis and fungicidal activity of ethaboxam against Oomycetes

Abstract This study describes the chemical synthesis and intrinsic fungicidal activity of ethaboxam [ (RS) ‐ N ‐(α‐cyano‐2‐thenyl)‐4‐ethyl‐2‐(ethylamino)‐1,3‐thiazole‐5‐carboxamide], a new Oomycetes fungicide. In in vitro tests, ethaboxam showed inhibitory activity against isolates of Phytophthora and some Pythium spp, with MIC values ranging from 0.1 to 0.5 mg litre −1 for nine isolates of Phytophthora infestans (Montagne) de Bary and from 1.0 to 5.0 mg litre −1 for eight isolates of Phytophthora capsici Leonian. In tests to determine time and concentration for complete inactivation of each pathogen (five isolates of P infestans and five isolates of P capsici ), ethaboxam inactivated all isolates of P infestans within 48 h at 10 mg litre −1 and those of P capsici within 96 h at 10 mg litre −1 . Ethaboxam effectively suppressed development of tomato late blight caused by P infestans and pepper Phytophthora blight caused by P capsici in the studies conducted to determine its preventive, curative, persistent and systemic activity. These results show that ethaboxam has desirable fungicidal characteristics as an Oomycetes fungicide. Copyright © 2004 Society of Chemical Industry