Synthesis and antifungal activities of 4-[5-(2-cyclopropylamino- pyrimidin-4-yl)-4-arylthiazol-5-yl]piperidine derivatives on Phytophthora capsici

Fungicidal activities against phytopathogenic fungi of diarylthiazole compound of 4-[5-(2-cyclopropylaminopyrimidin- 4-yl)-4-(4-fluorophenyl)thiazol-5-yl]-1-methylpiperidine (I) have been determined to be excellent and compound I was used as the leading compounds in this study. Furthermore, the compound was synthesized by reacting them with five functional groups, 4-fluoro-3-methylphenyl, 4-fluoro-3-chlorophenyl, 4-chloro-2-fluorophenyl, 4-bromo-3-methylphenyl and 2,4-dichlorophenyl groups instead of 4-fluorophenyl group. Also, 2-amino-, 2-(N- ethoxycarbonyl)piperidin-4-yl-, and 2-piperidin-4-yl-thiazole were introduced as the leads instead of 2-N- methylpiperidine-4-yl-thiazol of compound I. VIII-1~VIII-5 and XIII-1~XV-5 compounds were newly synthesized and their structures were confirmed by 1H-NMR-spectrum. The fungicidal activities of all the synthesized compounds against Phytophthora capsici were examined using the whole plant method. Among the VIII-1 ~VIII-5 and XIII-1~XV-5 chemicals, XIV-3 showed the most potent antifungal activity in vivo. While the EC50 and EC90 values of the commercial fungicide dimethomorph and I were 4.26±0.02, 14.72±0.05 and 1.01±0.11, 6.31±0.09 mM, those of 4-[5-(2-cyclopropylaminopyrimidin-4-yl)-4-(4-chloro-2-fluorophenyl)thiazol-5-yl]-1- methylpiperidine (XIV-3) was 0.98±0.21 and 5.85±0.05 mM. Therefore, XIV-3 can be considered as a viable candidate for the control of plant diseases caused by P. capsici, and further studies will be conducted on the mode of action XIV-3.