Synthesis of novel pyrimidine derivatives with (pyridin-3-ylmethyl)thio and phenylamino moieties and evaluation of their antifungal activity

A series of novel pyrimidine derivatives with (pyridin-3-ylmethyl)thio and phenylamino moieties were synthesized from ethyl acetoacetate, thiourea, 3-pyridinylmethyl chloride hydrochloride, and substituted anilines by multi-step reactions. The structures of the target compounds were characterized by IR, ¹H NMR, ¹³C NMR and elemental analysis. The in vitro antifungal activities against Botrytis cinerea and Sclerotinia sclerotiorum were evaluated. The result showed that N-phenyl-6-methyl-2- ((pyridin-3-ylmethyl)thio) pyrimidin-4-amine (4a) displayed high inhibition activity against Botrytis cinerea with 87.5%inhibition at 100 µg/mL; 4a, and N-(4-isopropylphenyl)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin-4-amine (4c), N-(4-methoxyphenyl)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin-4-amine (4d) and N-(2-hydroxy-5-chloro)-6-methyl-2-((pyridin-3-ylmethyl)thio)pyrimidin- 4-amine (4h) exhibited sufficient activities against Sclerotinia sclerotiorum with 86.6% –93.7% inhibitions at the same concentration.