Synthesis and bioactivity of N-cyclopropanecarboxyl-N′-pyridin-2-yl thiourea derivatives and related fused ring compounds

Cyclopropanecarboxylic acid or 2,2-dimethyl cyclopropanecarboxylic acid was used as a leading compound for its biological activity. Six new N-(substituted) cyclopropanecarboxyl-N′-pyridin-2-yl thioureas were prepared. Compound 5 was obtained by oxidizing cyclization of compound 4 in the presence of bromine in chloroform solution. The structures of 4 and 5 were confirmed by 1H NMR and elemental analysis. The preliminary biological tests indicate that compound 4b and 4e have excellent herbicidal activity, and compound 4c and 4f have excellent fungicidal activity.