Synthesis and uncoupling activities of hydrophobic thioureas.

Abstract

Various N-aryl-N'-phenylthioureas, N, N'-diarylthioureas and N-(1, 2, 4-triazol-3-yl)-N'-arylthioureas were prepared and examined for uncoupling activities. The results indicate that substitution at the 4-position of the phenyl groups of diaryl thioureas is very important for uncoupling activities. Diphenyl thioureas substituted with two or more halogen atoms exhibited strong activities. The highest activity was exhibited by a compound containing nitro groups on both phenyl groups. These results indicate that the hydrophobicity and acidic nature of the compound are of primary importance for uncoupling activities. A remarkable decrease in activity was observed with the thioureas which were substituted with pyridine and 1, 2, 4-triazole rings. The reaction of phenyl isothiocyanate with 3-amino-1, 2, 4-triazole was also studied.