Synthesis of 4-substituted ethers of benzophenone and their antileishmanial activities

Leishmaniasis is a vector-borne protozoan disease; it mainly originates from the bite of sandfly and initiated when parasite is transmitted to human at metacyclic flagellated promastigote form. In the current study, a synthesis of a series of 4-substituted benzophenone ethers 1-20 was carried out in good yields and their in vitro antileishmanial activities were also screened. Among synthetic derivatives, 15 compounds 1, 3, 5-12, 15 and 17-20 showed antileishmanial activities against promastigotes of Leishmania major with IC₅₀ values in the range of 1.19-82.30 µg ml^-1, and the values were compared with those of the standard pentamidine (IC₅₀= 5.09 ± 0.09 µg ml^-1). Our study identified a series of new antileishmanial molecules as potential leads. Structures of these synthetic compounds were deduced by different spectroscopic techniques, such as ¹H and ¹³C nuclear magnetic resonance, electron impact and high-resolution electron impact mass spectrometry and IR.