Synthesis and biological evaluation of 4,7,9-trisubstituted benzoxazepines as antileishmanial agents

Herein we report a series of antileishmanial analogues derived from 4-[(3,5-dimethyl-4-isoxazolyl)acetyl]-9-[(1methyl-3-piperidinyl)methoxy]-7-(5-methyl-2-thienyl)-2,3,4,5-tetrahydro-1,4-benzoxazepine (1), which was identified through a previously reported high-throughput phenotypic screen. The analogue series was designed, synthesized, and evaluated for antileishmanial activity to establish pharmacophore elements and preliminary structure-activity relationships as key steps in validating the series for further optimization. This study led to identification of the early lead compound 46 , which exhibited sub-micromolar proliferation inhibitory activity against intra-macrophage L. mexicana amastigotes, modest selectivity towards host macrophages (J774A.1 line), and good aqueous solubility.