4-Arylamino-6-nitroquinazolines: Synthesis and their activities against neglected disease leishmaniasis.

4-Arylamino-6-nitroquinazolines (2-25) were synthesized and evaluated for their leishmanicidal activities against Leishmania major promastigotes in vitro with IC50 values = 1.87-61.48 μM. Among the twenty four synthetic derivatives, 4-[4'-(methylsulfanyl)phenyl]amino-6-nitroquinazoline (21), and 4-(2'-methoxyphenyl)amino-6-nitroquinazoline (8) showed excellent antileishmanial activities with IC50 values 1.87 ± 0.31 and 4.37 ± 0.02 μM, respectively, more active than the standard drug, pentamidine (IC50 = 5.09 ± 0.09 μM). Compound 16 (IC50 = 6.53 ± 0.21 μM) displayed an activity comparable to the standard. Compounds 15 (IC50 = 9.04 ± 0.03 μM), 18 (IC50 = 12.28 ± 0.18 μM), 14 (IC50 = 19.87 ± 0.22 μM), and 5 (IC50 = 24.03 ± 2.71 μM) also showed good activities.