Synthesis and antibacterial screening of <i style="">N</i>-[Naphtho[1,2-<i>b</i>]pyrano[3,4-<i>d</i>]thiazol-8-yl] spiroindoloazetidin-2-ones/thiazolidin-4-ones

Abstract

2-Amino-11-hydronaphtho[2,1:5,6]pyrano[4,3-<i style="">d</i>]thiazole <b style="">1a-d</b> on treatment with isatin affords naphtho[1,2-<i style="">b</i>]pyrano[3,4-<i style="">d</i>]thiazolo-8-yl(3-imino-2-oxo-1<i>H</i>-indole <b style="">2a-d</b> which on further reaction with chloroacetyl chloride and mercaptoacetic acid yields the corresponding <i style="">N</i>-[naphtho[1,2-<i style="">b</i>]pyrano[3,4-<i style="">d</i>]thiazol-8-yl]spiro-[3<i style="">H</i>-indole-(1<i style="">H</i>,2<i style="">H</i>)-3,4-(2<i style="">H</i>)-3-chloroazetidin-2,2-diones <b style="">3a-d</b> and <i style="">N</i>-[naphtho[1,2-<i style="">b</i>]pyrano[3,4-<i style="">d</i>]thiazol-8-yl]spiro-[3<i style="">H</i>-indole-(1<i style="">H</i>,2<i style="">H</i>)-3,2-(4<i style="">H</i>)-thiazolidine]-2,4-dione <b style="">4a-d</b>. All the compounds <b style="">2a-d</b>, <b style="">3a-d</b> and <b style="">4a-d</b> have been screened and found to possess considerable antibacterial activity.