Synthesis of biologically active angularly fused bisaroylbenzodifurans by PTC and solvent free microwave irradiation

Abstract

Angularly fused bisaroylbenzodifurans <b>3a-f</b> have been synthesized by condensing 2,4-diacetyl resorcinol <b>1</b> with various <i>p-</i>substituted phenacyl bromides <b>2a-f</b> under (a) phase transfer catalysis method and (b) microwave irradiation method. A comparison has been made between the two methods. Microwave irradiation has been found to be an efficient route for the synthesis of angularly fused bisaroylbenzodifurans. All the compounds <b>3a-f</b>

have been screened for anti-bacterial activity. The benzodifurans <b>3c</b> and <b>3f</b> have shown excellent activity against gram-positive (<i>Staphylococcus aureus</i>)<i> </i>bacteria at both 600 and 900 μg/mL and the compound <b>3b</b> and <b>3d </b>are found active at 900 μg/mL on the same bacteia. The bisaroylbenzodifurans <b>3a-f</b> have also been screened for anti-fungal activity. The compounds <b>3c</b>, <b>3d</b> and <b>3f</b> have shown maximum spore germination inhibition on <i>Drechslera halodes </i>fungi and the compounds <b>3a</b>, <b>3b</b>, <b>3c</b>, <b>3d</b>, and <b>3f</b> have shown maximum spore germination inhibition on <i>Fusarium</i> <i>oxysporum </i>fungi at 960μg/mL. The bisaroylbenzodifurans <b>3a</b> and <b>3e</b> have been screened for anti-implantation activity as well and found to be inactive at 10 mg/kg/rat/day.