FeCl<sub>3</sub>/Ultrasound Mediated Reaction of 2-aminothiophenol with Aldehydes in Water: Synthesis of 2-substituted Benzothiazoles of Pharmacological Interest

We report a FeCl3•6H2O mediated green and rapid access to benzothiazole derivatives having a substituent at C-2 via the condensation of 2-aminothiophenol with various aldehydes under ultrasound irradiation and air. The reaction progressed well in water affording the expected products in good yields. Two of these compounds known to be potent anticancer agents showed good interactions with PDE4B in silico and inhibited this enzyme when tested in vitro. Keywords: Benzothiazole, FeCl3, ultrasound, water, PDE4.