Solid phase synthesis of 2-aminobenzothiazoles

Abstract

A traceless solid supported protocol for the synthesis of 2-aminobenzothiazoles is described, employing resin-bound acyl-isothiocyanate and a series of anilines. Cyclization of the resulting Nacyl, N′-phenyl-thioureas generates the 2-aminobenzothiazole scaffold, which can be further elaborated prior to hydrazine-mediated cleavage of the final products from the carboxy-polystyrene resin. A small, focused library of 2-aminobenzothiazoles was prepared.

Reactivity and diverse synthetic applications of acyl isothiocyanates

“…41 The resin-bound isothiocyanate 59, prepared from the carboxy-polystyrene in two steps, got readily transformed to the corresponding thioureas 60 on treatment with anilines at room temperature. The cyclization of 60 to 2-acylaminobenzothiazole 61 was performed by treatment with six equivalents of bromine in acetic acid (Method A when X = H)).…”

Synthesis, Biological Activity and Recent Advancement of Benzothiazoles: A Classical Review

“…Compounds with pyrazoline and thiazole substitution were tending to have moderate anticancer activity. [2,14,15,19] Heterocyclic rings, 1-acetyl-pyrazoline and thiazole do not support eminently for anticancer activity. Chloro substituted amino benzothiazoles were found to have encouraging sensitivity to cancer cell lines compared to fluro substituted benzothiazoles.…”

“…They are widely found in bioorganic and medicinal chemistry with application in drug discovery. [2] Benzothiazole is a privileged bicyclic ring system with multiple applications. They show numerous biological activities such as antimicrobial [3][4][5][6][7] , anticancer [8][9][10][11] , anthelmintic [12] , and anti-diabetic activities.…”

An Aerobic Oxidative Coupling Approach for The Synthesis of N-Substituted 2-Aminobenzothiazole Derivatives using Iron Catalyst

“…Other methods of synthesising aminobenzothiazoles is by Herz method 10 , solid phase synthesis 11 , using benzyltrimethylammonium tribromide 12 or sodium dichloroiodate 13 , starting from o-nitroaniline 14 or in water 15 . Apart from synthesis, following biological activities were reported: Aurora-A kinase inhibitor 16 , calcium channel blockers 17 ,…”