One-Pot, Borax-mediated synthesis of structurally diverse N, S-heterocycles in water

Herein, a borax-mediated convenient and efficient strategy for the synthesis of prominent structurally diverse N, S-heterocycles such as quinazolin-4(3H)-one, benzothiadiazine 1,1-dioxide, benzothioazole, and benzoxazoles from readily available 2-aminobenzamide/2-aminobenzenesulfonamide/2-aminothiophenol/2-aminophenol with alpha,alpha,alpha-trihalotoluenes at 100 degrees C in water is elaborated. Upon using aldehydes instead of alpha,alpha,alpha-trihalotoluenes, the reactions proceed through domino fashion under the catalytic effect borax to yield 2,3-dihydroquinazolin-4(1H)-one, 3,4-dihydrothiadiazine 1,1-dioxide, and benzothiazoles in one-pot at 60 degrees C The advantages of this protocol are practical simplicity, large substrate scope, moderate to excellent yields, and the use of water as the solvent. (C) 2021 Elsevier Ltd. All rights reserved.