Sodium alginate: Biopolymeric catalyst for the synthesis of 2-amino-4-arylthiazole derivatives in aqueous medium

•A new method was described for the synthesis of 2-amino-4-arylthiazole derivatives with alginate as a catalyst.•Alginate has hydrophilic structure that can be use in aqueous medium and eco-friendly condition.•The reagent for this route is TBBDA as a bromine source with easy purification of products and good yields in shorter time than other works.•In this protocol, we synthesized different derivatives of 2-amino-4-arylthiazoles with electron-donating and electron-withdrawing groups. [Display omitted] Regarded as a naturally occurring macromolecule and without any post-modification, sodium alginate which possesses a granular form was found to be an efficient and recoverable bifunctional heterogeneous organocatalyst for the synthesis of 2-amino-4-arylthiazole derivatives was carried out by the reaction of substituted phenyl acetylene and thiourea in an eco-friendly condition in the presence of TBBDA (tetrabromobenzene-1,3-disulfonamide (tetrabromobenzene-1,3-disulfonamide). Mild reaction conditions, simple reaction procedure, easy purification, high yields of products, eco-friendly catalyst usage and convenient reusability are the highlighted points of this protocol.