General procedure for the synthesis of 2-(4-hydroxy-3-methoxyphenyl)benzothiazole from vanillin and 2-aminobenzenethiol: In a catalytic reaction, a mixture of vanillin (3 mmol), 2-aminobenzenethiol (3 mmol) and CdS nanorods (5 mg) was placed in a 100 mL double-walled quartz flask equipped with a water inlet and outlet to maintain the reaction temperature at room temperature. The reaction was carried out in methanol (20 mL) and the reaction mixture was exposed to visible light for the indicated time under stirring conditions (see Table 3). The progress of the reaction was monitored by thin layer chromatography (TLC) and gas chromatography (GC). Upon completion of the reaction, methanol was removed by rotary evaporation and the residue was dissolved in dichloromethane. The catalyst was separated from the reaction mixture by centrifugation. Subsequently, the dichloromethane was evaporated to dryness and the product was purified by silica gel G60 column chromatography.
