One‐Pot Synthesis of Spiropyrans

Abstract A highly efficient one‐pot synthetic strategy for the preparation of spiropyrans was developed. The method is free of special equipment and operations, and meanwhile, it is energy‐ and time‐saving compared to the reported three‐step procedures. Tolerated with various solvents, bases, aldehydes, and alkyl bromides, the commonly used “T‐type” spiropyrans ( SP1 s) were synthesized in one‐pot with highly improved yields. To avoid the hydrolysis of the spiropyran moiety during the synthesis of the linear type spiropyrans ( SP2 s), a strategy of the combination of pre‐alkylation of phenolic hydroxyl group of 5‐hydroxy‐indole and a one‐pot synthesis of the spiropyran moiety was also designed. With a short reaction time, simplified workups, and reduced chemical waste, this one‐pot synthetic strategy for the synthesis of spiropyran compounds would facilitate related research in the fields of biology and materials science, and would be attractive to the industrial application.