A nano-organo catalyzed route towards the efficient synthesis of benzo[b]pyran derivatives under ultrasonic irradiationElectronic supplementary information (ESI) available. CCDC 1477443, 1477627 and 1477628. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6ra24108e

• Main Authors: Nongrum, Ridaphun, Nongthombam, Geetmani Singh, Kharkongor, Mattilang, Star Rani, Jims World, Rahman, Noimur, Kathing, Chingrishon, Myrboh, Bekington, Nongkhlaw, Rishanlang
• Format: Article
• Language: English
• ISSN: 2046-2069
• DOI: 10.1039/c6ra24108e

An efficient, one-pot synthesis of benzo[ b ]pyrans catalyzed by vitamin B 1 functionalized Fe 2 O 3 @SiO 2 NPs under ultrasonic conditions is reported herein. The nano-organocatalyst was synthesized and characterized by FT-IR, TEM, EDS, powder XRD, etc. Several benzo[ b ]pyran derivatives were prepared with satisfactory yields and the nanocatalyst was magnetically retrieved and recycled. The salient features of this protocol include convenient work-up procedure, mild reaction conditions, easy catalyst recovery, shorter reaction time and use of green solvents. Ultrasound energy has been meticulously exploited for the synthesis of a nano-organocatalyst as well as for the preparation of several benzo[ b ]pyran derivatives. The biological activity of the synthesized benzo[ b ]pyrans were investigated and one of the derivatives was found to demonstrate profound activity in suppressing the side-effects of chlorpyrifos, an insecticide on the morphology of the external gills of the Duttaphrynus melanostictus tadpoles. Organocatalyst crafted on silica supported ferrite nanoparticle (Fe 2 O 3 @SiO 2 @VB 1 ) for 4 H -benzo[ b ]pyrans synthesis.