Cobalt(II) complexes based on (1-methyl-1H-benzo[d]imidazol-2-yl) methanol derivative: synthesis, crystal structure, spectroscopy, DFT calculations, and antioxidant activity

Sustainable Synthesis of 2-Hydroxymethylbenzimidazoles using D-Fructose as a C2 Synthon

D-fructose, a biomass-derived carbohydrate has been identified as an environmentally benign C₂ synthon in the preparation of synthetically useful 2-hydroxymethylbenzimidazole derivatives by coupling with 1,2-phenylenediamines. Proof of concept was established by synthesizing 23 examples using BF₃ .OEt₂ (20 mol%), TBHP (5.5 M, decane) (1.0 equiv.) in CH₃ CN at 90 °C for 1 h. The pivotal features of this method include metal-free conditions, short time, good functional group tolerance, gram scale feasibility and the synthesis of benzimidazole fused 1,4-oxazine. Control studies with conventional C₂ synthons did not produce the desired product, thus suggesting a new reaction pathway from D-fructose.