Synthesis of Imidazo[1,2‐a]pyridines: C‐H Functionalization in the Direction of C‐S Bond Formation

Imidazo[1,2‐a]pyridines play an important role in medicinal chemistry. In spite of very drastic developments on syntheses and functionalization in this area, the use of inexpensive catalysts and mild reaction conditions constitutes an important role in pharmaceutical applications. This account describes our recent efforts on the development of new methods for the synthesis of imidazo[1,2‐a]pyridines using readily available starting substrates and catalysts under very mild reaction conditions. In the direction of enhancement of biological activity, we also described the synthesis of functionalized imidazo [1,2‐a]pyridine derivatives.     

Spectrophotometric estimation of bromide ion in excess chloride media

The redox reaction between bromate and chloride ions in the presence and the absence of two or less equivalents of bromide ion ascertaining the formation of bromine chloride species of type BrCl and BrCl₂⁻ in subsequent reactions in 4% H₂SO₄, has been studied by spectrophotometry. Calibration graphs for the bromide ion estimation in 0.1% KBrO₃–4% H₂SO₄ medium are determined separately in the presence of known amounts of NaCl. The effect of Cl⁻ ion percentage on the determination of Br⁻ ion is studied and reported herewith a suitable equation for a precise, reliable and quick spectrophotometric estimation.     

A novel application of Hβ-zeolite in catalytic dehalogenation of halophenols

A new application of Hβ-zeolite for debromination of bromophenols and deiodination of iodophenols is presented in this note. The heterogeneous catalyst can be recovered and recycled effectively for subsequent reactions. The catalyst was found ineffective for similar action on chlorophenols.     

A new, environment friendly protocol for iodination of electron-rich aromatic compounds

A new environment friendly procedure for effective aromatic iodination is presented. A mixture of potassium iodide and potassium iodate is used in the presence of an acid for in situ iodination of aromatic compounds.