A convenient, rapid, and one-pot method for the synthesis of azo dyes has been developed. In this protocol, diazotization reagent (ArN2+ -CrO3–SiO2) was prepared via grinding of aromatic amines, NaNO2, wet SiO2 and nano silica chromic acid (Nano-SCA) without solvent at room temperature. The obtained diazotization reagent was sufficiently stable to be kept at room […]