Aromatization of 1,3,5-Trisubstituted of 4,5-Dihydro-1H-Pyrazoles by In-Situ Generation of I+ from Hydrogen Peroxide/Acids/Iodide Potassium or Sodium Systems

A simple, green and cost-effective protocol was used for the aromatization of 1,3,5-trisubstituted-2-pyrazolines to the corresponding pyrazoles by in situ generation of iodine (I+) from H2O2/AcOH or SSA or oxalic acid /KI or NaI system under thermal condition with moderate to good yields.