One-pot easy conversion of Baylis-Hillman adducts into the pyrazolidin-3-ones via trimethylsilyl iodide and hydrazine hydrate

An easy, one-pot transformation of Baylis-Hillman adducts into alpha,beta-unsaturated pyrazolidin-3-ones via reaction with trimethylsilyl iodide and hydrazine hydrate in the presence of catalytic amount of iodine is described. The mild reaction conditions, excellent yields and easy work-up procedures, makes it a useful alternative to previously applied procedures for the rapid synthesis of pyrazolidin-3-ones from easily available Baylis-Hillman adducts.