New Efficient Synthesis of 2-Thioxo-2,3-dihydropyrimidin-4(1H)-ones from Baylis–Hillman Adducts

Azides obtained from Baylis-Hillman adducts were treated with triphenylphosphine to give the corresponding iminophosphoranes, which reacted with carbon disulfide at 40 degrees C to produce isothiocyanates. The reaction of these isothiocyanates with primary amines provided thiourea intermediates, which in the presence of potassium carbonate or sodium methoxide were converted into 2-thioxo-2,3-dihydropyrimidin-4(1H)-ones in good yields.