Synthesis of some sulfur-containing spiro-pyrimidinetriones, pyrazolidinediones, and isoxazolidinediones

Novel sulfur‐containing spiro compounds such as 7,11‐diaryl‐9‐thia‐2,4‐diazaspiro [5,5] undecane‐1,3,5‐trione 9,9‐dioxides (2), 6,10‐diaryl‐8‐thia‐2,3‐diazas‐piro[4,5]decane‐1,4‐dione‐8,8‐dioxides (3) and 6,10‐diaryl‐2‐oxo‐8‐thia‐3‐azaspiro [4,5] decane‐1,4‐dione‐8,8‐dioxides (5) have been prepared by the condensation of 4‐dimethoxycarbonyl/diethoxycarbonyl‐3,5‐diaryl‐1‐thiane 1,1‐dioxides (1) with urea, hydrazine hydrate, and hydroxylamine hydrochloride, respectively. The N‐substituted derivatives (4 and 6) of 3 and 5 have also been prepared by acylation and nitrosation. The structures of 2, 3, and 5 were established by IR, 1H NMR, and 13C NMR spectral studies, respectively.