5-Aryl-1,3,4-oxathiazol-2-one was prepared from the reaction of benzamide with chlorocarbonylsulfenyl chloride. The reactions of the various oxathiazolones with triethyl phosphite resulted in the formation of the corresponding benzonitrile and ethyl phosphorothioate in 66-94% yields. 5-(Nitrophenyl)-1,3,4-oxathiazol-2-one was reacted also with trimethyl phosphite, triethyl phosphine, and triphenyl phosphine to give 4-nitrobenzonitrile. But it gave no reaction with triphenyl phosphite.
5-Aryl-1,2,4-dithiazol-3-one was prepared from the reaction of thiobenzamide with chlorocarbonylsulfenyl chloride. The thiobenzamide was prepared from the reaction of benzamide with phosphorus pentasulfide in pyridine. The reaction of 5-(4-bromophenyl)-1,2,4-dithiazol-3-one with triphenyl phosphine resulted in the formation of 4-bromothiobenzoyl isocyanate and triphenyl phosphine thioxide. The fragmentation of thioacyl isocyanate to nitrile and the 1,4-cycloaddition of the thioacyl isocyanate with benzalaniline were investigated.
In each case of the reactions, desulfurization by trivalent phosphorus compound was observed, and the plausible mechanism of the desulfurization, intramolecular rearrangement after insertion of the phosphorus atom into the ring was suggested.
1,4-Cycloaddition of the thioacyl isocyanate with imine gave a new compound, thiadiazinone and its structure was characterized by IR and $^1H$ NMR spectrometry.
5-아릴-1,3,4-옥사티아졸-2-온을 트리에틸포스파이트와 반응시키면 벤조니트릴과 에틸 포스포로티오에이트가 66~94% 수율로 얻어진다. 다른 3가의 인 화합물 즉, 트리메틸포스파이트, 트리에틸포스핀, 그리고 트리페닐포스핀들과도 같은 반응이 관찰된다. 그러나 트리페닐포스파이트와는 전혀 반응하지 않았다.
5-아릴-1,2,4-디티아졸-3-온을 트리페닐포스핀과 반응시키면 티오아실 이소시아네이트가 얻어진다. 이것은 에테르에서 자체적으로 분해되어 벤조니트릴로 변하게 되나 클로로포름에서는 안정하다.
이 두 반응에서 관찰되는 탈황반응은 인이 고리속으로 들어가 고리를 늘인 후 분자내에서의 자리옮김반응에 의해 일어나는 것이라 기대된다.
클로로포름에서 안정한 티오아실 이소시아네이트를 이민과 1,4-고리화 첨가반응을 시켜 티아다이아지논을 합성하였다.
