Other Four-membered Rings containing Sulphur and Nitrogen

Hritzova and P. Kristian, Collect. Czech. Chem. Commun., 1978,43, 3258. 

Burger, R. Ottlinger, A. Proksch, and J. Firl, J. Chem. Soc., Chem. Commun., 1979, 80. 

Dimer (151) is opened and stabilized by pyridine and S4N4- Sulphur trioxide gives (152) with A -(sulphinyl)trifluoromethanesulphonamide. Both (151) and (152) react with benzonitrile to give (153). With aryl isocyanates, they give (154). Both 1,2,3,4-dithiadiazetidines and 1,3,2,4-dithiadiazetidines have been proposed - s reaction intermediates. 

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