Thiocarbonyl-imide aus der Umsetzung von 2,2,4,4-Tetramethyl-3-thioxocyclobutanon mit Aryl-aziden

Thiocarbonyl Imides from the Reaction of 2,2,4,4-Tetramethyl-3-thioxocylobutanone and Aryl Azides Reaction of 2,2,4,4-tetramethyl-3-thioxocylobutanone ( 6 ) and 4-methoxyphenyl, phenyl, and 4-nitrophenyl azide ( 7a–c , respectively), at 80°, leads to the 11-aryl-5,10-dithia-11-azadispiro[3.1.3.2]undecane-2,8-diones 8a–c (Scheme 3), respectively, in 67–83% yield. The structure of 8b has been established by X-ray crystallography. The formation of the products may be explained via an intermediate thiocarbonyl imide of type D (Scheme 4), generated by the 1,3-dipolar cycloaddition of the aryl azide with the C? S bond of 6 and elimination of N₂.