Jiří Verner

Criss-cross Cycloadditions on Ketazines Derived from Alicyclic Ketones

The reactivity of alicyclic ketazines in criss-cross cycloadditions was investigated. They react with potassium cyanate and ammonium thiocyanate in the presence of acetic acid to form spirocyclic perhydro[1,2,4]triazolo[1,2-alpha][1,2,4]triazole-1,5-diones and perhydro[1,2,4]triazolo[1,2-alpha][1,2,4]triazole-1,5-dithiones, respectively, in relatively high yields.

A new route to 1,4-disubstituted 5-thioxoperhydroimidazo[4,5-d]imidazol-2-ones

1,4-Disubstituted 5-thioxoperhydroimidazo[4,5-d]imidazol-2-ones were prepared by one-pot criss-cross cycloaddition reactions of 1,4-disubstituted 1,4-diazabuta-1,3-dienes with HNCS and HNCO generated in situ from potassium salts by acetic acid.

Aromatic glyoxalimines in criss-cross cycloaddition reactions

Aromatic 1,4-diazabuta-1,3-dienes in glacial acetic acid with thiocyanates produce via criss-cross cycloaddition reactions the corresponding perhydroimidazo[4,5-d]imidazole-2,5-dithiones. When a mixture of thiocyanate and cyanate in a proper ratio was reacted together, nonsymmetrical 5-thioxo-perhydroimidazo[4,5-d]imidazole-2-ones were isolated. With cyanates substituted aromatic 1,4-diazabuta-1,3-dienes afforded product of acetic acid addition to primary formed 1,3-dipole intermediate 5-(4-substituted phenylamino)-3-(4-substituted phenyl)-2-oxoimidazolidin-4-yl acetate.