Reaction of substituted 1,2,8,9-tetraazadispiro[4.1.4.3]tetradeca-1,8-dien-6-ones and 1,2,8,9-tetraazadispiro[4.1.4.2]trideca-1,8-dien-6-ones with chlorine

Reaction of 4,11-diaryl-1,2,8,9-tetraazadispiro[4.1.4.3]tetradeca-1,8-dien-6-ones and-dispiro[4.1.4.2]trideca-1,8-dien-6-ones with chlorine gives substituted dispirocyclic compounds containing a 3-chloro-1-pyrazoline fragment which loses nitrogen on heating to give spirocyclic chlorocyclopropanes.