In reaction of 4’-arylspiro[1,2,3,4-tetrahydronaphthalene-2,3’-(1’- pyrazolin)]-1-ones with N-chlorosuccinimide formed spirocyclic substituted 3-chloro-1-pyrazolines that lost nitrogen at heating transforming into spirocyclic chlorocyclopropanes. The reaction of the same pyrazolines with chlorine led to the formation of spirocyclic gem-dichlorocyclopropanes. © Nauka/Interperiodica 2006.