Reactions of Substituted Ethyl 1,2,3,4,4′,5′-Hexahydrospiro-[naphthalene-2,5′-pyrazole]-3′-carboxylates with Halogens
Substituted ethyl 1,2,3,4,4′,5′-hexahydrospiro[naphthalene-2,5′-pyrazole]-3′-carboxylates react with chlorine or N-bromosuccinimide to give spirocyclic substituted 3-halo-4,5-dihydro-3H-pyrazoles which lose nitrogen molecule on heating with formation of substituted spirocyclic 1-halocyclopropane-1-carboxylates. Heating of the title compounds with bromine in acetic acid results in opening of the spiro-fused six-membered ring to afford ethyl 4-aryl-5-[2-(2-carboxyphenyl)ethyl]pyrazole-3-carboxylates.
Unable to display preview. Download preview PDF.
- 2.Molchanov, A.P., Stepakov, A.V., Kostikov, R.R., and Baird, M.S., Synlett, 2000, p. 219.Google Scholar