Reactions of Substituted Ethyl 1,2,3,4,4′,5′-Hexahydrospiro-[naphthalene-2,5′-pyrazole]-3′-carboxylates with Halogens
作者:A. P. Molchanov、V. S. Korotkov、J. Kopf、R. R. Kostikov
DOI:10.1007/s11178-005-0289-5
日期:2005.7
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.
取代的 1,2,3,4,4′,5′-六氢螺[萘-2,5′-吡唑]-3′-羧酸乙酯与氯或 N-溴代琥珀酰亚胺反应生成取代的螺环 3-卤-4、5-二氢-3H-吡唑,加热时失去氮分子,形成取代的螺环 1-卤代环丙烷-1-羧酸盐。将标题化合物与溴在乙酸中加热,可打开螺融六元环,得到 4-芳基-5-[2-(2-羧基苯基)乙基]吡唑-3-羧酸乙酯。