AN AgOAc-CATALYZED REACTION OF 3-NITRO-2<i>H</i>-CHROMENES WITH ETHYL DIAZOACETATE: AN EFFICIENT ONE-POT SYNTHESIS OF ETHYL 3,4-DIHYDROCHROMENO[3,4-<i>c</i>]PYRAZOLE-1-CARBOXYLATES
DOI:
https://doi.org/10.1007/7001Keywords:
chromeno[3, 4-c]pyrazoles, ethyl diazoacetate, 3-nitro-2H-chromenes, 1, 3-dipolar cycloadditionAbstract
A regioselective method for the synthesis of ethyl 3,4-dihydrochromeno[3,4-c]pyrazole-1-carboxylates from 2-substituted 3-nitro-2H-chromenes and ethyl diazoacetate in 68–87% yields was developed. This approach involves an AgOAc-catalyzed 1,3-dipolar cycloaddition of ethyl diazoacetate to nitrochromenes followed by elimination of HNO2 by the action of DBU.
Authors: Lyudmila S. Bykova, Ivan А. Kochnev*, Alexey Yu. Barkov, Nikolay S. Zimnitskiy, Vladislav Yu. Korotaev*, Vyacheslav Ya. Sosnovskikh