Brominated Trihalomethylenones as Versatile Precursors to 3-Ethoxy, -Formyl, -Azidomethyl, -Triazolyl, and 3-Aminomethyl Pyrazoles
作者:Marcos A. P. Martins、Adilson P. Sinhorin、Clarissa P. Frizzo、Lilian Buriol、Elisandra Scapin、Nilo Zanatta、Helio G. Bonacorso
DOI:10.1002/jhet.996
日期:2013.1
‐pyrazoles from a cyclocondensation reaction with hydrazine monohydrate in ethanol. 3‐Ethoxymethyl‐carboxyethyl ester pyrazoles were formed as a result of a substitution reaction of bromine and chlorine by ethanol. The dibrominated precursor furnished 3‐acetal‐pyrazole that was easily hydrolyzed to formyl group. In addition, brominated precursors were used in a nucleophilic substitution reaction with
研究了5-溴[5,5-二溴] -1,1,1-三卤代-4-甲氧基-3-戊烯[己烯] -2-酮是合成3-乙氧基甲基-5-三氟甲基-1的前体。在乙醇中与一水合肼发生环缩合反应生成的H-吡唑类化合物。3-乙氧基甲基-羧乙基酯吡唑是由于溴和氯被乙醇取代而形成的。二溴化的前体提供了3-乙缩醛-吡唑,它很容易水解为甲酰基。此外,溴化前体与叠氮化钠用于亲核取代反应,以合成3-叠氮基甲基-5-乙氧基羰基-1 H吡唑与一水合肼反应。这些产物与苯基乙炔进行环加成反应,得到3- [4(5)-苯基-1,2,3-三唑基] 5-乙氧基羰基-1H-吡唑,并经过还原反应生成3-氨基甲基-1 H-吡唑-5-羧乙基酯。通过简单的方法获得产物,产率中等至良好。