Substituent-Driven Selective <i>N</i>-/<i>O</i>-Alkylation of 4-(Trihalomethyl)pyrimidin-2(1<i>H</i>)-ones Using Brominated Enones
作者:Mateus Mittersteiner、Genilson S. Pereira、Yuri Silva、Ludger A. Wessjohann、Helio G. Bonacorso、Marcos A. P. Martins、Nilo Zanatta
DOI:10.1021/acs.joc.1c02919
日期:2022.4.1
The selective N- or O-alkylation of 4-(trihalomethyl)pyrimidin-2(1H)-ones, using 5-bromo enones/enaminones as alkylating agents, is reported. It was found that the selectivity toward the N- or O-regioisomer is driven by the substituent present at the 6-position of the pyrimidine ring, thus enabling the preparation of each isomer as the sole product, in 60–95% yields. Subsequent cyclocondensation of
报道了使用 5-溴烯酮/烯胺酮作为烷基化剂对 4-(三卤甲基)嘧啶-2( 1H )-酮进行选择性N-或O-烷基化。发现对N - 或O - 区域异构体的选择性是由嘧啶环 6 位上存在的取代基驱动的,因此能够以 60-95% 的产率制备每种异构体作为唯一产物。随后烯胺酮部分与氮双亲核试剂的环缩合导致嘧啶-唑缀合物的产率为 55-83%。