A Flexible Strategy for the Regiocontrolled Synthesis of Pyrazolo[1,5-<i>a</i>]pyrazines
作者:Peter J. Lindsay-Scott、Natalie G. Charlesworth、Alexandru Grozavu
DOI:10.1021/acs.joc.7b02128
日期:2017.10.20
four-step protocol for the synthesis of pyrazolo[1,5-a]pyrazines has been developed. Commercially available pyrazoles were alkylated and formylated in a regiocontrolled manner to give pyrazole-5-aldehydes bearing 2,2-dialkoxyethyl substitution on N-1. Efficient conditions for the subsequent deprotection and cyclization of these intermediates allowed access to pyrazolo[1,5-a]pyrazines with multiple substitution
已经开发了用于合成吡唑并[1,5- a ]吡嗪的四步方案。将可商购的吡唑以区域控制的方式烷基化和甲酰化,得到在N -1上带有2,2-二烷氧基乙基取代的吡唑-5-醛。这些中间体随后的脱保护和环化的有效条件允许获得具有多个取代模式的吡唑并[1,5- a ]吡嗪。通过脱保护和双还原胺化序列进一步证明了吡唑-5-醛中间体的多功能性,得到4,5,6,7-四氢吡唑并[1,5- a ]吡嗪。