Regioselective addition of Grignard reagents to <i>N</i>-acylpyrazinium salts: synthesis of substituted 1,2-dihydropyrazines and Δ<sup>5</sup>-2-oxopiperazines
作者:Valentine R St. Hilaire、William E Hopkins、Yenteeo S Miller、Srinivasa R Dandepally、Alfred L Williams
DOI:10.3762/bjoc.15.8
日期:——
The regioselective addition of Grignard reagents to mono- and disubstituted N-acylpyrazinium salts affording substituted 1,2-dihydropyrazines in modest to excellent yields (45-100%) is described. Under acidic conditions, these 1,2-dihydropyrazines can be converted to substituted Δ5-2-oxopiperazines providing a simple and efficient approach towards their preparation.
描述了格氏试剂向单取代和二取代的N-酰基吡嗪鎓盐的区域选择性加成,以适中至优异的产率(45-100%)提供了取代的1,2-二氢吡嗪。在酸性条件下,这些1,2-二氢吡嗪可被转化为取代的Δ5-2-氧代哌嗪,从而提供了一种简单有效的制备方法。