The synthesis of trialkylpyrazines having methyl groups on C-2 and C-5 is described, which is completed by the cross-coupling reaction of 2-chloro-3,6-dimethylpyrazine with dialkylzinc in the presence of [1,3-bis(diphenylphosphino)propane] nickel(II) chloride. Similarly, 2,5-diisobutyl-, -diisopropyl- and -di-sec-butyl-3-methylpyrazines are prepared from the corresponding dialkyl chloropyrazines. The dimethyl products are acylated with an α-keto acid under the Minisci radical conditions providing 2-acyl-5-alkyl-3,6-dimethylpyrazines. Several compounds obtained in this study prove to be active as components of pheromones in ants.
本文描述了具有C-2和C-5位甲基的三烷基
吡嗪的合成方法,该合成通过2-
氯-
3,6-二甲基吡嗪与二烷基
锌在[1,3-双(
二苯基膦基)
丙烷]
镍(II)
氯化物的催化下进行交叉耦合反应完成。类似地,从相应的二烷基
氯吡嗪制备了2,5-
二异丁基-、
二异丙基-和
二仲丁基-3-甲基
吡嗪。二甲基产物通过Minisci自由基条件下与α-
酮酸的酰化反应,得到了2-酰基-5-烷基-
3,6-二甲基吡嗪。本研究中得到的几种化合物证实作为蚂蚁信息素的组成部分具有活性。