An Unusual Cyclization of Trifluoroacetohydroximoyl and -hydrazonoyl Bromides with Malononitrile
作者:Kiyoshi Tanaka、Takashi Suzuki、Seiji Maeno、Keiryo Mitsuhashi
DOI:10.1246/bcsj.60.4480
日期:1987.12
Trifluoroacetohydroximoyl bromide etherate (1) reacted with an excess of malononitrile in the presence of sodium methoxide, giving a fused isoxazolopyridine 3, participated by two molecules of malononitrile, along with the conventional isoxazole 2. Similar concomitant formation of 7 and the fused pyrazolopyridines 8 was also recognized from the hydrazonoyl bromides 6 and their product ratio was found to depend on the reaction conditions, particularly on the concentration of malononitrile used.
在甲醇钠存在下,三氟乙酰基溴羟亚甲酰醚(1)与过量的丙二腈反应,生成了由两分子丙二腈参与的融合异噁唑吡啶 3 和传统的异噁唑 2。从肼基溴化物 6 中也同样生成了 7 和融合的吡唑并吡啶 8,而且发现它们的产物比例取决于反应条件,特别是所用丙二腈的浓度。