A Novel Synthesis of 4-Pyridazineacetic Acids<i>via</i>Ring Expansion of<i>N</i>-Cyanomethylated 3-Pyrazoline-4-acetic Acids
作者:Eiichi Masumoto、Hiroshi Maruoka、Fumi Okabe、Sho Nishida、Ryoko Tomita、Toshihiro Fujioka、Kenji Yamagata
DOI:10.1002/jhet.894
日期:2012.7
A novel synthetic route to 4‐pyridazineacetic acids 10–12 has been achieved by the ring‐expansion reaction of N‐cyanomethylated 3‐pyrazoline‐4‐acetic acids 7–9. 1H‐Pyrazole‐4‐acetic acids 1–3 were reacted with iodoacetonitrile in the presence of triethylamine in refluxing acetonitrile to give the corresponding C‐cyanomethylated 1H‐pyrazole‐4‐acetic acids 4–6 as major products together with N‐cyanomethylated
到4- pyridazineacetic氨基酸的新的合成路线10 - 12已经通过的环扩大反应实现Ñ -cyanomethylated 3-吡唑啉-4-乙酸7 - 9。1 ħ吡唑-4-乙酸1 - 3用碘乙腈在三乙胺的存在下在回流的乙腈中,得到相应的反应Ç -cyanomethylated 1个ħ吡唑-4-乙酸4 - 6种作为主要产品连同ñ -氰甲基化3-吡唑啉-4-乙酸7和8作为次要产品。另一方面,在三乙胺存在下,在回流的氯仿中,1和3与氯乙腈的反应提供了相应的N-氰甲基甲基化3-吡唑啉-4-乙酸7和9作为主要产物。的热处理7 - 9与在氢化钠N,N-二甲基甲酰胺引起环扩展得到相应的4- pyridazineacetic氨基酸10 - 12。