Catalytic action of azolium salts. I. Aroylation of 4-chloro-1H-pyrazolo(3,4-d)pyrimidines with aromatic aldehydes catalyzed by 1,3-dimethylbenzimidazolium iodide.
作者:Akira MIYASHITA、Hideaki MATSUDA、Chihoko IIJIMA、Takeo HIGASHINO
DOI:10.1248/cpb.38.1147
日期:——
When a mixture of 4-chloro-1-phenyl-1H-pyrazolo[3, 4-d]pyrimidine (9), aromatic aldehyde (5), sodium hydride, and a catalytic amount of 1, 3-dimethylbenzimidazolium iodide (4) in tetrahydrofuran was refluxed, the nucleophilic aroylation occurred, resulting in the formation of the aryl 1-phenyl-1H-pyrazolo[3, 4-d]pyrimidin-4-yl ketones (11).Similar reaction of 4-chloro-1-methyl-1H-pyrazolo[3, 4-d]pyrimidine (10) gave the corresponding aryl 1-methyl-1H-pyrazolo[3, 4-d]pyrimidin-4-yl ketones (12) in moderate yields. Use of dimethylformamide or dimethyl sulfoxide in the above reaction reduced the necessary reaction time and reaction temperature. A plausible reaction pathway for the formation of the ketones 11 and 12 involving the catalytic action of 4 is proposed.
将 4-氯-1-苯基-1H-吡唑并[3, 4-d]嘧啶(9)、芳香醛(5)、氢化钠和催化剂量的 1、在四氢呋喃中回流 1,3-二甲基苯并咪唑鎓碘化物(4),发生亲核酰化反应,生成芳基 1-苯基-1H-吡唑并[3,4-d]嘧啶-4-基酮(11)。与 4-氯-1-甲基-1H-吡唑并[3, 4-d]嘧啶(10)的类似反应以中等产率得到了相应的芳基 1-甲基-1H-吡唑并[3, 4-d]嘧啶-4-基酮(12)。在上述反应中使用二甲基甲酰胺或二甲基亚砜可缩短必要的反应时间,降低反应温度。在 4 的催化作用下,提出了形成酮 11 和酮 12 的合理反应途径。