Ultrasonic-Promoted One-Pot Synthesis of 4H-chromenes, pyrano[2,3- d]pyrimidines, and 4H-pyrano[2,3-c]pyrazoles
作者:Davood Azarifar、Razieh Nejat-Yami、Fatemeh Sameri、Zahra Akrami
DOI:10.2174/157017812801322435
日期:2012.6.1
A facile and versatile procedure has been explored for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4Hchromenes,
pyrano[2,3-d]pyrimidines and 1,4-dihydropyrano[2,3-c]pyrazole-5-yl cyanides. This protocol employs the
one-pot three-component condensation of aromatic aldehydes and malononitrile with 5,5-dimethyl-cyclohexane-1,3-
dione, 1,3-dimethyl barbituric acid or 3-methyl-1-phenyl-2-pyrazolin-5-ones respectively in ethanol under the catalytic effect
of triethylamine and ultrasonic-irradiation conditions. Simple manipulation, high reaction rates, improved yields, use
of inexpensive and non-toxic catalyst, and also use of ethanol as a relatively environmentally benign solvent are the main
advantages of this protocol.
研究人员探索了一种简便、通用的合成 2-氨基-5-氧代-5,6,7,8-四氢-4-苯并吡喃、吡喃并[2,3-d]嘧啶和 1,4-二氢吡喃并[2,3-c]吡唑-5-基氰化物的方法。在三乙胺催化和超声波照射条件下,芳香醛和丙二腈分别与 5,5-二甲基-1,3-环己烷二酮、1,3-二甲基巴比妥酸或 3-甲基-1-苯基-2-吡唑啉-5-酮在乙醇中进行一锅三组分缩合反应。操作简单、反应速度快、产率高、使用廉价无毒催化剂,以及使用乙醇作为相对环保的溶剂,是该方法的主要优点。