One-Pot Acid-Promoted Synthesis of 6-Aminopyrazolopyrimidines from 1<i>H</i>-Pyrazol-5-yl-<i>N</i>,<i>N</i>-dimethylformamidines or 5-Amino-1<i>H</i>-pyrazole-4-carbaldehydes with Cyanamide
作者:Ching-Chun Tseng、Shuo-En Tsai、Sin-Min Li、Fung Fuh Wong
DOI:10.1021/acs.joc.9b02653
日期:2019.12.20
acid-promoted synthesis of 6-aminopyrazolo[3,4-d]pyrimidine has been developed by treatment of 1H-pyrazol-5-yl-N,N-dimethylformamidines or 5-amino-1H-pyrazole-4-carbaldehydes with cyanamide (NH2C≡N) in an acid-mediated solution. This syntheticroute involves four steps of deprotection, imination, the key acid-promoted heterocyclization, and aromatization. On the basis of optimized studies, methanesulfonylchloride
Evaluation of Electrophilic Heteroaromatic Substitution: Synthesis of Heteroaromatic-Fused Pyrimidine Derivatives via Sequential Three-Component Heterocyclization
作者:Fung Fuh Wong、Yu-Ying Huang、Chun-Hsi Chang
DOI:10.1021/jo301463m
日期:2012.10.5
A new sequentialthree-componentheterocyclization was developed by reacting aromatic and heterocyclic substrates, including aminobenzenes, 1-aminonaphthalene, 2-aminopyrazines, 5-aminopyrazoles, 3-aminopyridine, 5-aminopyrimidine, 5-aminoquinoline, and 8-aminoquinoline, with formamide in the presence of PBr3. The reaction gave the corresponding pyrazolo[3,4-d]pyrimidines in good yields (59–96%), except
通过使芳香族和杂环底物(包括氨基苯,1-氨基萘,2-氨基吡嗪,5-氨基吡唑,3-氨基吡啶,5-氨基嘧啶,5-氨基喹啉和8-氨基喹啉)与甲酰胺反应,开发了一种新的顺序三组分杂环化方法在PBr 3存在下。除氨基苯和3-氨基吡啶外,该反应以较高的收率(59-96%)得到了相应的吡唑并[3,4- d ]嘧啶。提出了包括三步酰胺化,亲电取代亚胺化和氧化环化的合理反应机理,以解决杂环化问题。发现反应的反应性与芳族或杂环底物的亲电子性成比例。
Selective synthesis of pyrazolo[3,4-d]pyrimidine, N-(1H-pyrazol-5-yl)formamide, or N-(1H-pyrazol-5-yl)formamidine derivatives from N-1-substituted-5-aminopyrazoles with new Vilsmeier-type reagents
作者:Chun-Hsi Chang、Henry J. Tsai、Yu-Ying Huang、Hui-Yi Lin、Li-Ya Wang、Tian-Shung Wu、Fung Fuh Wong
DOI:10.1016/j.tet.2012.11.002
日期:2013.1
N-1-(2-pyridinyl)-5-aminopyrazoles, and N-1-(2-quinolinyl)-5-aminopyrazoles with these agents gave the corresponding pyrazolo[3,4-d]pyrimidine, N-(1H-pyrazol-5-yl)formamide, or N-(1H-pyrazol-5-yl)formamidine. The reaction was different from the traditional Vilsmeier-type reaction and the plausible reactive pathways were proposed for the unexpected result.
从甲酰胺或N-甲基甲酰胺与POCl 3合成了多种新型的Vilsmeier试剂卤代甲基亚铵盐。的治疗Ñ -1-取代的氨基吡唑包括Ñ -1-苯基-5-氨基吡唑,Ñ -1-(2-吡啶基)-5-氨基吡唑,和Ñ -1-(2-喹啉基)-5-氨基吡唑与这些剂得到相应的吡唑并[3,4- d ]嘧啶,N-(1 H-吡唑-5-基)甲酰胺或N-(1 H-吡唑-5-基)甲idine。该反应不同于传统的Vilsmeier型反应,并提出了可能的反应途径以取得意想不到的结果。
Efficient acid catalytic synthesis of pyrazolopyrimidines from 1H-pyrazol-5-yl-N,N-dimethylformamidines with cyanamide
The efficient acid catalytic synthesis of pyrazolo [3,4-d]pyrimidine was developed by treating 1H-pyrazol-5-yl-N,N-dimethylformamidine with various aminating agents including N,O-bis(trimethylsilyl)hydroxylamine (NHSiMe3(OSiMe3)), cyanamide (NH2CN), hydroxylamine (NH2OH), methoxyamine (NH2OMe), hydrazine (NH2NH2), and urea (NH2C(O)NH2) in acidic solution at reflux. Based on the experimental result