An unexpected formation of pyrazolopyrimidines during the attempted to obtain 5-substituted tetrazoles from carbonitriles
作者:Jéssica Venância Faria、Maurício Silva dos Santos、Percilene Fazolin Vegi、Julio Cesar Borges、Alice M.R. Bernardino
DOI:10.1016/j.tetlet.2013.08.033
日期:2013.10
1H-pyrazolo[3,4-d]pyrimidine derivatives 6a–c from 5-amino-1-aryl-3-methyl-1H-pyrazole-4-carbonitriles 4a–c, instead of 5-(5-amino-1-aryl-3-methyl-1H-pyrazole-4-yl)-1H-tetrazoles 5a–c as desired. In an attempt to obtain these tetrazole derivatives containing the methyl group at C3-position in the pyrazole ring, the amino group in 5-amino-1-(4-methoxyphenyl)-3-methyl-1H-pyrazole-4-carbonitrile 4c was protected
在该信中,我们描述的新的5-(5-氨基-1-芳基- 1合成H-吡唑-4-基)-1- ħ -tetrazoles 2A - Ç从5-氨基-1-芳基- 1 H ^ -吡唑-4-腈1a – c以及意外的1 H-吡唑并[3,4- d ]嘧啶衍生物6a – c来自5-氨基-1-芳基-3-甲基-1 H-吡唑-4-腈4a – c,而不是5-(5-氨基-1-芳基-3-甲基-1 H-吡唑-4-基)-1 H-四唑5a – c如预期的。为了获得这些在吡唑环的C 3位上含有甲基的四唑衍生物,尝试了5-氨基-1-(4-甲氧基苯基)-3-甲基-1 H-吡唑-4-腈4c中的氨基。通过用氢化钠和二-反应保护叔丁基-二碳酸酯(BOC)。使用类似方法从受保护的化合物7c合成四唑衍生物5c,得到2a – c和6a – c。