Regioselective synthesis of novel 4-aryl-2-ethylthio-7-methyl pyrazolo[1,5-a]-[1,3,5]-triazines
作者:Henry Insuasty、Martín Estrada、Edward Cortés、Jairo Quiroga、Braulio Insuasty、Rodrigo Abonía、Manuel Nogueras、Justo Cobo
DOI:10.1016/j.tetlet.2006.05.168
日期:2006.7
Pyrazolo[1,5-a]-[1,3,5]-triazines 6a–d were obtained by an efficient one-step reaction from S,S-diethyl aroyliminodithiocarbonates 4a–d and 5-amino-3-methylpyrazole 5 or by an alternative two-step reaction from 5 and aroyl isothiocyanates 8a–d to give initially the thiourea derivatives 9a–d, which after S-ethylation and cyclization afforded compounds 6a–d. The intermediate 7a isolated from reaction
吡唑并[1,5- a ]-[1,3,5]-三嗪6a - d是通过有效的一步反应从S,S-二乙基芳基亚氨基二硫代碳酸酯4a - d和5-氨基-3-甲基吡唑5或通过从替代两步反应5和芳酰基异硫氰酸酯8A - d最初得到硫脲衍生物9A - d,这后S-乙基化和环化,得到化合物6a中- d。中间体7a从4a之间的反应中分离出来和5允许我们确定方向。