An efficient preparation of novel 5-fluoropyrazolin-3-one derivatives from α-trifluoromethylated α-arylacetates
作者:No Kyun Park、Bum Tae Kim、Surk Sik Moon、Sung Lan Jeon、In Howa Jeong
DOI:10.1016/j.tet.2004.05.112
日期:2004.8
reactions of α-trifluoromethylated α-arylacetates 1 with 3 equiv of hydrazine, methylhydrazine or benzylhydrazine in 1,4-dioxane at reflux for 24 h afforded the corresponding 5-fluoropyrazolin-3-one derivatives 3a–m in high yields. Similarly, treatment of 1 with 3 equiv of PhNLiNH2 in THF at −78 °C, followed by warming to room temperature, resulted in the formation of 3n–s in high yields.
α-三氟甲基化的α-芳基乙酸酯1与3当量的肼,甲基肼或苄基肼在1,4-二恶烷中的反应在回流下反应24小时,从而以高收率提供了相应的5-氟吡唑啉-3-酮衍生物3a – m。同样,在−78°C下用3当量的PhNLiNH 2在THF中的溶液处理1,然后升温至室温,以高收率形成3n - s。