Regioselective Synthesis of 2,6-Dimethyl-3,5-bis[(3-aryl-5-trifluoromethyl)-isoxazol-4-carbonyl]-pyridine Derivatives
作者:Yindi Yang、Min Zhang、Yiwen Zhu、Li Zhang、Qiqiang Xie、Liping Song、Hongmei Deng
DOI:10.1002/cjoc.201300366
日期:2013.7
Ethyl 4,4,4‐trifluoro‐3‐oxo‐butyrate reacted with 2,6‐dimethyl‐3,5‐diacetyl‐pyridine 1 in the presence of NaOC2H5 at 0°C to give 2,6‐dimethyl‐3,5‐bis(4,4,4‐trifluoro‐1,3‐oxo‐butyl)‐pyridine (2a) in good yield. Cyclization reaction of 2a and aryl imidoyl chlorides 5a–5i, obtained from chlorination of aryl oximes with N‐chlorosuccimide, afforded 2,6‐dimethyl‐3,5‐bis[(3‐aryl‐5‐trifluoromethyl)‐isoxaz
在0°C存在NaOC 2 H 5的情况下,4,4,4-三氟-3-氧代丁酸乙酯与2,6-二甲基-3,5-二乙酰基吡啶1反应,得到2,6-二甲基-二甲基吡啶3,5-二(4,4,4-三氟-1,3-氧代丁基)-吡啶(2a)收率良好。由芳基肟与N-氯代琥珀酰亚胺氯化制得的2a和芳基亚氨酰氯5a - 5i的环化反应得到2,6-二甲基-3,5-双[(3-芳基-5-三氟甲基)-异恶唑-4-羰基]-吡啶衍生物6a - 6i。