Highly efficient thermal cyclization reactions of alkylidene esters in continuous flow to give aromatic/heteroaromatic derivatives
作者:László Lengyel、Tibor Zs. Nagy、Gellért Sipos、Richard Jones、György Dormán、László Ürge、Ferenc Darvas
DOI:10.1016/j.tetlet.2011.11.125
日期:2012.2
Intramolecular thermal cyclization and benzannulation reactions of the Gould–Jacobs and Conrad–Limpach types were performed in a designed continuous flow reactor system at temperatures in the range of 300–360 °C and under high pressure conditions (100–160 bar) with very short residence times (0.45–4.5 min) in tetrahydrofuran as a low-boiling point solvent. Substituted heteroaromatic compounds including
Gould–Jacobs和Conrad–Limpach类型的分子内热环化和苯环化反应在设计的连续流反应器系统中在300–360°C的温度范围内和高压条件下(100–160 bar),非常短的时间内进行在四氢呋喃中作为低沸点溶剂的停留时间(0.45-4.5分钟)。以中等至高收率合成了取代的杂芳族化合物,包括吡啶并嘧啶酮和羟基喹啉。应用反应条件还可以合成萘酚和联苯衍生物。该过程涉及容易的后处理,并且非分批制备的合成方法适合于自动化。