Synthesis of Δ<sup>2</sup>-1,3-Oxazolines and Δ<sup>2</sup>-1,3-Oxazines Using Potassium Fluoride on Alumina
作者:Michael A. Mitchell、Brian C. Benicewicz
DOI:10.1055/s-1994-25542
日期:——
Potassium fluoride (40%) on alumina was used as a basic reagent for the ring closure of N-(β- or γ-haloalkyl)amides to give Î2-1,3-oxazolines and Î2-1,3-oxazines, respectively. Various 2-alkyl and 2-aryl derivatives were synthesized in moderate to high yield under relatively mild conditions (KF/Al2O3, solvent, room temperature). The procedure also facilitated simple workup and purification of the products. New compounds synthesized by this method are: 5-bromomethyl-2-phenyl-Î2-1,3-oxazoline, 4,4-dimethyl-2-vinyl-Î2-1,3-oxazoline, and 5-methylene-2-phenyl-Î2-1,3-oxazine. The last compound represents the first authentic example of a 5-functionally substituted oxazine without substitution in the 4- or the 6- position.
氧化铝上的氟化钾 (40%) 用作 N-(β- 或 γ-卤代烷基) 酰胺闭环的碱性试剂,得到 α2-1,3- 恶唑啉和 β2-1,3-分别为恶嗪。在相对温和的条件(KF/Al2O3,溶剂,室温)下,以中等至高产率合成了各种2-烷基和2-芳基衍生物。该程序还促进了产品的简单后处理和纯化。该方法合成的新化合物有:5-溴甲基-2-苯基-α2-1,3-恶唑啉、4,4-二甲基-2-乙烯基-β2-1,3-恶唑啉和5-亚甲基-2-苯基-α2-1,3-恶嗪。 最后一个化合物代表了第一个在 4-位或 6-位没有取代的 5-官能取代恶嗪的真实例子。