作者:Keith Smith、Gamal A. El-Hiti、Safaa A. Mahgoub
DOI:10.1055/s-2003-41064
日期:——
3-Methyl-1H-quinoxalin-2-one has been doubly lithiated with n-butylithium at -78 °C in THF. The dilithio reagent thus obtained reacts with various electrophiles (iodomethane, iodoethane, D2O, benzaldehyde, benzophenone, cyclohexanone) to give modified 3-substituted 1H-quinoxalin-2-ones in good yields. In the reaction of the dilithio reagent with phenyl isothiocyanate the product was a tautomer of the simple substitution product. Reaction of the dilithio reagent with iodine gives an oxidatively dimerised product instead of the 3-iodomethyl derivative. Lithiations of 3-ethyl- and 3-propyl-1H-quinoxalin-2-ones, followed by reactions with representative electrophiles (benzaldehyde, benzophenone, cyclohexanone), behaved in a similar manner to give the corresponding modified 3-substituted derivatives in good yields.
3-甲基-1H-喹喔啉-2-酮在 -78 °C 的 THF 中被正丁基锂双锂化。由此获得的二锂试剂与各种亲电子试剂(碘甲烷、碘乙烷、D 2 O、苯甲醛、二苯甲酮、环己酮)反应,以良好的收率得到修饰的3-取代的1H-喹喔啉-2-酮。在二锂试剂与异硫氰酸苯酯的反应中,产物是简单取代产物的互变异构体。二锂试剂与碘反应产生氧化二聚产物而不是3-碘甲基衍生物。 3-乙基-和3-丙基-1H-喹喔啉-2-酮的锂化,然后与代表性亲电子试剂(苯甲醛、二苯甲酮、环己酮)反应,以类似的方式产生相应的改性3-取代衍生物,收率良好。