Eine verbesserte Methode zur Herstellung von 1,3,3-Trialkyl-2-alkylidenindolinen

An Improved Method for the Synthesis of 1,3,3-Trialkyl-2-alkylideneindolines Alkylation of 1,3,3-trialkyl-2-methyleneindolines 1a,b with iodomethane and iodomethane, respectively, under optimized reaction conditions in tetrahydrofuran provides 1,3,3-trialkyl-2-alkylideneindolines 3a–c as mixtures of (E)/(Z) isomers (yield ca. 40–50%), which can be converted into the corresponding tetrafluoroborates 5a,b. The 1H- and 13C-NMR spectra of 3a–c and 5a,b are reported.