Ionic-Liquid-Supported Synthesis of Amines and Derivatives

Abstract

Amine precursors such as glycines protected at nitrogen with a Boc or formyl group were grafted by esterification on the hydroxylated arms of 1-(2-hydroxyethyl)-3-methylimidazolium hexafluorophosphates or tetrafluoroborates. The cleavage of the Boc group was then realized at room temperature by successively treating acetonitrile solutions of the thus formed glycinates with methanol and acetyl chloride (two equivalents each). Interestingly, the resulting glycinate hydrochlorides were converted into the corresponding amines during the removal of the solvent. Ugi reaction of one of these ionic-liquid-grafted amines with phthalaldehydic acid and tert-butyl isocyanide, followed by cleavage, furnished a phthalimidine.

Key words

ionic liquids - amines - glycine derivatives - esters - Ugi reaction

References

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1

Present address: Sciences Chimiques de Rennes, UMR 6226, CNRS, Bâtiment 10A, Université de Rennes 1, Campus de Beaulieu, Avenue du Général Leclerc, 35042 Rennes Cedex, France.

15

Ugi reactions are generally performed in methanol at room temperature or 40 °C (see ref. 14).