作者:Alejandro Cruz、Rosalinda Contreras、Itzia I. Padilla-Martínez、Minerva Juárez-Juárez
DOI:10.1016/j.tetasy.2006.05.009
日期:2006.6
Herein, a direct and easy method for preparing 2-oxo-, 2-thione- or 2-imine-1,3-heterazolidines derived from ephedrines and norephedrines are reported. The method is based on solvent free heating of ephedrines with oxocyanate or thiocyanate salts (180-200 degrees C). In the reactions with potassium oxocyanate in refluxing ethanol, it was possible to isolate ureidic derivatives. The structure and stereochernistry of the compounds were determined by H-1, C-13 NMR, IR spectroscopies and mass spectrometry. Ureidic derivatives, cis- 1,5-dimethyl-4-phenyl-imidazolidine-2-thione and trans-4-methyl-5-phenyl-thiazolidine-2-one are new compounds. Ephedrineurea, cis- 1,5-dimethyl-4-phenyl-imidazolidine-2-thione and trans-4-methyl-5-phenyl-thiazolidine-2-one were also studied by X-ray diffraction. (c) 2006 Elsevier Ltd. All rights reserved.