Ethyl 3-(thiophen-2-yl)piperazine-1-carboxylate → 1-Methyl-3-(thiophen-2-yl)piperazine
Reaktionsgleichung
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1[CH:6]1[NH:11][CH2:10][CH2:9][N:8]([C:12](OCC)=O)[CH2:7]1.[H-].[Al+3].[Li+].[H-].[H-].[H-]>C(OCC)C>[CH3:12][N:8]1[CH2:9][CH2:10][NH:11][CH:6]([C:2]2[S:1][CH:5]=[CH:4][CH:3]=2)[CH2:7]1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A solution of ethyl 3-(2-thienyl)piperazine-carboxylate (27.2 g, 0.11 mol; Preparation 2) in diethyl ether (300 ml) is added to a stirred suspension of lithium aluminum hydride (10.8 g, 0.28 mol) in diethyl ether (1300 ml). The mixture is refluxed for 12 h, cooled to room temperature and worked up as described in "Reagents for Organic Synthesis" , Fieser, L. F. and Fieser, M., John Wiley and Sons, Inc., New York, N.Y. 1967, p. 583. The ether solution is dried (potassium carbonate) and evaporated to give 1-methyl-3-(2-thienyl)piperazine as a light yellow oil, which is characterized as the maleate salt (m.p. 123°-124.5° C.), which is prepared in the manner described in Preparation 2.