Synthesis of Enantiopure Bis-Heterocycles Derived from (<i>S</i>)-Prolinehydrazides
作者:Adam M. Pieczonka、Grzegorz Mlostoń
DOI:10.1080/10426507.2012.738737
日期:2013.4.1
A convenient synthesis of new enantiomerically pure bis-heterocycles containing a (S)-proline moiety starting from (S)-N-benzylprolinehydrazide (1) is described. The reactions of 1b with isothiocyanates in refluxing MeOH led to the thiosemicarbazide 3 with a N-benzylprolinoyl residue. Thiosemicarbazide 3 underwent cyclization reactions under basic (NaOH) and acidic (H2SO4) conditions to yield (S)-prolinyl-substituted 1,2,4-triazole-3-thione 4 and 1,3,4-thiadiazole-2-amine 5, respectively.