作者:Adam M. Pieczonka、Grzegorz Mlostoń、Anthony Linden、Heinz Heimgartner
DOI:10.1002/hlca.201200400
日期:2012.9
Enantiomerically pure bis‐heterocycles containing a (S)‐proline moiety have been prepared starting from (S)‐N‐benzylprolinehydrazide (2b). The reactions with isothiocyanates or butyl isocyanate in refluxing MeOH led to the corresponding thiosemicarbazide 5 and semicarbazide 9 with a N‐benzylprolinoyl residue. The structure of the tert‐butyl derivative 5d was established by X‐ray crystallography. Base‐catalyzed
从(S)-N-苄基脯氨酸酰肼(2b)开始制备了含有(S)-脯氨酸部分的对映体纯双杂环。与异硫氰酸酯或异氰酸丁酯在回流的MeOH中反应,生成相应的具有N-苄基脯氨酰基残基的硫代氨基脲5和氨基脲9。叔丁基衍生物5d的结构通过X射线晶体学确定。5和9的碱催化环化导致(S)-3-(吡咯烷基-2-基)-1 H -1,2,4-三唑-5(4 H)-thiones 6和相应的5-(4- ħ) -酮8,分别,而在浓硫酸2 SO 4,化合物5进行环化反应,得到(小号)-5-氨基-2-(吡咯烷-2-基) -1,3,4-噻二唑7。此外,图2b在沸腾用己烷-2,5-二酮反应,我PrOH中,得到(小号- )ñ - (2,5-二甲基吡咯-1-基)脯氨酰胺10。在双杂环化合物8的情况下,用HCOONH 4和Pd / C在MeOH中处理得到脱苄基产物12。