New pyrazolium-carboxylates as structural analogues of the pseudo-cross-conjugated betainic alkaloid Nigellicine

A Schmidt, T Habeck, MK Kindermann…

文献索引：Schmidt, Andreas; Habeck, Tobias; Kindermann, Markus Karl; Nieger, Martin Journal of Organic Chemistry, 2003 , vol. 68, # 15 p. 5977 - 5982

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被引用次数: 55

摘要

Pyrazolium-3-carboxylates were examined as relatives of the betainic alkaloid Nigellicine and as new examples of the sparsely populated class 16 of heterocyclic pseudo-cross- conjugated mesomeric betaines (PCCMB). The title compounds were prepared in a 4-step procedure starting from β-diketo compounds 8 which were cyclized with substituted hydrazines. The resulting isomeric pyrazole esters 9 and 10 were separated and ...