The condensation of primary amine with N,N-dimethylacetamide dimethyl acetal yields a mixture of acetamidine and imidate ester. The product distribution in this reaction depends on the temperature, solvent, and structure of the primary amine. It is possible to suppress the formation of imidate ester by performing the reaction in the presence of excess dimethyl amine, yielding acetamidine as the exclusive product. For acetamidines that cannot be purified either by crystallization or distillation, this new method is necessary for the generation of pure acetamidines in good yields.
Contrasting Reactivity of CS<sub>2</sub>with Cyclic vs. Acyclic Amidines
作者:M. Trisha C. Ang、Lam Phan、Aliyah K. Alshamrani、Jitendra R. Harjani、Ruiyao Wang、Gabriele Schatte、Nicholas J. Mosey、Philip G. Jessop
DOI:10.1002/ejoc.201500973
日期:2015.11
to give an isothiocyanate and a thioacetamide. Because the pathway to that cleavage involves a rotation that is difficult for cyclic amidines, the reaction of CS2 with cyclic amidines produces an entirely different product: a cyclic carbamic carboxylic trithioanhydride structure. The path to that product involves sp3 C-H activation leading to the formation of a new C–C bond at a carbon α to the central
作者:Jitendra R. Harjani、Chen Liang、Philip G. Jessop
DOI:10.1021/jo102358d
日期:2011.3.18
The condensation of primary amine with N,N-dimethylacetamide dimethyl acetal yields a mixture of acetamidine and imidate ester. The product distribution in this reaction depends on the temperature, solvent, and structure of the primary amine. It is possible to suppress the formation of imidate ester by performing the reaction in the presence of excess dimethyl amine, yielding acetamidine as the exclusive product. For acetamidines that cannot be purified either by crystallization or distillation, this new method is necessary for the generation of pure acetamidines in good yields.
Cyclocondensation of amidines with dimethyl acetylenedicarboxylate: A convenient entry into tetramic acids
作者:Ihsan Erden、Galip Ozer、Christophe Hoarau、Weiguo Cao
DOI:10.1002/jhet.5570430220
日期:2006.3
Amidines undergo cyclocondensations with dimethylacetylenedicarboxylate (DMAD) to give highly functionalized 5-dialkylamino-4-pyrrolin-3-ones. The products are crystalline, highly colored compounds that are uniquely functionalized and represent advanced intermediates in the construction of several other heterocyles, in particular the biologically active tetramicacids. The synthetic transformations