21731-13-5Relevant articles and documents
Aza-annulation of enaminones with crotonyl chloride - formal reversal of regioselectivity
Murphy, James P.,Hadden, Mark,Stevenson, Paul J.
, p. 11827 - 11834 (1997)
The regiochemistry of aza-annulation of enaminones with a,β-unsaturated acid chlorides bearing hydrogen atoms on the γ-carbon is reversed when triethylamine is used as mediator. When the reaction was carried out at lower temperatures a 3-acyl β,γ-unsaturated compound could be isolated which cyclised to the desired product under thermal or basic conditions. The nature of this intermediate strongly suggests that a vinyl ketene is the active acylating agent.
Research on heterocyclic compounds. XLIII. Synthetic studies on 1,4-dihydropyridine derivatives
Rimoli, Maria Grazia,Avallone, Lucia,Zanarone, Serena,Abignente, Enrico,Mangoni, Alfonso
, p. 1117 - 1122 (2007/10/03)
In order to obtain N-benzyl-3,5-dicarbethoxy-2,6-dimethyl-4-phenyl-1,4-dihydropyridine 1 as a lead compound of pharmacological interest, the classical Hantzsch synthetic method and the modified Collie procedure were used. However, only a very low yield of
On the Mechanism of Pyrrole Formation in the Knorr Pyrrole Synthesis and by Porphobilinogen Synthase
Fabiano, Emmanuel,Golding, Bernard T.
, p. 3371 - 3376 (2007/10/02)
Attempts to synthesise a derivative of N-vinylaminoethanal either by oxidation of the corresponding alcohol or by hydrolysis of the corresponding dithioacetal were unsuccessful, but such derivatives were characterised by 1H and 13C NMR spectroscopy of reactions between ethyl 2-aminoacetoacetate and an excess of ethyl acetoacetate, leading to diethyl 2,4-dimethylpyrrole-3,5-dicarboxylate.
