Pyrrole chemistry. XXIV. The Vilsmeier formylation and the cyanation of pyrrole acetals. A synthesis of pyrrole-2,3,5-tricarboxaldehyde was written by Loader, Charles E.;Barnett, Graham H.;Anderson, Hugh J.. And the article was included in Canadian Journal of Chemistry in 1982.SDS of cas: 81698-03-5 The following contents are mentioned in the article:
The preparation of the acetals of a number of pyrrole mono- and dicarboxaldehydes is described. It is shown that, provided the reactivity of the unsubstituted ring positions on the pyrrole nucleus is not too low, a carboxaldehyde or a carbonitrile group may be substituted onto the pyrrole ring using the Vilsmeier reaction or chlorosulfonyl isocyanate, resp. Vilsmeier formylation of the diacetal, 2,4-bis(5,5-dimethyl-1,3-dioxan-2-yl)pyrrole, followed by hydrolysis gave pyrrole-2,3,5-tricarboxaldehyde. This study involved multiple reactions and reactants, such as 5-Formyl-1-methyl-1H-pyrrole-2-carbonitrile (cas: 81698-03-5SDS of cas: 81698-03-5).
5-Formyl-1-methyl-1H-pyrrole-2-carbonitrile (cas: 81698-03-5) belongs to nitriles. The electronic structure of nitriles is very similar to that of an alkyne with the main difference being the presence of a set of lone pair electrons on the nitrogen. In conventional organic reductions, nitrile is reduced by treatment with lithium aluminium hydride to the amine. Reduction to the imine followed by hydrolysis to the aldehyde takes place in the Stephen aldehyde synthesis, which uses stannous chloride in acid.SDS of cas: 81698-03-5
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts