Synthesis and study of biological activity of azometins based on ethyl derivatives 4-acetyl-3,5-dimethyl-1H-pyrol-2-carboxylate

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

“…It is known that the Ugi-4CR proceeds through the formation of an azomethine (Schiff base) in the first stage [ 39 – 40 ]. Therefore, considering the results of our previous work [ 39 ] on the nature and properties of azomethines based on β-chlorovinylaldehyde 1 ( Figure 1 ), we decided to study the possibility of using the three-component Ugi reaction (Ugi-3CR) with preliminary synthesis of azomethines 9a – c ( Table 1 ). In this case, the Ugi bisamides 5 , 6 , 8 were formed, however, it was found that the application of the Ugi-3CR approach had no significant effect on the yields of the target products.…”

“…The creation of hybrid molecules by using primary and post-modified Ugi products in combination with other isocyanide MCRs is effective and one promising direction to increase the diversity of new peptidomimetics is the use of, for example, α,β-unsaturated aldehydes including those containing a halogen atom in the β-position, in the Ugi-4CR reaction [ 1 , 39 ].…”

“…As our previous studies have shown, azomethines based on aromatic amines and substituted pyrrolecarbaldehyde [ 40 ] or pyrrolyl-β-chlorovinylaldehyde [ 39 ], contain several frequently encountered motifs in drugs and drug candidates – a pyrrole heterocycle and an azomethine C=N fragment ( Figure 1 ) – and exhibit some biological activity. Thus, Ugi bisamides based on the same aldehydes and amines may also demonstrate biological activity.…”