Synthesis of 2‐substituted 4‐oxo‐5‐nitropyrimidines from methyl 3‐ethoxy‐2‐nitroacrylate and other reactions

Abstract

Methyl 3‐ethoxy‐2‐nitroacrylate (MENA) (1) has been the subject of study for the development of new syntheses leading to nitro‐substituted heterocycles.

Trisubstituted push-pull nitro alkenes

“…Z-isomers differ due to the conformation of the carbonyl group toward double bond (Figure 2). The authors confirmed the presence of all three isomers and established E/Z ratios based on the correlation of 1 H, 13 C NMR, and IR spectra. From these results they concluded that (i) substrates crystallize as one of those isomers, however, they may isomerize even in the solid state.…”

“…The first group contains mostly pyrimidine or pyrimidone derivatives (Scheme 9) that are formed by reactions with ureas and amidines. [13][14][15]18,31,34,59,60 There are also examples of other six-membered heterocycles (pyridine 35 and thiadiazine 61 ) prepared in a similar manner. The second group contains structurally more different products (Scheme 10) that are formed by reaction with usually amino heterocycles as 1,3-binucleophiles.…”

“…Trisubstituted push-pull nitro alkenes are one of the most important compounds of such omitted nitro alkenes group (Figure 1). Disubstituted push-pull nitro alkenes (without another electron acceptor A) undergo formations of heterocycles worse than trisubstituted nitroalkenes as another electron acceptor A can readily react in nucleophilic additions with 1,2-12 or 1,3-binucleophiles 13,14 and nitro group cannot offer such a reaction. The preparation of tetrasubstituted nitroalkenes is less convenient than trisubstituted nitroalkenes in terms of yields, a number of methods, reaction times, temperatures, and toxicity of required reagents.…”