The author of 《Zwitterionic σ-complexes: their role as intermediates in phosphorylation of aromatics by phosphorus compounds》 were Gololobov, Yu. G.; Onys’ko, P. P.. And the article was published in ACS Symposium Series in 1981. COA of Formula: C5H5N3O3 The author mentioned the following in the article:
Reaction of P(III) compounds with 1,3,5-(O2N)3C6H3 in Me2SO gave σ-complexes I [PR3 = P(OEt)3, PPh(OEt)2, P(OEt)Ph2, P(O)(OEt)2], which were stabilized without a dissociated cation in contrast to ordinary Meisenheimer σ-complexes. 5-Nitropyrimidines do not form stable σ-complexes with (RO)3P or (RO)2P(O)H without bases. II [R = alkyl; R1 = H, MeO, Ph, R2 = H; R1 = H, MeO, R2 = MeO] were prepared only in the presence of Et3N. In addition to this study using 2-Methoxy-5-nitropyrimidine, there are many other studies that have used 2-Methoxy-5-nitropyrimidine(cas: 14001-69-5COA of Formula: C5H5N3O3) was used in this study.
2-Methoxy-5-nitropyrimidine(cas: 14001-69-5) is a member of ether. Friedel Crafts reaction, for example, adds an alkyl or acyl group to aromatic ethers when they react with an alkyl or acyl halide in the presence of a Lewis acid as a catalyst.COA of Formula: C5H5N3O3
Referemce:
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia