On the preparation of 1-aryl-2-heteroaryl- and 2-aryl-1-heteroarylpyrroles as useful building blocks for biologically interesting heterocycles was written by Almerico, Anna Maria;Montalbano, Alessandra;Diana, Patrizia;Barraja, Paola;Lauria, Antonino;Cirrincione, Girolamo;Dattolo, Gaetano. And the article was included in ARKIVOC (Gainesville, FL, United States) [online computer file] in 2001.Reference of 28020-37-3 This article mentions the following:
A series of 1-aryl-2-pyridinyl/pyrimidinyl-pyrroles and 2-aryl-1-pyridinyl/pyrimidinyl-pyrroles were prepared by using 4+1 ring synthesis. The yields were strongly dependant on the reactivity of the starting amines. Synthetic procedures involving a 3+2 ring formation were discussed. Few 1-heteroaryl derivatives showed weak activity when tested as COX-1 and COX-2 inhibitors. In the experiment, the researchers used many compounds, for example, 3-Amino-2,6-dimethoxypyridine (cas: 28020-37-3Reference of 28020-37-3).
3-Amino-2,6-dimethoxypyridine (cas: 28020-37-3) belongs to pyridine derivatives. The ring atoms in the pyridine molecule are sp2-hybridized. The nitrogen is involved in the π-bonding aromatic system using its unhybridized p orbital. The lone pair is in an sp2 orbital, projecting outward from the ring in the same plane as the σ bonds. One of the examples of pyridines is the well-known alkaloid lithoprimidine, which is an A3 adenosine receptor antagonist and N,N-dimethylaminopyridine (DMAP) analog, commonly used in organic synthesis.Reference of 28020-37-3