Straightforward access to ethyl 3-aminofuropyridine-2-carboxylates from 1-chloro-2-cyano- or 1-hydroxy-2-cyano-substituted pyridines
The conditions of the synthesis of the four regioisomers of ethyl 3-aminofuropyridine-2-carboxylate are described and discussed in detail. The starting materials are either 1-chloro-2-cyanopyridines or 1-cyano-2- hydroxypyridines. Georg Thieme Verlag Stuttgart.
Synthesis of ortho-substituted cyanopyridines through lithio intermediate trapping
Ortholithiation of 4-cyanopyridine using 2,2,6,6-tetramethylpiperidide (LiTMP) and trapping the lithio intermediate with electrophiles represents an efficient and straightforward access to ortho-substituted-4-cyanopyridines. The cyano group can be used as an ortho-directing group and allows the preparation of 3-halogeno-4-cyanopyridines. Reactivity of 2- and 3-cyanopyridines is also investigated and seems to give similar results.