Synthesis of 2-substituted pyridines via a regiospecific alkylation, alkynylation, and arylation of pyridine N-oxides.
[structure: see text]. Sequential addition of Grignard reagents to pyridine N-oxides in THF at room temperature followed by treatment with acetic anhydride at 120 degrees C afforded 2-substituted pyridines in good to high yields. Furthermore, by exchanging acetic anhydride for DMF in the second step, 2-substituted pyridine N-oxides were obtained, as intermediates suitable for addition of a second Grignard reagent for the synthesis of 2,6-disubstituted pyridines.
Andersson
Hans
H
Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden.
Almqvist
Fredrik
F
Olsson
Roger
R
D000478:Alkylation; D000480:Alkynes / Q000737:chemistry*; D015394:Molecular Structure; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry*
D000480:Alkynes; D011084:Polycyclic Aromatic Hydrocarbons; D011725:Pyridines; C013229:pyridine N-oxide