24541-74-0Relevant articles and documents
Supersonic jet studies of alkyl-substituted pyrazines and pyridines. Minimum energy conformations and torsional motion
Seeman, Jeffey I.,Paine III, John B.,Secor, Henry V.,Im, Hoong-Sun,Bernstein
, p. 5269 - 5280 (2007/10/02)
Conformational reference for methyl-, ethyl-, propyl-, and isoproply-substituted pyrazines and pyridines are determined by mass resolved excitation spectroscopy (MRES) and MOPAC 5/PM3 semiempirical calculations. The results of these studies suggest that the conformational behavior of alkyl-substituted pyrazines and pyridines is different from that of alkyl-subtituted benzenes. Based on the experimental and semiempirical theoretical results reported herein and published ab initio calculations, this difference can be attributed to a stabilizing interaction between an α-hydrogen atom of alkyl subsituted and the adjacent lone pair nonbonding electrons on the ring nitrogen atom.
The Wolff-Kishner Reduction of 2-Acetonyl Pyrazines and Pyridines. A Novel Rearrangement
Paine III, John B.
, p. 1463 - 1465 (2007/10/02)
Wolff-Kishner reduction of 1-(6-methylpyrazin-2-yl)-2-propanone leads to the formation of 2-isopropyl-6-methylpyrazine (2a), in addition to the expected 6-methyl-2-n-propylpyrazine.The by-product 2a is suggested to arise via a spirocyclopropylidene aza-anion, which serves as a conduit between the initial less-stable secondary 1-(2-pyrazinyl)-2-propyl carbanion and the more stable primary 2-(2-pyrazinyl)-1-propyl carbanion.Similar results were observed for the 1-(3-methylpyrazin-2-yl) and 1-(6-methylpyridin-2-yl)-2-propanones.The extent of by-product formation diminished in the pyridine ring system.Electrophilic activation of the ring appears essential since the benzene ring analog phenylacetone gave no detectable cumene under identical reaction conditions.
