The mass spectrometric behavior of 1,2,4-oxadiazolyl-N-methylpyridinium salts has been investigated. These substances are of current interest as perspective ionic liquids, compounds used as green solvents for synthesis, and for their catalytic properties. The studies have been developed through electrospray ionization tandem mass spectrometry (ESI-MS/MS) experiments. The obtained results demonstrate a ready distinction between the two isomeric classes, 3-N-methylpyridinium- and 5-N-methylpyridinium-1,2,4-oxadiazoles, is possible through ESI-MS/MS experiments. A deeper investigation on the principal fragmentation pathways of characteristic ions has been also developed.
FullerJ.CarlinR.T.OsteryoungR.A., “The Room Temperature Ionic Liquid 1-Ethyl-3-methylimidazolium Tetrafluoroborate: Electrochemical Couples and Physical Properties”, J. Electrochem. Soc.144, 3881 (1997). doi: 10.1149/1.1838106
4.
WilkesJ.S.LeviskyJ.A.WilsonR.A.HusseyC.L., “Dialkylimidazolium chloroaluminate melts: A new class of room-temperature ionic liquids for electrochemistry, spectroscopy and synthesis”, Inorg. Chem.21, 1263 (1982). doi: 10.1021/ic00133a078
5.
WilkesJ.S.ZaworotkoM.J., “Air and water stable 1-ethyl-3-methylimidazolium based ionic liquids”, J. Chem. Soc., Chem. Commun. (13), 965 (1992). doi: 10.1039/C39920000965
6.
DavisJ.H.JrForresterK.J.MerriganT., “Novel organic ionic liquids (OILs) incorporating cations derived from the antifungal drug miconazole”, Tetrahedron Lett.39, 8955 (1998). doi: 10.1016/S0040-4039(98)02070-X
7.
LarsenA.S.HolbreyJ.D.ThamF.S.ReedC.A., “Designing Ionic Liquids: Imidazolium Melts with Inert Carborane Anions”, J. Am. Chem. Soc.122, 7264 (2000). doi: 10.1021/ja0007511
8.
HurleyF.H.WierT.P., “Electrodeposition of Metals from Fused Quaternary Ammonium Salts”, J. Electrochem. Soc.98, 203 (1951).
9.
RobinsonJ.OsteryoungR.A., “An electrochemical and spectroscopic study of some aromatic hydrocarbons in the room temperature molten salt system aluminum chloriden-butylpyridinium chloride”, J. Am. Chem. Soc.101, 323 (1979). doi: 10.1021/ja00496a008
10.
MirzaeiY.R.TwamleyB.ShreeveJ.M., “Syntheses of 1-Alkyl-1,2,4-triazoles and the Formation of Quaternary 1-Alkyl-4-polyfluoroalkyl-1,2,4-triazolium Salts Leading to Ionic Liquids”, J. Org. Chem.67, 9340 (2002). doi: 10.1021/jo026350g
11.
MirazeiY.R.ShreeveJ.M., “New Quaternary Polyfluoroalkyl-1,2,4-Triazolium Salts Leading to Ionic Liquids”, Synthesis1, 24 (2003). doi: 10.1055/s-2003-36254
12.
XueH.TwamleyB.ShreeveJ.M., “The First 1-Alkyl-3-perfluoroalkyl-4,5- dimethyl-1,2,4-triazolium Salts”, J. Org. Chem.69, 1397 (2004). doi: 10.1021/jo0356107
13.
BuscemiS.PaceA.VivonaN., “Fluoro heterocycles. A photochemical methodology for the synthesis of 3-amino- and 3-(N-alkylamino)-5-perfluoroalkyl-1,2,4-oxadiazoles”, Tetrahedron Lett.41, 7977 (2000). doi: 10.1016/S0040-4039(00)01375-7
14.
BuscemiS.PaceA.CalabreseR.VivonaN.MetrangoloP., “Fluorinated heterocyclic compounds. A photochemical synthesis of 3-amino-5-perfluoroaryl-1,2,4-oxadiazoles”, Tetrahedron57, 5865 (2001). doi: 10.1016/S0040-4020(01)00524-5
15.
BuscemiS.PaceA.PibiriI.VivonaN., “Fluorinated heterocyclic compounds. Synthesis of 5-amino-, 5-N-alkylamino-, and 5-N,N-dialkylamino-3-perfluoroheptyl-1,2,4-oxadiazoles”, Heterocycles57, 1891 (2002).
16.
BuscemiS.PaceA.PibiriI.VivonaN.SpinelliD., “Fluorinated heterocyclic compounds. An expedient route to 5-perfluoroalkyl-1,2,4-triazoles via an unusual hydrazinolysis of 5-perfluoroalkyl-1,2,4-oxadiazoles: First examples of an ANRORC-like reaction in 1,2,4-oxadiazole derivatives”, J. Org. Chem.68, 605 (2003). doi: 10.1021/jo0262762
17.
BuscemiS.PaceA.PibiriI.VivonaN.LanzaC. Z.SpinelliD., “Fluorinated heterocyclic compounds. The first example of an irreversible ring-degenerate rearrangement on five-membered heterocycles by attack of an external bidentate nucleophile”, Eur. J. Org. Chem.974 (2004). doi: 10.1002/ejoc.200300737
18.
BuscemiS.PaceA.PibiriI.VivonaN.CaronnaT., “Fluorinated heterocyclic compounds: An assay on photochemistry of some fluorinated 1-oxa-2-azoles: An expedient route to fluorinated heterocycles”, J. Fluorine Chem.125, 165 (2004). doi: 10.1016/j.jfluchem.2003.07.006
19.
PaceA.PibiriI.BuscemiS.VivonaN.MalpezziL., “Photochemistry of fluorinated heterocyclic compounds. An expedient route for the synthesis of fluorinated 1,3,4-oxadiazoles and 1,2,4-triazoles”, J. Org. Chem.63, 4108 (2004). doi: 10.1021/jo049814e
20.
BuscemiS.PaceA.PiccionelloA. PalumboPibiriI.VivonaN., “Fluorinated heterocyclic compounds. A photochemical approach to a synthesis of fluorinated quinazolin-4-ones”, Heterocycles59, 1619 (2004).
21.
CerauloL.Di StefanoV.FerrugiaM.FotiS.SalettiR.SpinelliD., “Studies in organic mass spectrometry; Part 26. Unimolecular decomposition of ortho- methoxy-substituted diphenylmethyl cations”, Eur Mass Spectrom.5, 89 (1999).
22.
AvelloneG.CerauloL.LamartinaL.CosimelliB.SpinelliD.ZuppiroliL., “Studies in organic mass spectrometry. Part 24. Electron ionization mass spectra of some aryl(2-nitrobenzo[b]thiophen-3-yl)amines”, Rapid Commun. Mass Spectrom.13, 1360 (1999). doi: 10.1002/(SICI)1097-0231(19990730)13:14<1360::AID-RCM642>3.0.CO;2-R
23.
CerauloL.Di StefanoV.FerrugiaM.LudànyiK.SegretoS.VèkeyK., “Studies in organic mass spectrometry. Part 27. Electron ionisation induced isomerisation of 3-aryl-4(3H)-quinazolinones”, Rapid Commun. Mass Spectrom.15, 433 (2001). doi: 10.1002/rcm.241
24.
BongiornoD.CerauloL.MeleA.PanzeriW.SelvaA.LiveriV. Turco, “Guest-to-host proton transfer in melatonin-β-cyclodextrin inclusion complex by ionspray, fast atom bombardment and tandem mass spectrometry”, J. Mass Spectrom.36, 1189 (2001). doi: 10.1002/jms.226
25.
BongiornoD.CamardaL.CerauloL.FerrugiaM., “Mass Spectrometry of Simple Indoles. Part 1: Electron ionisation, Photo-ionisation and Electron capture ionisation”, in Targets in Heterocyclic Systems, Volume 7, Ed by AttanasiO. A.SpinelliD., Royal Society of Chemistry, Cambridge, UK, p. 174 (2003).
26.
BongiornoD.CamardaL.CerauloL.FerrugiaM., “Mass Spectrometry of Simple Indoles. Part 2: Fourier Transform Mass Spectrometry, Fast Atom Bombardment, Laser Desorption and Electrospray Ionisation”, in Targets in Heterocyclic Systems, Volume 8, Ed by AttanasiO.A.SpinelliD., Royal Society of Chemistry, Cambridge, UK, p. 398 (2004).
27.
PibiriI.PaceA.PiccionelloA. PalumboPierroP.BuscemiS., “Synthesis and characterization of a series of alkyl oxadiazolylpyridinium salts as perspective ionic liquids”, Heterocycles68, 2653 (2006).
MacLeodA.M.BakerR.FreedmanS.B.PatelS.MerchantK.J.RoeM.SaundersJ., “Synthesis and muscarinic activities of 1,2,4-thiadiazoles”, J. Med. Chem.33, 2052 (1990). doi: 10.1021/jm00169a041
30.
JulianR.R.HodyssR.BeauchampJ.L., “Salt Bridge Stabilization of Charged Zwitterionic Arginine Aggregates in the Gas Phase”, J. Am. Chem. Soc.123, 3577 (2001). doi: 10.1021/ja003105a
31.
DanielJ.M.FriessS.D.RajagopalanS.WendtS.ZenobiR., “Quantitative determination of noncovalent binding interactions using soft ionization mass spectrometry”, Int. J. Mass Spectrom.216, 1 (2002). doi: 10.1016/S1387-3806(02)00585-7
SelvaA.ZerilliL.F.CavalleriB.GalloG.G., “Mass spectrometry of heterocyclic compounds—II: Electron-impact induced fragmentation of 3,5-diphenyl-1,2,4-oxadiazole”, Org. Mass. Spectrom.6, 1347 (1972). doi: 10.1002/oms.1210061209
34.
SelvaA.TraldiP.ZerilliL.F.GalloG.G., “Mass spectrometry of heterocyclic compounds. XIII. Substituent effects on the mechanism of retro-1,3-dipolar cycloaddition of 3,5- diaryl-1,2,4-oxadiazoles under electron impact,”Ann. Chim.67, 371 (1977) and references therein cited.
35.
SrivastavaR.M., “Mass spectrometric analysis of 1,2,4-oxadiazoles and 4,5-dihydro-1,2,4-oxadiazoles”, Mass Spectrom. Rev.24(3), 328 (2005) and references therein cited. doi: 10.1002/mas.20017
36.
LeanersR.MousseboisC.EloyF., “Synthèse du dérivé diméthylé et de quelques dérivés monosubstitués de l'oxadiazole-1,2,4”, Helv. Chim. Acta45, 441 (1962). doi: 10.1002/hlca.19620450203
