The reaction of an aromatic heterocycle with a proton is called a protonation. One of articles about this theory is 《Conjugation phenomena in α- and β-substituted pyrroles studied by infrared and ultraviolet spectrophotometry》. Authors are Scrocco, Marisa; Caglioti, Luciano; Caglioti, V..The article about the compound:3-Methyl-1H-pyrrolecas:616-43-3,SMILESS:CC1=CNC=C1).Synthetic Route of C5H7N. Through the article, more information about this compound (cas:616-43-3) is conveyed.
cf. C.A. 51, 17455e. Effects of ring substituents on the NH stretching frequency v(NH) of pyrroles (I) are further investigated. 2-Me, 3-Me, 2,4-Me2, and 2,5-Me2 substitutions cause only a very slight increase in v(NH) of I, an effect opposite to hyperconjugation. The v(CO) of the 3-CO2Me compound previously given as 1700 cm.-1 was resolved into 2 peaks, 1712 (strong) and 1698; similarly the 2-CO2Me compound had maximum at 1715 and 1697 (strong), the lower ν presumably vibrations of internal chelates. The following data were similarly interpreted: (I substituents, strong v(NH), weak v(NH), strong v(CO), weak v(CO), ultraviolet maximum (log ε) and ultraviolet maximum (log ε) given): 3-CO2Me, 3490, 3320, 1712, 1698 cm.-1, 240 mμ (3.82), and – (-); 2-CO2Me, 3326, 3472, 1697, 1715 cm.-1, 261 (4.22) and 234.5 mμ (3.82); 2-CHO, 3284, 3468, 1650, 1666 cm.-1, 279 (4.27), and 246 mμ (3.73); 2-Ac, 3294, 3466, 1640, 1662 cm.-1, 276.5 (4.21) and 247 mμ (3.61); 2-COCH2Cl, -, -, 1639, 1663 cm.-1, 288.5 (4.3) and 246 mμ (3.6); 2-CO2Me, 4-NO2, -, -, -, -, 229 (4.26) and 285 mμ (3.75); 2-Ac, 5-CN, -, -, -, -, 248 (3.85) and 265 mμ (3.80).
After consulting a lot of data, we found that this compound(616-43-3)Synthetic Route of C5H7N can be used in many types of reactions. And in most cases, this compound has more advantages.
Reference:
Synthesis and Crystal Structure of a Chiral C3-Symmetric Oxygen Tripodal Ligand and Its Applications to Asymmetric Catalysis,
Chiral lanthanide(III) complexes of sulphur–nitrogen–oxygen ligand derived from aminothiourea and sodium D-camphor-β-sulfonate