Research Article
Does the Intramolecular Hydrogen Bond Affect the Spectroscopic Properties of Bicyclic Diazole Heterocycles?
Scheme 1
Schematic representation of the structure and atom numbering of pyrrolopyrazinone derivatives (2–22) where R2 = CH3, CH2Cl, or CHCl2; R3 = H, Cl, CH3, (CH2)nCH3, (CH2)nCH2Cl, (CH2)nNH2, NH2, and (CH2)3NHC(NH)NH2.