Regioselectivity of Electrophilic Attack on 4-Methyl-1-Thioxo-1,2,4,5-Tetrahydro1,2,4Triazolo4,3-AQuinazolin-5-One Part 2: Reactions on Nitrogen Atom

摘要

The regioselectivity on a cyclic thioamide group towards different electrophiles was studied on the model compound 4-methyl-1-thioxo-1,2,4,5-tetrahydro1,2,4triazolo 4,3-aquinazolin-5-one 1. The examined compound 1 reacts with alkyl halides, amines in the presence of formaldehyde, acyl halides and compounds having activated double bonds to afford the N-substituted derivatives 2, 3 and 6. The regioselective reactions on nitrogen atom are due to strong Coulombic attraction. The reaction of 1 with amines in the presence of hydrogen peroxide afforded the aminolysis product 4. Compounds 1-6 were identified by FTIR, 1H NMR, 13C NMR, and mass spectroscopy.