... 3,4]. The regioselectivity of the N/O- alkylation for a nitrogen heterocyclic ambident anion ... the nature of the base, the structure of alkyl halide, substituents on the heterocycles, reaction temperature ... nmr (deuteriochloro- form): δ 8.06 (s, 1H), 8.67 (m, 2H), 8.85 (d, 1H, J = 9.3); 13C ...