Procedures for high-yield syntheses of 2-ethoxy- and 2-dimethylamino-4-arylpyrido [2,3-d]pyridazines (3a, b, 5), 3-alkyl- and 1-alkyl-4-aryl-1,2-dihydro-2-oxopyrido[2,3-d]pyridazines (4b, 6) as well as ethyl 4-aryl-1,2-dihydro-2-oxopyrido[2,3-d]pyridazine-3-carboxylates (7a, b) starting from 5-amino-4-pyridazinyl aryl ketones (1a, b) are reported. Considerable variability of the substitution pattern in the pyridine moiety of this bicyclic system is provided by the proposed strategy of annelation of the pyridine ring to a preformed pyridazine nucleus.
高产合成 2-乙
氧基和 2-二
甲基氨基-4-芳基
吡啶并[2,3-d]哒嗪(3a, b, 5)、3-烷基和 1-烷基-4-芳基-1,2-二
氢-2-
氧代
吡啶并[2、3-烷基和 1-烷基-4-芳基-1,2-二
氢-2-
氧代
吡啶并[2,3-d]哒嗪(4b, 6)以及 4-芳基-1,2-二
氢-2-
氧代
吡啶并[2,3-d]哒嗪-3-
羧酸乙酯(7a, b)。 通过将
吡啶环环化到预先形成的
哒嗪核上的拟议策略,该双环体系中
吡啶分子的取代模式具有相当大的可变性。