Pyridazines; XXX<sup>1,2</sup>. A Novel Approach to Pyrido[2,3-<i>d</i>] pyridazines by Annelation of the Pyridine Ring to the 1,2-Diazine System
作者:N. Haider、G. Heinisch
DOI:10.1055/s-1986-31809
日期:——
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。