Synthesis of 5,8-dihydro-5-oxo-2-(3- or 4-pyridinyl)-pyrido[2,3-<i>d</i>]pyrimidine-6-carboxylic acids and the reinvestigation of the thermal cyclization of diethyl (2-hydroxy-4-pyrimidinyl)amino-methylenemalonate
作者:Baldev Singh、George Y. Lesher
DOI:10.1002/jhet.5570190671
日期:1982.11
Diethyl [2-(3- or 4-pyridinyl)-4-pyrimidinyl]aminomethylenemalonates 5 prepared by the reaction between 2-(3- or 4-pyridinyl)-4-pyrimidinamines 3 and diethyl ethoxymethylenemalonate (4) were thermally cyclized to afford ethyl 5,8-dihydro-5-oxo-2-(3- or 4-pyridinyl)pyrido[2,3-d]pyrimidine-6-carboxylates 6. The later were alkylated with ethyl iodide and then saponified to give 5,8-dihydro-8-ethyl-5-oxo-2-(3-
二[2-(3-或4-吡啶基)-4-嘧啶基〕aminomethylenemalonates 5由2-(3-或4-吡啶基)之间的反应来制备-4- pyrimidinamines 3和二乙基乙氧基亚甲基(4)进行热环化,得到5,8-二氢-5-氧-2-(3-或4-吡啶基)吡啶[2,3 - d ]嘧啶-6-羧酸乙酯6。后者用碘乙烷烷基化,然后皂化,得到5,8-二氢-8-乙基-5-氧代-2-(3-或4-吡啶基)吡啶基- [2,3 - d ]嘧啶-6-羧基酸2。(2-羟基-4-嘧啶基)氨基-亚甲基丙二酸二乙酯的热环化反应(8)得到1,6-二氢-4,6-二氧代-4 H-嘧啶基乙基[1,6-一个]嘧啶-3-羧酸甲酯(10)代替乙基-5,8-二氢-2-羟基-5-氧代吡啶并[2,3- d ]嘧啶-6-羧酸甲酯(9如前面权利)。