5,6-二氢-5-氧杂-1,3-二氮杂菲衍生物的合成

以2,3-二氢-3-氧代-1,3-苯并(c)-α-吡喃(1)为起始原料, 在氢化钠作用下, 通过与羰基α-氢的Claisen缩合反应, 得到3-乙酰基-2,3-二氢-3-氧代-1,3-苯并(c)-α-吡喃(2), 所得β-二酮与脲、硫脲和脒衍生物分别进行缩合关环, 生成5,6-二氢-5-氧杂-1,3-二氮杂菲衍生物3和4. 在相同的条件下, 吡喃酮1与草酸二乙酯进行缩合反应, 给出3-乙氧乙二酰 基-2,3-二氢-3-氧代-1,3-苯并(c)-α-吡喃(5), 选择3-氨基吡唑、2-氨基咪唑、3-氨基三唑、2-氨基苯并咪唑和3,5-二氨基吡唑-4-偶氮苯与5缩合, 分别环合成5,6-二氢-5-氧杂-1,3-二氮杂菲并和五元含氮杂环衍生物6～10. 所合成的新化合物均经核磁共振光谱、红外光谱及元素分析证明其结构.

Synthesis of 5,6-Dihydro-5-oxo-1,3-penanthroline Derivatives

From starting material 2,3-dihydro-3-oxobenzoc]-α-pyran (1), 3-acetyl-2,3-dihydro-3-oxobenzo- c]-α-pyran (2) was obtained via condensation of α'-hydrogen of 1 with the ethoxy of ethyl acetate in the presence of sodium hydride. This β-diketone condensed with urea, thiourea or amidine derivatives to form 5,6-dihydro-5-oxa-1,3-penanthroline derivatives 3 and 4, respectively. The condensation of 1 with diethyl oxalate in the same condition afforded 3-ethoxyoxalyl-2,3-dihydro-3-oxobenzoc]-α-pyran (5). 2-Aminoimidazole, 3-aminopyrazole, 3-aminotriazole, 2-aminobenzoimidazole and 3,5-diamino-4- phenylazopyrazole were condensed with β-ketoester 5 to generate 5,6-dihydro-5-oxa-1,3-penanthrolinoe further fused derivatives 6～10, respectively. The structures of all these compounds were characterized by elemental analysis, IR and ¹H NMR spectra.