5,6-二氢-5-氧杂-1,3-二氮杂菲衍生物的合成

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

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.

From starting material 2,3-dihydro-3-oxobenzo[c]-α-pyran （1）, 3-acetyl-2,3-dihydro-3-oxobenzo- [c]-a-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-oxobenzo[c]-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.