Abstract

We report the synthesis of a new series of 2-oxo-1,2,4,9-tetrahydro-3H-pyrimido[4,5-b]indole derivatives and diethyl 4-hydroxyquinoline-2,3-dicarboxylate starting from ethyl 3-(2-ethoxy-2-oxoethyl)-1H-indole-2-carboxylate. Intramolecular cyclization formed the target ring systems. The key substrates featuring both acyl azide and isocyanate functionalities were prepared from bis(acyl azide) intermediate. The acyl azide functionalities directly connected to methylene groups were regiospecifically converted into urea and urethanes via the reactive isocyanate intermediates. Thermal treatment of urea and urethanes provided the target 2-oxo-1,2,4,9-tetrahydro-3H-pyrimido[4,5-b]indoles. Furthermore, ozonolysis of the starting indolediester substrate and subsequent base treatment to diethyl 4-hydroxyquinoline-2,3-dicarboxylate are described.

We report the synthesis of a new series of 2-oxo-1,2,4,9-tetrahydro-3H-pyrimido[4,5-b]indole derivatives and diethyl 4-hydroxyquinoline-2,3-dicarboxylate starting from ethyl 3-(2-ethoxy-2-oxoethyl)-1H-indole-2-carboxylate. Intramolecular cyclization formed the target ring systems. The key substrates featuring both acyl azide and isocyanate functionalities were prepared from bis(acyl azide) intermediate. The acyl azide functionalities directly connected to methylene groups were regiospecifically converted into urea and urethanes via the reactive isocyanate intermediates. Thermal treatment of urea and urethanes provided the target 2-oxo-1,2,4,9-tetrahydro-3H-pyrimido[4,5-b]indoles. Furthermore, ozonolysis of the starting indolediester substrate and subsequent base treatment to diethyl 4-hydroxyquinoline-2,3-dicarboxylate are described.

中文翻译：

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3-（2-乙氧基-2-氧乙基）-1H-吲哚-2-羧酸乙酯的化学：通过分子内环化反应合成嘧啶基[4,5-b]吲哚和4-羟基喹啉-2,3-二羧酸二乙酯

摘要

我们报告了一个新的2-oxo-1,2,4,9-tetrahydro-3 H -pyrimido [4,5- b ]吲哚衍生物和4-乙基羟基喹啉-2,3-二羧酸二乙酯的合成3-（2-乙氧基-2-氧代乙基）-1 H-吲哚-2-羧酸酯。分子内环化形成目标环系统。由双（酰基叠氮化物）中间体制备同时具有酰基叠氮化物和异氰酸酯官能度的关键底物。直接与亚甲基连接的酰基叠氮化物官能团通过反应性异氰酸酯中间体区域特异性地转化为尿素和氨基甲酸酯。尿素和氨基甲酸酯的热处理提供了目标2-oxo-1,2,4,9-tetrahydro-3 H -pyrimido [4,5- b]吲哚。此外，描述了起始吲哚二酯底物的臭氧分解和随后对4-羟基喹啉-2，3-二羧酸二乙酯的碱处理。

我们报告了一个新的2-oxo-1,2,4,9-tetrahydro-3 H -pyrimido [4,5- b ]吲哚衍生物和4-乙基羟基喹啉-2,3-二羧酸二乙酯的合成3-（2-乙氧基-2-氧代乙基）-1 H-吲哚-2-羧酸酯。分子内环化形成目标环系统。由双（酰基叠氮化物）中间体制备同时具有酰基叠氮化物和异氰酸酯官能度的关键底物。直接与亚甲基连接的酰基叠氮化物官能团通过反应性异氰酸酯中间体区域特异性地转化为尿素和氨基甲酸酯。尿素和氨基甲酸酯的热处理提供了目标2-oxo-1,2,4,9-tetrahydro-3 H -pyrimido [4,5- b]吲哚。此外，描述了起始吲哚二酯底物的臭氧分解和随后对4-羟基喹啉-2，3-二羧酸二乙酯的碱处理。