论文信息 - A one-pot synthesis of coumarins from dipotassium O-methoxybenzylidenemalonates

A one-pot synthesis of coumarins from dipotassium O-methoxybenzylidenemalonates

o-Methoxybenzylidenemalonates 1, which are available from o-methoxybenzaldehydes and diethyl malonate, were hydrolysed to the dipotassium malonates 2. Treatment of the salts 2 with trifluoroacetic acid–trifluoroacetic anhydride gave the title coumarins by a demethylative ring-closure reaction in 60–80% yield.

O. Hormi | C. Peltonen | Riitta Bergström

[1] R. Harvey,et al. A new coumarin synthesis and its utilization for the synthesis of polycyclic coumarin compounds with anticarcinogenic properties , 1988 .

[2] R. Tapia,et al. Synthesis of 3-Carboxycoumarins from O-Methoxybenzylidene Meldrum's Acid Derivatives , 1988 .

[3] O. Hormi,et al. Flavone-3-carboxylic acids, esters, and related compounds from .beta.-(chloroarylidene)malonates , 1987 .

[4] J. Hepworth,et al. 2.24 – Pyrans and Fused Pyrans: (iii) Synthesis and Applications , 1984 .

[5] Stewart A. Brown,et al. The natural coumarins : occurrence, chemistry, and biochemistry , 1982 .

[6] G. Kraus,et al. Michael additions in anhydrous media. A novel synthesis of oxygenated coumarins , 1979 .

[7] E. Campaigne,et al. Cyclization of ylidenemalononitriles. VIII. Synthesis of coumarins from o‐methoxybenzylidenemalonitriles , 1975 .

[8] Alan C. Duckworth. Substituted Malonic and Trifluoroacetic-Malonic Anhydrides and Their Pyrolysis to Ketenes , 1962 .

[9] F. Francis,et al. Über eine neue Methode zur Darstellung von Derivaten der α‐Cyanacrylsäure , 1911 .

[10] E. Knoevenagel. Condensationen zwischen Malonester und Aldehyden unter dem Einfluss von Ammoniak und organischen Aminen , 1898 .