Alkoxy methylenemalonic ester

The Gould-Jacobs reaction is a sequence of the following reactions (1) condensation of an arylamine 1 with either alkoxy methylenemalonic ester or acyl malonic ester 2 providing the anilidomethylenemalonic ester 3 (2) cyclization of 3 to the 4-hydroxy-3-carboalkoxyquinoline 4 (3) saponification to form acid 5, and (4) decarboxylation to give the 4-hydroxyquinoline 6. All steps of this process will be described herein with emphasis on the formation of intermediates like 3 and 4. 

The condensation reaction of aniline with alkoxy-methylenemalonic esters, followed by cyclization to 4-hydroxy-3-carbalkoxy quinolines, is described as the Gould-Jacobs reaction. The reaction can use various derivatives of methylene malonic ester such as keto-malonic esters, malonitriles, malonamides, and Meldrum acid. 

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