Using l-Keto-2-carboxybenzenes as Substrates

These substrates afford 4-alkyl(or aryl)-l(2//)-phthalazinones. The examples that follow are so numerous that they have been divided into groups according to the type of hydrazine used as synthon. 

2-(5-Ethyl-2-thenoyl)-3,4,5,6-tetrahydrobenzoic acid (69) gave 4-(5-ethylthien-2-yl)-5,6,7,8-tetrahydro-l(2fl)-phthalazinone (70) (H2NNH2 H2O, EtOH, 

With Functionally C-Substituted Alkyl- or Arylhydrazines as Synthons 

2- t-Toluoylbenzoic acid (81) with p-nitrophenylhydrazine gave 2-p-nitro-phenyl-4- -tolyl-l(2//)-phthalazmone (82) (HCl, EtOH, H2O, reflux, 3h  

4-Diethoxybenzoyl)-l,2,3,6-tetrahydrobenzoic acid (83) with p-hydrazino-benzoic acid gave 2-p-carboxyphenyl-4-(3,4-diethoxyphenyl)-4a,5,8,8a-tetra- 

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