Reactions of Phthalazine Amides

The hydrolysis of phthalazinecarboxamides to phthalazinecarboxylic acids has been exemplified in Section 14.1.1. Some other reactions are illustrated in the following classified examples. 

Note This has been done indirectly as a one-pot procedure by hydrolysis and decarboxylation. 

4-(a-Benzamido-a-hydrazinocarbonyImethyl)-1 (27/)-phthalazinone (74) gave 4-aminomethyl-l(27/)-phthalazinone (75) (HCl then NaOH for details, see original note additional deacylation). 

Note Carbohydrazides, rather than carboxamides, are prone to the formation of such derivatives. 

2-Hydrazinocarbonylmethyl-4-phenyl-l(2//)-phthalazinone (78) wifli p-bromo-benzaldehyde gave 2-[(p-bromobenzyIidenehydrazinocarbonyl)methyl]-4-phenyl-l(277)-phthalazinone (79) (reactants, trace AcOH, EtOH, reflux, 2h 70%) or with o-hydroxyacetophenone gave 2-[(o-hydroxy-a-methylbenzyli-denehydrazinocarbonyl)methyl] -4-phenyl-1 (277)-phthalazinone (80) (likewise 80%) other aldehydes or ketones produced analogous products. 

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