Water → 3-Nitrophthalic anhydride

Reaction equation

[N+:1]([C:4]1[CH:13]=[CH:12][CH:11]=[C:10]2[C:5]=1[C:6](=[O:15])[NH:7][NH:8][C:9]2=[O:14])([O-:3])=[O:2].[OH2:16]>C(O)(=O)C>[N+:1]([C:4]1[CH:13]=[CH:12][CH:11]=[C:10]2[C:9]([O:16][C:6](=[O:15])[C:5]=12)=[O:14])([O-:3])=[O:2].[OH2:2].[NH2:7][NH2:8]

Participants

Procedure

where M is Li, Na, K wherein 5-nitro-2,3-dihydrophthalazine-1,4-dione is solved in water solution of MOH, where M has the above mentioned meaning, with forming solution of 5-nitro-2,3-dihydrophthalazine-1,4-dione alkaline salt which is catalytically transformed in 5-amino-2,3-dihydrophthalazine-1,4-dione salt at the temperature of 40-90° C. by means of hydrogen under the pressure of 1-4 MPa at the presence of a transition metal catalyst (Pt, Pd) on active carbon, and separation of 5-amino-2,3-dihydrophthalazine-1,4-dione crystalline salt is performed by dilution of the water solution with lower alcohol or cyclic lower ether while cooling to the temperature −5° C. to −15° C., providing that there is used 5-nitro-2,3-dihydrophthalazine-1,4-dione obtained in the reaction of 3-nitrophthalic acid anhydride with hydrazine hydrate in anhydrous acetic acid at the temperature 100-110° C. with distilling the mixture of acetic acid and water off.