Synthesis of pyrazolinylnaphthalic acid derivatives

A method for preparing pyrazolinylnaphthalic acid derivatives of the general formula 10

• wherein Ar1 and Ar2 are selected from the group consisting of unsubstituted or substituted phenyl radicals bearing in the para position substituents selected from the group consisting of an alkylated or acylated oxy or amino group, or a polynuclear aryl radical;
• and
• wherein Ar3 is selected from the group consisting of a substituted N-naphthalimid or 1,8-naphthylene-1′,2′-benzimidazole,
• said method comprising the steps of:
• reacting 4-acetylnaphthalic anhydride with organic reagents through a series of successive transformations resulting in formation of a corresponding ketone;
• treating of said ketone with a chemical selected from the group consisting of phenyl hydrazine or substituted phenyl hydrazine under heating in a solvent;
• and
• separation of the final product by filtration;
• wherein said 4-acetylnaphthalic anhydride is reacted with the corresponding compound selected from the group consisting of aromatic or heterocyclic aldehyde in aqueous alkali medium;
• and
• the formed disodium salt of cinnamoylnaphthalic acid is condensed with an aromatic amine selected from the group consisting of a substituted or unsubstituted aromatic amine obtaining said ketone.