A reaction of diazosulphonates derived from beta-naphthol-l-sulphonic acid; the phthalazine reaction with bases not containing a nitro-group; derivatives of halogenobenzene-2-naphthol-l-diazosulphonates.
D009284:Naphthols; D010793:Phthalazines; D013451:Sulfonic Acids