In the title compound, C(14)H(10)Cl(2)INO(3)S, the dihedral angle between the benzene rings is 52.13 (10)°. In the crystal, the components are linked by pairs of N-H⋯O(sulfon-yl) hydrogen bonds into centrosymmetric dimers.

In the title compound, C(17)H(20)ClFN(2)O(3), the dihedral angle between the pyridazine and benzene rings is 41.37 (10)°. In the crystal, there are no significant intermolecular interactions present. The terminal -CH(2)F group is disordered over two sets of sites with an occupancy ratio of 0.737 (2):0.263 (2).

In the title compound, C(18)H(13)ClFN(3)O(2), the pyrrolidine ring adopts an envelope conformation and the planar part is rotated by 4.3 (6)° from the plane of the benzene ring and is almost perperdicular both to the diazo-acetyl unit [dihedral angle = 78.93 (7)°] and the phenyl ring [dihedral angle = 86.07 (7)°]. In the crystal, mol-ecules are linked into a three-dimensional framework by C-H⋯O...

The compound 2-((1,3-dimethyl-1H-pyrazol-5-yl)(methyl)carbamoyl)benzene-diazonium hydrogen sulfate (10) was reacted with copper sulfate and sodium chloride, in the presence of ascorbic acid as reducing agent, to afford a mixture of the chlorinated epimers 4'-chloro-2,2',5'-trimethyl-2',4'-dihydrospiro[isoindoline-1,3'-pyrazol]-3-one (18) and (19), the epimers 4'-hydroxy-2,2',5'-trimethyl-2',4'-...