3-[1-(4-Sulfamoylphenyl)-5-p-tolyl-1H-pyrazol-3-yl]propanoic acid and 3-[5-(4-bromophenyl)-1-(4-sulfamoylphenyl)-1H-pyrazol-3-yl]propanoic acid-dichloromethane-diethyl ether-water (2/0.72/1/1).

The syntheses of 3-[1-(4-sulfamoylphenyl)-5-p-tolyl-1H-pyrazol-3-yl]propanoic acid, C(19)H(19)N(3)O(4)S, (I), and 3-[5-(4-bromophenyl)-1-(4-sulfamoylphenyl)-1H-pyrazol-3-yl]propanoic acid-dichloromethane-diethyl ether-water (2/0.72/1/1), 2C(18)H(16)BrN(3)O(4)S.0.72CH(2)Cl(2).C(4)H(10)O.H(2)O, (II), are regiospecific. However, correct identification by spectroscopic techniques of the regioisomer formed is not trivial and single-crystal X-ray analysis provided the only means of unambiguous structure determination. Both structures make extensive use of hydrogen bonding and while compound (I) forms a straightforward unsolvated Z' = 1 structure, compound (II) crystallizes as an unusual mixed solvate, with two crystallographically unique molecules of the pyrazole derivative present in the asymmetric unit. The structure of (II) also features Br...Br interactions.