Scheme 2. Synthetic strategy for the preparation of pyrazole conjugated rhodanine carboxylic acids (13a–l). aReagents and conditions: (a) semicarbazide hydrochloride (1.1 equiv.), NaOAc (1.3 equiv.), EtOH, reflux; (b) POCl3 (10 equiv.), DMF, reflux; (c) CS2 (1.2 equiv.), KOH (1 equiv.), water, r.t.; (d) potassium chloroacetate (1 equiv.), 2 N HCl until pH 2, 90 °C; (e) β-alanine (2 equiv.), AcOH, reflux. 
= 4-OCH3, 4-NO2, 3,5-F2; 
= H, CH3, CH2–C6H5, 3-indolylmethyl. * Further for the substitution pattern see Table 2.
