Synthesis of pyrazolyl-thiazoles for studying their antiviral activity against animal viruses

Acid chloride (II) of N-phthaloyl-glycine (I) on reaction with thiasemicarbazide afforded 2-hydrazino-4-phthalimido-thiazole (III) in 65% yield which on condensation with acetyl acetone yielded 4-phthalimido2-[3,5-dimethyl-1H-pyrazol-1-yl)-thiazole(IV) in 60% yield. Interaction of (IV) with amidoalcohols resulted in 4-phthalimido-5-aralkylamidoalkyl-[3,5-dimethyl-1H-pyrazol-1-yl]-thiazoles (V) in the yields varying from 63 to 72 percents. Compounds (V) were evaluated for their antiviral activity against two animal viruses viz., Japanese encephalitis virus (JEV) and Herpes simplex virus type-I.