Compounds of formula (I) wherein Thi is thiadiazolyl or thiadiazolyl substituted with alcoxy, fluoromethyl, difluoromethyl, trifluoromethyl, 1,1-difluoroethyl, halo, alkyl, cycloalkyl, hydroxyalkyl, or alkoxyalkyl; Y is alkylene bridge of 3-9 carbon atoms; R1 and R2 are each independently chosen from hydrogen, halo, alkyl, alkenyl, amino, alkylthio, hydroxy, hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkylsulfinylalkyl, alkylsulfonylalkyl, alkoxy, nitro, carboxy, alkoxycarbonyl, dialkylaminoalkyl, alkylaminoalkyl, aminoalkyl, difluoromethyl, trifluoromethyl, or cyano; R3 is alkoxycarbonyl, phenyl, alkyltetrazolyl or heterocyclyl chosen from benzoxazolyl, benzathiazolyl, thiadioazolyl, imidazolyl, dihydroimidazolyl, oxazolyl, thiazolyl, oxadiazolyl, pyrazolyl, isoxazolyl, isothiazolyl, furyl, triazolyl, thienyl, pyridyl, pyrimidinyl, pyrazinyl, pyridazinyl, or substituted phenyl, or substituted heterocyclyl wherein the substitution is with alkyl, alkoxyalkyl, cycloalkyl, haloalkyl, hydroxyalkyl, alkoxy, hydroxy, furyl, thienyl, or fluoroalkyl; or a pharmaceutically acceptable salt thereof are effective antipicornaviral agents.