Thiadiazoles and their use as antipicornaviral agents

A compound of formula;

• ##STR11## wherein:
• Thi is thiadiazolyl or thiadiazolyl substituted with alkoxy, fluoromethyl, difluoromethyl, trifluoromethyl, 1,1-difluoroethyl, halo, alkyl, cycloalkyl, hydroxyalkyl, or alkoxyalkyl;
• Y is an alkylene bridge of 3-9 carbon atoms;
• R.sub.1 and R.sub.2 are each independently chosen from hydrogen, halo, alkyl, alkenyl, amino, alkylthio, hydroxy, hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkylsulfinyl alkyl, alkylsulfonylalkyl, alkoxy, nitro, carboxy, alkoxycarbonyl, dialkylaminoalkyl, alkylaminoalkyl, aminoalkyl, difluoromethyl, trifluoromethyl, or cyano;
• R.sub.3 is alkoxycarbonyl, alkyltetrazolyl, phenyl, or a heterocycle chosen from imidazolyl, dihydroimidazolyl, pyrazolyl, furyl, triazolyl, thienyl, 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.