. . "ocarbonylalkyl, heteroarylalkoxyalkyl, heteroaryloxyalkyl, heteroarylthioalkyl, aralkoxy, aralkylthio, heteroaralkoxy, heteroaralkylthio, heteroarylalkylthioalkyl, heteroaryloxy, heteroarylthio, arylthioalkyl, aryloxyalkyl, arylthio, aryloxy, aralkylthioalkyl, aralkoxyalkyl, aryl and heteroaryl; wherein R4 is a radical selected from hydrido, alkyl and halo; and wherein R13 and R14 are independentl" . .