Compounds of the formula: and salts thereof, wherein Ar1 is a nitrogen, sulfur or oxygen heterocyclic ring; Ar is a phenyl ring or a nitrogen, oxygen or sulfur heterocyclic ring; Ar and Ar1 may be fully substituted or less than fully substituted with H, CH3, lower alkyl, aryl, aralkyl, halo, hydroxy, lower alkoxy, CF3, carboxy, alkylcarboxy, arylcarboxy, alkylcarbalkoxy, alkanoyl, formyl, oxo, nitrilo, amino, aminoalkyl, alkylamine, carboxamide, aryloxy, nitro, sulfonyl, sulfonamide, thio, alkylthio, hydroxyalkyl or oxyalkylcarbalkoxy; X= STR1 of up to 2 carbon atoms in the principal chain and up to a total of 4 carbon atoms, STR2 Z is an alkylene chain containing up to 10 carbon atoms in the principal chain and a total of up to 12 carbon atoms and from 0 to 2 double bonds and the said alkylene chain may be attached to Ar through an oxygen, sulfur or amino nitrogen atom, and when n'=2, one of the R substituents may be halogen on an omega carbon of the alkylene chain Z; when n'=1, R is a substituent attached to one of the carbon atoms of Z selected from the group consisting of =O, OR3, SR3, N(R2)2 and R1, --COR4 and when n'=2 one R is previously defined and the additional R is a substituent attached to one of the carbon atoms of Z selected from the group consisting of =O, OR3, SR3, N(R2)2, --COR4, lactone and halo; R1 is H or CH3 ; R2 is H, lower alkyl, aryl or aralkyl; R3 is H, lower alkyl, lower alkanoyl, aryl, aralkyl or substituted aryl in which the substituent is halo, lower alkyl or lower alkoxy; R4 is OR2 or N(R2)2 ; n=0 or 1; n'=1 to 7; and n"=0, 1 or 2.