phenyl ring include halo and haloalkyl the most preferred substituent is halo the preferred substitution pattern on the phenyl ring is ortho or meta the most preferred substitution pattern on the phenyl ring is meta in the above structure r 1 is co 2 h c o nhoh co 2 r 7 ch 2 oh so 2 r 7 c o nhr 7 c o nhs o 2 r 7 or tetrazole wherein r 7 is alkyl heteroalkyl monocyclic carbocyclic aliphatic ring monocyclic heterocyclic aliphatic ring monocyclic aromatic ring or monocyclic heteroaromatic ring preferred r 7 is methyl ethyl and isopropyl preferred r 1 is co 2 h c o nhoh co 2 r 7 c o nhso 2 r 7 and tetrazole most preferred r 1 is co 2 h and co 2 r 7 in the above structure w is o nh s s o s o 2 or ch 2 m wherein m is an integer from 0 to about 3 preferred w is o and ch 2 m most preferred w is ch 2 1 in the above structure r 2 is h and r 3 is h or lower alkyl or r 2 and r 3 together form a covalent bond in the above structure r 4 is h alkyl heteroalkyl monocyclic carbocyclic aliphatic ring monocyclic heterocyclic aliphatic ring monocyclic aromatic ring or monocyclic heteroaromatic ring provided that when each r 5 and r 6 is h r 4 is other than methyl preferred r 4 is h and lower.