pyridine 3 4 5 tricarboxylate triethyl pyridine 3 4 5 tricarboxylate tetramethyl pyridine 2 3 4 5 tetracarboxylate tetraethyl pyridine 2 3 4 5 tetracarboxylate and 5 fluoro trimethyl pyridine 2 3 4 tricarboxylate preferred quinoline monoesters include methyl quinoline 3 carboxylate ethyl quinoline 3 carboxylate methyl quinoline 4 carboxylate ethyl quinoline 4 carboxylate methyl quinoline 5 carboxylate ethyl quinoline 5 carboxylate methyl quinoline 6 carboxylate ethyl quinoline 6 carboxylate methyl quinoline 7carboxylate ethyl quinoline 7 carboxylate methyl quinoline 8 carboxylate ethyl quinoline 8 carboxylate 3 bromo methyl quinoline 4 carboxylate 3 5 dichloro methyl quinoline 4 carboxylate 3 5 6 trifluoro methyl quinoline 4 carboxylate 3 5 6 7 tetrabromo methyl quinoline 4 carboxylate and 3 5 6 7 8 pentachloro methyl quinoline 4 carboxylate illustrative quinoline diesters include dimethyl quinoline 3 4 dicarboxylate diethyl quinoline 3 5 dicarboxylate dimethyl quinoline 3 6 dicarboxylate and diethyl quinoline 3 7 dicarboxylate illustrative quinoline triesters include trimethyl quinoline 3 4 5 tricarboxylate triethyl quinoline 3 4 6 tricarboxylate trimethyl quinoline 3 4 7 tricarboxylate and triethyl quinoline 3 4 8 tricarboxylate other illustrative quinoline esters include tetramethyl quinoline 3 4 5 6tetracarboxylate tetraethyl quinoline 3 4 5 7 tetracarboxylate pentamethyl quinoline 3 4 5 6 7 pentacarboxylate and pentaethyl quinoline 3 4 5 6 8 pentacarboxylate the most preterred compounds of the formula i are isonicotinic acid picolinic acid nicotinic acid dimethyl pyridine 2 3 dicarboxylate dimethyl pyridine 2 5 dicarboxylate dimethyl pyridine 3 5 dicarboxylate and methyl quinoline 4 carboxylate the pyridine based compound is added to water.