citrate dihydrochloride edetate edisylate estolate esylate fumarate gluceptate gluconate glutamate glycollylarsanilate hexylresorcinate hydrabamine hydrobromide hydrochloride hydroxynaphthoate iodide isethionate lactate lactobionate laurate malate maleate mandelate mesylate methylbromide methylnitrate methylsulfate monopotassium maleate mucate napsylate nitrate n methylglucamine oxalate pamoate embonate palmitate pantothenate phosphate diphosphate polygalacturonate potassium salicylate sodium stearate subacetate succinate tannate tartrate teoclate tosylate triethiodide trimethylammonium and valerate other salts which are not pharmaceutically acceptable may be useful in the preparation of compounds of this invention and these form a further aspect of the invention a preferred aspect of the present invention is a compound of formula i wherein r 1 is h another preferred aspect of the present invention is a compound of formula i wherein r 1 is substituted aryl or substituted heteroaryl wherein each substituent is independently selected from the group consisting of aryl halo and u2014 or 4 and r 4 is aryl or haloaryl another preferred aspect of the present invention is a compound of formula i wherein r 1 is u2014 c o n h r 2 and r 2 is substituted aryl wherein each substituent is independently selected from the group consisting of cyano halo nitro and haloalkyl a further aspect of the present invention is a compound of formula i wherein said compound is selected from and salts and solvates thereof wherein r 5 and r 6 are independently selected from the group consisting of hydrogen halo and u2014 or 4 r 4 is aryl or haloaryl and r 7 is cyano.