illustrative inorganic acids which form suitable salts include but are not limited to hydrogen chloride hydrogen bromide sulphuric and phosphoric acids illustrative organic acids which form suitable salts include but are not limited to acetic acid lactic acid malonic acid succinic acid glutaric acid fumaric acid malic acid tartaric acid citric acid ascorbic acid maleic acid benzoic acid phenylacetic acid cinnamic acid methane sulfonic acid salicylic acid and the like the term u201c acid addition salt u201d as used herein also comprises solvates which the compounds and salts thereof are able to form such as for example hydrates alcoholates and the like these salts also include salts useful for the chiral resolution of racemates the expression u201c base addition salt u201d includes any non toxic base addition salts that the compound of formula i can form suitable base salts include but are not limited to those derived from inorganic bases such as aluminum ammonium calcium copper iron lithium magnesium manganese potassium sodium and zinc salts in particular sodium and ammonium salts further examples of organic base addition salt include salts of trialkylamines such as triethyl amine and trimethyl amine and choline salts the present invention relates to estrone c 17 ketimine c 15 thiazole compound having a formula i i a r2 and r4 are each independently selected from the group consisting of h halogen c 1 6 alkyl c 1 3 haloalkyl.