Cyclohexanecarboxylic acid (I) is condensed with 1-bromo-2-ethylbutane (II) by means of lithium diisopropylamide (LDA) (NaH can also be added ) in THF or THF/cyclohexane to afford derivative (III). Treatment of carboxylic acid (III) with oxalyl chloride in CH2Cl2 (a small amount of DMF can be added) yields acid chloride (IV), which is then coupled with bis(2-aminophenyl) disulfide (V) in pyridine to provide disulfide derivative (VI). Reduction of the disulfide bond of (VI) with PPh3 in dioxane/H2O gives benzenethiol (VII), which is finally coupled with isobutyryl chloride (VIII) in pyridine/CHCl3 to furnish the target compound.