Using a procedure similar to that of Example 6-D, methyl 4-(2-fluoroethoxy)-2-hydroxybenzoate (5.0 g, 24.75 mmol), trans-4-tert-butoxycarbonylaminocyclohexanol (5.02 g, 24.75 mmol), and triphenylphosphine (1.2 equivalents) in THF (125 mL) is treated with diethyl azodicarboxylate (1.3 equivalents) in THF (25 mL). After having stirred overnight at room temperature, the reaction mixture was heated 8 h at 40-50° C., then stirred overnight at room temperature. The crude product was isolated by elution from silica gel with a gradient of 0 to 40% ethyl acetate in hexane to afford crude methyl 2-(cis-4-tert-butoxycarbonylaminocyclohexyloxy)-4-(2-fluoroethoxy)benzoate (7.30 g), which is used without further purification.
