A solution of 4-(3-formyl-4-nitrophenyl)oxybutyric acid chloride was added dropwise to a solution of N-cyclohexyl glycinamide (7.8 g) and sodium carbonate (6.90 g) in aqueous tetrahydrofuran cooled to 5° C. The reaction was stirred at room temperature for 1 hour, then extracted with ethyl acetate. The organic extract was washed with saturated sodium bicarbonate three times, 3×1M HCl and 2×brine, filtered and the solvent evaporated to give 2-(N-cyclohexyl-4-(3-formyl-4-nitrophenyl)oxybutyramidyl)acetamide as a solid, m.p. 104°-105° C. Similarly, treatment of cyclohexyl R7R8 -N-substituted acetamides from Preparation 2 gives the corresponding 2-(N-cyclohexyl-4-(3-nitro-4-formylphenyl)oxybutyramidyl-R7R8 -N-substituted acetamides.
