A procedure similar to that described in Example 2 was repeated, except that 100 mg (0.18 mmoles) of (2S, 4S, 5S)-5-[N-(t-butoxycarbonyl) 3-(4-thiazolyl)-L-alanyl]amino-6-cyclohexyl-4-hydroxy-2-(1-hydroxy-1-methylethyl)-N-methylhexanamide [prepared as described in Example 9(a)], 58 mg (0.20 mmoles) of N-morpholinoacetyl-L-phenylalanine, 0.03 ml (0.20 mmoles) of diethyl cyanophosphate, and 0.08 ml (0.57 mmoles) of triethylamine were used, to obtain 101 mg (yield 77%) of the title compound as a white amorphous substance.
