1,2-Dichloroethane → 1-[4-(Thiazol-2-yl)-phenyl]-4(S)-hydroxy-2-(tert-butoxycarbonyl)amino-5(S)-N-(N-methoxycarbonyl-(L)-iso-leucyl)amino-6-phenyl-2-azahexane

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Reaction Steps

Under a nitrogen atmosphere, 938 mg (4.96 mmol) of N-methoxycarbonyl-(L)-iso-leucine, 1.78 g (9.3 mmol) of EDC and 838 mg (6.2 mmol) of HOBT are dissolved in 13.7 ml of DMF. After 30 min, 2.6 ml (18.6 mmol) of TEA are added and then a solution of 1.45 g (3.1 mmol) of 1-[4-(thiazol-2-yl)-phenyl]-4(S)-hydroxy-2-(tert-butoxycarbonyl)amino-5(S)-amino-6-phenyl-2-azahexane (Example 17b) in 28 ml of DMF is added dropwise thereto. After 3 hours the reaction mixture is concentrated by evaporation; the residue is taken up in ethyl acetate and a small amount of THF and washed with water, sat. NaHCO3 solution, water and brine. The aqueous phases are extracted with ethyl acetate; the combined organic phases are dried over Na2SO4 and concentrated by evaporation. Column chromatography (SiO2 ; methylene chloride/THF 5:1) and stirring from ethyl acetate/DIPE yield the title compound: HPLC20-100 : tRet =16.3; FAB MS (M+H)+ =640.

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