Triethylamine → 5'-O-[N-{N-(Nalpha,Nepsilon-di benzyloxycarbonyllysyl)alanyl}isoleucyl]-5-fluorouridine

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Reaction Steps

0.46 Gram of 5'-O-(N-alanylisoleucyl)-5-fluorouridine hydrochloride obtained in Example 4 was dissolved in dimethylformamide (30 ml), and 1.42 g (3.42 mmol) of Nα,Nε -di-benzyloxycarbonyllysine and 0.90 g (5.52 mmol) of diethylphosphoryl cyanide were then added. To this solution was added under ice-cooling a solution of 1.30 g (12.9 mmol) of triethylamine in dimethylformamide, and the mixture was stirred for 1 hour at room temperature, allowed to stand overnight at room temperature and concentrated under reduced pressure. The residue was subjected to separation/purification by way of silica gel column chromatography (5×20 cm; a linear gradient of chloroform containing 3%→6% methanol) whereby 1.20 g (45.9%) of 5'-O-[N-{N-(Nα,Nε -di benzyloxycarbonyllysyl)alanyl}isoleucyl]-5-fluorouridine was obtained as a colorless powdery solid.

Provenance & Evidence