Chlorambucil → N-(2-{4-[Bis(2-chloroethyl)amino]butanoyloxy}ethyl)-3-pyridinecarboxamide

Beteiligte Stoffe

Reaktionsschritte

Chlorambucil (20 g, 0.0657 mol) was dissolved in 800 mL of dry acetonitrile, then 13.1 g (0.079 mol) of N-(2-hydroxyethyl)-3-pyridinecarboxamide were added. Acetonitrile was added until the solution was clear. The total volume of acetonitrile used at this stage was 850 mL. To the stirred solution, maintained over argon, there were added 1.492 g (0.0723 mol) of dicyclohexylcarbodiimide and 0.802 g (0.0066 mol) of 4-(dimethylamino)pyridine (DMAP). The reaction mixture was stirred overnight at room temperature under dry conditions, and the progress of the reaction was followed by thin layer chromatography. At the end of the reaction period, the solid which formed was removed and washed with 50 mL of cold acetonitrile. The filtrate was evaporated in vacuo at 30° C., and the yellow solid thus obtained was dissolved in a minimum amount (15 mL) of 8:2 chloroform/tetrahydrofuran and applied to a column packed with 900 g of silica gel. The column was eluted with 8:2 chloroform/tetrahydrofuran. The adduct and chlorambucil were eluted within the first 500 mL, and the desired ester was then collected upon evaporation of the eluent under vacuum. The title compound was obtained in 82.7% yield as a yellow solid melting at 73°-75° C. It had the formula ##STR110##

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