Acetic Acid → Oseltamivir

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

To a solution of 50.0 g (0.147 mol) of 30, 300 mL of EtOH, 50 mL of water and 0.09 g of acetic acid in a nitrogen-purged 1000 mL glass reactor fitted with a mechanical stirrer, a condenser, and a 250 mL dropping funnel was added a solution of 31.4 g (0.155 mol) of tributylphosphine in 150 mL EtOH at a temperature of 5° C. (+/−5° C.) over a period of 30-90 min. The reaction temperature was maintained at this temperature by slight cooling of the jacket (ca. 3° C.). The funnel was rinsed with 20 mL of EtOH. The clear reaction mixture was stirred for additional 90 min at 5° C. (+/−5° C.) under slight jacket cooling. Subsequently the temperature was raised within 30-60 min to 20-25° C. and the solution was stirred for another 3 h (nitrogen evolution). After the reaction was finished (HPLC assay) 0.18 g of acetic acid were added to the clear solution and the mixture was concentrated to near dryness under reduced pressure (300 to 50 mbar) at a maximum temperature of 60° C. and a maximum jacket temperature of 75° C. The oily residue (80-100 mL) was diluted with 160 mL of EtOH, the resulting solution was then again concentrated following the method described above. The oily residue was dissolved in EtOH up to a volume of 250 mL. The water content of this solution was determined by KF(Karl Fischer) titration to be less than 1.0% wt. %. Yield: 44.4 g (97% area by HPLC) of 32 in EtOH solution.

Herkunft & Nachweise