Sodium Carbonate → Oseltamivir

Participants

Reaction Steps

A stirred solution of oseltamivir phosphonate 100 mg, in 50 mL DCM was treated with 50 mL aqueous Na2CO3 (50 mg). The white solution was stirred over a period of 45 minutes at room temperature. The combined aqueous and organic layers were extracted with dichloromethane (100 mL) and the organic phase was dried over Na2SO4. The combined organic phases were evaporated in a rotary evaporator to yield the product oseltamivir as a liquid, which was used without further purification in the next step. Oseltamivir was reacted with ethylene sulphide in dichloromethane in a sealed tube and heated at 65 degrees centigrade for 6 hours. The reaction was then cooled to room temperature and evaporated in a rotary evaporator to yield the product, which was purified by silica column chromatography (hexane/dichloro methane 20:80 ratio). Ethylene sulphide derivative of oseltamivir and fluorescein-5-maleimide was added to 5 mL of DMF. The reaction mixture was stirred for 24 hours at room temperature and concentrated under vacuum. The crude product was purified by preparative RP-HPLC using aqueous CH3CN. Acetonitrile was removed under vacuum, and pure fractions were freeze-dried to yield oseltamivir-alkyl-fluorescein-5-maleimide as an orange solid.

Provenance & Evidence