P,P,P′,P′-Tetraethyl P,P′-ethylidenebis[phosphonate] → HCID 131731112, compound

Participants

Reaction Conditions

Reaction Steps

As shown in FIG. 8, 2-Ethyl-3-iodo-imidazo[1,2-α]pyridine 72 (Example 28) (5.0 g, 18.34 mmol) in anhydrous THF (80 mL) was stirred at −78° C., under argon, then n-BuLi (2.5 M, 14.7 mL, 36.76 mmol) in hexanes was added slowly, keeping the temperature below −70° C. The resulting mixture was stirred for 10 minutes, then tetraethyl ethene-1,1-bisphosphonate 3 (5.52 g, 18.38 mmol) in anhydrous THF (20 mL) was added slowly , keeping the temperature below −70° C. The reaction mixture was stirred for an additional 10 min, cooled to room temperature, then quenched with saturated NH4Cl (100 mL). The mixture was then extracted with CH2Cl2 (200 mL×3) and the organic phase washed with water (200 mL×2). The resultant organic phase was then dried (NaSO4), concentrated under reduced pressure and purified on silica gel (CombiFlash, EtOAc/MeOH elution) and HPLC to afford [(diethoxy-phosphoryl)-(2-ethyl-imidazo[1,2-α]pyridin-3-yl)-methyl]-phosphonic acid diethyl ester 74 as pale yellow oil with a yield of 900 mg, 11%.

Provenance & Evidence