Triphenylphosphine → 3-{[Bis(benzyloxy)phosphoryl]oxy}propyl 6-bromo-1-ethyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate

Participants

Reaction Steps

3-Hydroxypropyl 6-bromo-1-ethyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate (Intermediate 24, 100 mg, 0.28 mmol), dibenzyl hydrogen phosphate (124 mg, 0.44 mmol) and triphenylphosphine (367 mg, 1.4 mmol) was dissolved in tetrahydrofuran (15 mL). Diisopropyl azodicarboxylate [DIAD] (281 mg, 1.40 mmol) was added and the mixture was stirred for 4 h at room temperature. The reaction mixture was concentrated under reduced pressure and water (100 mL) was added. The aqueous mixture was extracted with ethyl acetate (2×100 mL) and the combined organic layers were dried over anhydrous sodium sulphate, filtered and concentrated under reduced pressure to give a crude compound. The crude compound was purified by flash column chromatography over silica gel (0-50% ethyl acetate/petroleum ether) to afford 80 mg (47%) of 3-{[bis(benzyloxy)phosphoryl]oxy}propyl 6-bromo-1-ethyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carboxylate

Provenance & Evidence