Carbon Dioxide → HCID 54211819, compound

Participants

Reaction Steps

Phenyllithium (45 ml of a 2.3 M solution in 7:3 benzene-ether) in added to a dry-ice-cooled, stirring solution of diphenyl N-benzylidene-aminomethylphosphonate (35.1 g) in anhydrous tetrahydrofuran (500 ml). After having been stirred for 15 minutes at -78° under a nitrogen atmosphere, the solution is treated dropwise over 1 hour with p-nitrobenzyl chloroformate (10.8 g) in tetrahydrofuran (100 ml). The resulting solution is stirred an additional 2 hours at -78°, then allowed to warm to 5° over a period of 30 minutes. Evaporation of the solvent under reduced pressure leaves a residue which is partitioned between ethyl ether (500 ml) and 0.5 pH 3 phosphate buffer (200 ml). The aqueous phase is separated and extracted with ethyl ether (2 × 100 ml). The combined ethereal solution is washed with saturated brine, dried over magnesium sulfate, filtered, and concentrated in vacuo. Chromatography of the residue on silica gel affords p-nitrobenzyl N-benzylidene-α-amino-diphenylphosphonoacetate as well as starting material.

Provenance & Evidence