Chloride → HCID 178520628, compound

Participants

Reaction Conditions

Reaction Steps

Dry phosphinic acid (100 g, 1.52 mol) was dissolved in 100 ml of chloroform and treated with triethylamine (155 g, 1.52mol). The mixture was evaporated and transferred to a three liter flask, containing 750 mL of chloroform. The solution was stirred by means of a mechanical stirrer and the flask cooled to 0° C. The clear solution was treated with triethylamine (277 g, 2.72 mol) followed by trimethylsilyl chloride (281 g, 2.58 mol). Once addition of trimethylsiyl chloride was complete dibenzyl 2-methylenepentanedioate (2) in 150 mL of chloroform was added dropwise over 20 minutes. The low temperature bath was removed and the mixture warmed to room temperature. After 6 hours the thick slurry was filtered and the filtrate cooled to 0° C. The filtrate was then quenched with 5% hydrochloric acid and the organic layer removed. The aqueous layer was extracted with chloroform, the organics combined, dried (MgSO4) and evaporated under reduced pressure to give 55 g of 2,4-di(benzyloxycarbonyl)butylphosphinic acid (6) as a light yellow liquid. The liquid was purified by flash chromatography and eluted using 3:1 hexanes/ethyl acetate containing 5% trifluoroacetic acid to give 40 g (7%) of the desired product. Rf 0.28(3:1 Hex./EtOAc 5% TFA);

Provenance & Evidence