Tributyl phosphite → 7-[(Phenoxyacetyl)amino]-8-oxo-3-(dibutoxyphosphinyl)-1-azabicyclo[4.2.0]-oct-2-ene-2-carboxylic acid (diphenylmethyl)ester

Beteiligte Stoffe

Reaktionsschritte

A solution of 3-bromo-7-[(phenoxyacetyl)amino]-8-oxo-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid (diphenylmethyl)ester (2 g, 3.6 mmol) in toluene (50 mL) was added tri-n-butyl phosphite (15 mL) and nickel(II)chloride (50 mg, 039 mmol). The reaction was brought to reflux under nitrogen. Each hour, the reaction was cooled and an additional portion of nickel(II)chloride (50 mg, 0.39 mmol) was added. This process was continued for a total of six hours. The reaction was concentrated in vacuo and the residue purified by flash chromatography on silica gel (25%-50% ethyl acetate/hexanes) to provide 7-[(Phenoxyacetyl)amino]-8-oxo-3-(dibutoxyphosphinyl)-1-azabicyclo[4.2.0]-oct-2-ene-2-carboxylic acid (diphenylmethyl)ester (588 mg, 24%):

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