4-Methylmorpholine → (3S)-alpha-[[(2-Oxo-3-azetidinyl)amino]carbonyl]benzeneacetic acid, phenylmethyl ester

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Reaction Conditions

Reaction Steps

The above azetidinone (3.0 g) is dissolved in 100 ml of dimethylformamide. The solution is cooled to 0° C. and 4.5 g of N-methylmorpholine is added followed (dropwise) by 10.8 g of α-(chlorocarbonyl)benzeneacetic acid, phenylmethyl ester in 50 ml of acetonitrile with stirring. The mixture is stirred for about 16 hours at 5° C. The solvent is distilled off in vacuo and 100 ml of water is added to the residue. The aqueous suspension is extracted twice with 100 ml portions of methylene chloride. The organic layers are combined, washed with sodium bicarbonate, 2N phosphoric acid and water, dried with sodium sulfate, filtered and evaporated to dryness. The residue is crystallized with ethyl acetate and petroleum ether, yielding 8.7 g, melting point 164°-166° C.

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