Triethylamine → Methyl cis-1-(2,4-Dimethoxybenzyl)-3-phenoxyacetamido-4-oxo-2-azetidinecarboxylate

Beteiligte Stoffe

Reaktionsschritte

The crude amine prepared in Example 2 from 10 g of the azido precursor is taken up in 100 ml of anhydrous methylene dichloride and is cooled to 0° in an ice bath. To this solution is added 4.32 ml (0.0312 mol) of triethylamine followed by the slow addition of a solution of 5.32 g (0.0312 mol) of phenoxyacetyl chloride in 40 ml of methylene dichloride. The mixture is stirred at 0° for 1 hr. then poured into a separatory funnel and extracted successively with water, aqueous HCl, aqueous NaHCO3, brine and is dried over anhydrous magnesium sulfate. After filtration the solvent is removed in vacuo to give a yellow solid. This material is partially dissolved in ether, cooled to -25°, and filtered to afford 11.2 g (84%) of the title product as a white solid which is one spot on tlc: benzene-ethyl acetate (1:1), silica gel, R 0.38. An analytical sample, mp 115.5°-116.0°, is obtained by recrystallization from ethyl acetate-hexane.

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