1,2-Dichloroethane → Propanoylamino-5-bromo-1-(4-methoxybenzyl)-4-methyl-2-pyridone

Beteiligte Stoffe

Reaktionsschritte

To a solution of 2-(S)-tbutoxycarbonylamino-3-[4′-(1″-tbutoxycarbonyl-1″-methyl)ethyl]benzene]propanoic acid (3.20 g, 7.88 mmol) in methylene chloride (20 ml,) and DMF (5 mL) at 0° C. were added HOAT (1.07 g) and 1-(4-methoxybenzyl)-5-bromo-4-methyl-3-amino-2-pyridone (2.80 g, 8.67 mmol). EDC (1.66 g) and TMP (1.04 mL) were added, and the mixture was stirred coming to rt overnight. The methylene chloride was evaporated and DMF (25 mL) was added. Additional EDC (0.80 ;), HOAT (0.50 g) and TMP (0.5 mL) were added. After 3 hours the mixture was diluted with ethyl acetate, and washed with 1N HCl, aqueous sodium bicarbonate and brine. The organic phase was dried (MgSO4), filtered and evaporated. Chromatography of the residue over silica gel (ethyl acetate/hexane 1/3) gave 1-[2′-(S)-tbutoxycarbonylamino-)′-[4″-(1′″-tbutoxycarbonyl-1′″-methyl)ethyl]benzene]propanoylamino-5-bromo-1-(4-methoxybenzyl)-4-methyl-2-pyridone (2.48 g, 3.49 mmol, 44%).

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