Oxalyl chloride → 5-[2-(4-bromo-2-chloro-phenyl)-acetyl]-1-methyl-1H-pyridin-2-one

Beteiligte Stoffe

Reaktionsschritte

To a suspension of 1-methyl-6-oxo-1,6-dihydro-pyridine-3-carboxylic acid (606 mg) in CH2Cl2 (5 ml) were added one drop of N,N-dimethylformamide and oxalylchloride (803 mg). The mixture was stirred at room temperature for 1.5 h and was then concentrated to dryness. 1,2-Dimethoxyethane was added and the solvent was evaporated again to give the crude acid chloride. To a suspension of zinc powder (517 mg) in 1,2-dimethoxyethane (5 ml) was added tetrakis(triphenylphosphine)palladium(0) (55 mg). A suspension of the acid chloride in 1,2-dimethoxyethane (5 ml) was added. The mixture was cooled in an ice bath and a solution of 4-bromo-1-bromomethyl-2-chloro-benzene (1.125 g) in 1,2-dimethoxyethane (5 ml) was slowly added over 30 min. The mixture was stirred for 30 min at 0° C. and for 1.5 h at room temperature. The mixture was filtered and the filtrate was concentrated. The product was purified by chromatography (SiO2, cyclohexane/EtOAc 7:3=>0:1) to give the title compound (603 mg, not completely pure) as a colorless solid. MS (m/e, ISP neg. ion)=338.0 [M−H+].

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