Ammonium Chloride → Ethyl 6-(2,3-dichlorobenzyl)-1,4-dihydro-8-fluoro-1-[2-(tert-butyldimethylsilyloxy)ethyl]-4-oxo-3-quinolinecarboxylate

関与物質

反応手順

Under an argon stream, the 1M THF solution (2.9 ml, 2.9 mmol) of 2,3-dichlorobenzylzinc chloride obtained in the same manner as in Reference Example 1 was added to THF (20 ml), then bis(dibenzylidenacetone)palladium(0) (22 mg, 0.039 mmol), tri(2-furyl)phosphine (18 mg, 0.077 mmol) and ethyl 1,4-dihydro-8-fluoro-6-iodo-1-[2-(tert-butyldimethylsilyloxy)ethyl]-4-oxo-3-quinolinecarboxylate (1.0 g, 1.9 mmol) obtained in Step 4 were added. The mixture was stirred at room temperature for 17 hr, a solution (1.0 ml, 1.0 mmol) of 2,3-dichlorobenzylzinc chloride in THF was further added, and the mixture was heated under reflux for 1 hr. After allowing to cool, saturated aqueous ammonium chloride solution was added to the reaction mixture, and the insoluble material was filtered through celite. The filtrate was extracted with ethyl acetate. The organic layer was washed with water and saturated brine, and dried over sodium sulfate. After filtration, the filtrate was concentrated under reduced pressure, and the obtained residue was crudely purified by silica gel chromatography (ethyl acetate:hexane=1:1) and successively purified by PTLC (ethyl acetate:chloroform=1:2) to give the object product (562 mg, yield 53%) as a pale-yellow oil.

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