Sodium hydride → HCID 13240319, compound

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Reaction Steps

0.51 g (12 mmole) of 55% sodium hydride in mineral oil was suspended in 10 ml of N,N-dimethylformamide, to which was added gradually 2.40 g (15 mmole) of 3-phenyl-5-pyrazolone with stirring at room temperature. After evolution of hydrogen had ceased, to this solution was added dropwise 20 ml of a solution of 6.10 g (10 mmole) of the 1,4-dihydro-2,6-dimethyl-4-(2,3-dichlorophenyl)-3-methoxycarbonylpyridine-5-carboxylic acid 6-tosyloxyhexyl ester obtained in the above Step i in N,N-dimethylformamide, and stirring with heating at 60° C. was continued for 4 hours. The resultant reaction mixture was poured into 150 ml of ice water, and the separated product was extracted with 50 ml of ethyl acetate. This ethyl acetate solution was washed with 50 ml of water three times, dried over anhydrous sodium sulfate, and then concentrated under reduced pressure to obtain a brown oily residue. This residue was chromatographed on a silica gel column using a chloroform-methanol mixed solution as an eluent, and the eluate fractions containing the intended compound were concentrated under reduced pressure to obtain crystals. These crystals were recrystallized from a mixed solution of benzene-hexane to obtain 2.63 g (yield 43.9%) of the 1,4-dihydro-2,6-dimethyl-4-(2,3-dichlorophenyl)-3-methoxycarbonylpyridine-5-carboxylic acid 6-(5-phenyl-3-pyrazolyloxy)hexyl ester.

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