Bromide ion → 1-(5'-chloro-3,4,5,6-tetrahydro-2H-[1,2']bipyridinyl-4-yl)-pent-4-en-1-one

関与物質

反応条件

反応手順

While under a nitrogen atmosphere, a solution of 5′-chloro-3,4,5,6-tetrahydro-2H-[1,2′]bipyridinyl-4-carboxylic acid, methoxy-methyl-amide (1.0 g, 3.5 mmol), in tetrahydrofuran (10 mL) was cooled to 0° C. and treated with 4-butenylmagnesiun bromide (0.5 M in THF, 17.6 mL, 8.8 mmol) dropwise. After stirring for 1 hour at 0° C. and room temperature overnight the reaction mixture was poured into water, acidified to pH 3-4 with 1N hydrochloric acid and extracted with ethyl acetate (3×). The combined organic phase was washed with saturated aqueous sodium chloride, dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. Purification by flash column chromatography (silica gel, 0-25% ethyl acetate in heptane) gave 1-(5′-chloro-3,4,5,6-tetrahydro-2H-[1,2′]bipyridinyl-4-yl)-pent-4-en-1-one as a colorless oil (904 mg, 93%); 1H NMR (CDCl3, 300 MHz) δ 8.05 (d, J=2.5 Hz, 1H), 7.42 (dd, J1=9.0 Hz, J2=2.5 Hz, 1H), 6.62 (d, J=9.0 Hz, 1H), 5.80 (m, 1H), 5.04 (m, 2H), 4.23 (m, 2H), 2.92 (m, 2H), 2.59 (m, 3H), 2.36 (m, 2H), 1.98 (m, 2H) and 1.70 (m, 2H); MS (+CI): m/z for C15H19ClN2O: expected 278.1. found 279.2 (M+H)+.

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