反应详情

温度

0 °C

Add dropwise a solution of (6-bromo-pyridin-2-yl)-dimethyl-amine (8; g, 39.8 mmol) in anhydrous tetrahydrofuran (10; mL) to a stirring cooled solution of n-butyl-lithium in hexanes (2.5; M, 19.1; mL, 47.7; mmol) in anhydrous tetrahydrofuran (160; mL) under nitrogen at −75° C. at a rate so that the internal reaction temperature does not exceed −70° C. After 1; h at −75° C., add dropwise tri-n-butyltin chloride (13; g, 39.8; mmol), stir for 30; min and warm to 0° C. Add water (200; mL) and then dilute with a saturated aqueous solution of sodium bicarbonate (50; mL) and diethyl ether (200; mL) and separate the layers. Extract the organic phase once with brine (200; mL), dry over sodium sulfate, filter and concentrate to give a liquid (25.4; g). Purify by silica gel chromatography eluting with iso-hexane:ethyl acetate:triethylamine 90:9:1, to give the title product as a colorless liquid (8.16; g, 50%). MS (m/z): 409-414; cluster (M+1).

1. customdoes not exceed −70° C
2. customseparate the layers
3. extractionExtract the organic phase once with brine (200; mL)
4. dry with materialdry over sodium sulfate
5. filtrationfilter
6. concentrationconcentrate
7. customto give a liquid (25.4; g)
8. customPurify by silica gel chromatography
9. washeluting with iso-hexane:ethyl acetate:triethylamine 90:9:1