Potassium Cyanide → 2-(6-Bromopyridin-3-yl)acetonitrile
Reaktionsgleichung
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8]Br)=[CH:4][N:3]=1.[C-:10]#[N:11].[K+]>CN(C)C=O>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([CH2:8][C:10]#[N:11])=[CH:4][N:3]=1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
The 476 g of crude 2-bromo-5-bromomethylpyridine from step 4 was dissolved in 4000 mL of dimethylformamide (DMF)/water (7:1) and treated with 168 g (2.58 mol) of potassium cyanide. The reaction was allowed to stir at ambient temperature for 72 h, concentrated in vacuo, and partitioned between ethyl acetate and water; the organic layer was washed with water, washed with brine, dried (MgSO4), and reconcentrated in vacuo to provide the crude nitrile. Purification by silica gel chromatography (Waters Prep-500A) using ethyl acetate/hexane (25:75) gave 109 g (32% from 2-bromo-5-picoline) of 2-bromo-5-cyanomethylpyridine as a yellowish orange solid: mp 55.5°-57.5° C.; NMR (CDCl3)δ3.74 (s, 2 H), 7.54 (d, J=8 Hz, 1 H), 7.59 (dd, J=8 and 2 HZ, 1 H), 8.35 (d, J=2 Hz, 1 H); MS (FAB) m/e (rel intensity) 199 (85), 197 (100).