5-bromo-6-chloronicotinonitrile synthesis

Yield:71702-01-7 55%

Reaction Conditions:

with tert.-butylnitrite;copper dichloride in acetonitrile at 65; for 3 h;

Steps:

36.2

Step 2; 5-Bromo-6-chloro-nicotinonitrile; To a solution of anhydrous CuCl2 (77 mg, 0.58 mmol) in CH3CN (3 mL) add tert- BuONO (0.72 mmol). Heat the mixture at 65°C and then add a suspension of the intermediate above (96 mg, 0.48 mmol) in CH3CN (2 mL). Stir the mixture for 3 hours. Cool at room temperature. Pour into HCI 3M and extract with EtOAc. Dry the organic layer over Na2SO4. Eliminate the solvent. Purify by flash chromatography on silica gel (eluent: hexane/EtOAc 2/1) to afford the title compound (55 mg, 55%). 'H-NMR (DMSO, 300 MHz): 8.93 (s, 1H), 8.90 (s, 1H).

References:

WO2005/90337,2005,A1 Location in patent:Page/Page column 43