N-Iodosuccinimide → 6-Bromo-3-iodo-8-(methylthio)imidazo[1,2-a]pyrazine

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 6-bromo-8-methylsulfanyl-imidazo[1,2-a]pyrazine (210.0 g, 860.3 mmol) in DMF (4200 mL) was added NIS (212.9 g, 946.3 mmol, 1.1 eq) in one portion at rt. After 18 h stirring at 60° C. the dark solution was evaporated and the brown residue was dissolved in DCM (7 L), washed with water (2×5 L) and sole (2×5 L) and dried over sodium sulphate. Crystallization by careful removal of solvent yielded 255 g (80.1%) 6-bromo-3-iodo-8-methylsulfanyl-imidazo[1,2-a]pyrazine: 1H-NMR (300 MHz, d6-DMSO): δ=8.24 (1H, s), 7.79 (1H, s), 2.46 (3H, s) ppm.

Provenance & Evidence