Yield:943323-63-5 84%

Reaction Conditions:

with nitric acid in sulfuric acid at 0; for 1 h;

Steps:

89.a

To a solution of 4-bromo-1 H-pyrrolo[2,3-b]pyridine (1 1 g, 55.8 mmol)[prepared according to Preparation 2] in H₂SO₄ (50 ml_) cooled to 0 °C was added a pre-cooled solution of HNO₃ (5.1 mL) in H₂SO₄ (3.5 mi_). After 1 h, the solution was poured over ice and the precipitate was filtered and dried affording the title compound (11.4 g, 84%) as a yellow solid: LC-MS (ES) m/z 243 (M+H)⁺.

References:

WO2007/76423,2007,A2 Location in patent:Page/Page column 154