Yield:943323-65-7 52.5%

Reaction Conditions:

with tin(II) chloride dihdyrate;hydrogen bromide in water at 70; for 1 h;

Steps:

3.2 Step 2: Preparation of 4-Bromo-1 H-pyrrolo[2,3-b]pyridin-3-ylamine

4-Bromo-3-nitro-1H-pyrrolo[2,3-b]pyridine (500mg, 2.07mmol) was heated in 48% aqueous hydrobromic acid (4mL) at 70°C and then tin (II) chloride dihydrate(2.26g, 10mmol) was added in portions. After addition the reaction was heated at 70°C for a further 1 hour and then cooled before carefully adding to stirring ice/H20 (l5mL). This solution was basified to pH 12 using sodium hydroxidesolution, and the insoluble material separated via filtration. The filtrate wasextracted with DCM (3xlOOmL) and the combined extracts were washed with H2O and saturated aqueous sodium chloride, dried (Mg504) and concentrated in vacuo. This afforded the desired compound, 230mg, 52.5%, which was used without further purification.

References:

WO2013/114113,2013,A1 Location in patent:Page/Page column 26