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Example 1c: Procedure for the synthesis of 1-toluenesulfonyl-1H-pyrrolo[2,3-b]pyridin-3-ylboronic acid (8a): 1. Add THF (28.5 kg) and 3-bromo-1-toluenesulfonyl-1H-pyrrolo[2,3-b]pyridine (7a) (4 kg) in a 72 L reaction flask and stir until the solid is completely dissolved. 2. triisopropyl borate (3.2 kg) was added and the reaction mixture was cooled to below -80 °C. The reaction mixture was then cooled to below -80 °C. 3. n-BuLi (4.65 kg) was added dropwise at a rate of 0.6-0.9 kg/hr at -80 to -90 °C. The reaction mixture was cooled to below -80 °C and the temperature was maintained at -80 °C. 4. After addition, maintain the temperature at -80 to -90 °C and monitor the progress of the reaction by HPLC (Method A). Samples were taken and analyzed after 30 min, and the reaction was judged to be complete when the peak area of 3-bromo-1-toluenesulfonyl-1H-pyrrolo[2,3-b]pyridine (7a) was less than 4%. 5. Quench the reaction by slowly adding water (2 kg) to bring the temperature of the mixture back up to 15-25 °C. 6. Transfer the mixture to a 50 L reactor and concentrate below 40 °C at a pressure below -0.08 MPa until no THF is distilled. 7. The residue was dissolved in water (25 kg) and 10% NaOH aqueous solution (26 kg) with stirring until the solids were completely dissolved. 8. The mixture was filtered through a vacuum filter and the filtrate was extracted twice with MTBE (21 kg each) at 20-30°C, stirring for 15 minutes in each extraction and then allowed to stand for 15 minutes. 9. The aqueous phase was adjusted to pH 3-4 with 28L of HCl, keeping the temperature at 10-20°C. The mixture was then extracted with MTBE (21kg each) twice at 20-30°C. 10. The mixture was stirred at 10-15°C for 1 hour and subsequently transferred to a centrifuge for filtration. 11. The filter cake was washed sequentially with water (5 kg) and petroleum ether (5 kg). 12. The filter cake was dried at 35-45°C until the LOD (loss on drying) was less than 3% to give 2.5 kg of an off-white solid (HPLC purity 98.8%, Method A) in 69.4% yield.

[1] Patent: WO2013/6634, 2013, A2. Location in patent: Paragraph 0387-0389
[2] Patent: WO2013/70606, 2013, A1. Location in patent: Paragraph 00390-00392
[3] Patent: WO2014/74471, 2014, A1. Location in patent: Paragraph 0275-0277