1040682-68-5

Step 1: Under nitrogen protection, 4-chloro-1H-pyrrolo[3,2-c]pyridine (500 mg, 3.28 mmol), zinc cyanide (422 mg, 3.61 mmol), tris(dibenzylideneacetone)dipalladium (Pd2(dba)3, 600 mg, 0.656 mmol), 1,1'-bis(diphenylphosphino)ferrocene (dppf. 729 mg, 1.312 mmol) and zinc powder (21 mg, 0.328 mmol) were dissolved in N-methylpyrrolidone (NMP, 30 mL). The reaction mixture was stirred at 120 °C for 18 hours. After completion of the reaction, it was cooled to room temperature and the mixture was poured into water (150 mL) and extracted with dichloromethane (DCM, 3 x 50 mL). The organic layers were combined, dried with anhydrous magnesium sulfate (MgSO4), filtered and concentrated under reduced pressure. The crude product was purified by silica gel (SiO2) column chromatography with petroleum ether/ethyl acetate (1:1, v/v) as eluent to afford 1H-pyrrolo[3,2-c]pyridine-4-carbonitrile as a white solid (150 mg, 32% yield). Mass spectrum (ESI) m/z: 144.3 [M + H]+.

[1] Patent: WO2013/92940, 2013, A1. Location in patent: Page/Page column 38; 39
[2] Patent: WO2018/11628, 2018, A1. Location in patent: Paragraph 00682