873551-20-3

To a solution of tert-butyl 4-(((trifluoromethyl)sulfonyl)oxy)-5,6-dihydropyridine-1(2H)-carboxylate (6.0 g, 18 mmol) in dimethyl sulfoxide (60 mL) was added tetrakis(triphenylphosphine)palladium(0) (0.84 g, 0.73 mmol) and zinc cyanide (3.81 g, 32 mmol). The reaction mixture was heated to 100 °C and stirred for 2 hours. After completion of the reaction, the reaction mixture was diluted with water and extracted with ethyl acetate. The organic layers were combined, washed sequentially with water and saturated saline, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue was purified by fast column chromatography (eluent: 5% ethyl acetate/hexane) to afford tert-butyl 4-cyano-5,6-dihydropyridine-1(2H)-carboxylate (3.5 g). Mass spectrum (MS): m/z = 209 (M + 1).

[1] Patent: WO2013/127808, 2013, A1. Location in patent: Page/Page column 31
[2] Patent: US2015/31541, 2015, A1. Location in patent: Paragraph 0146