Synthesis
General procedure for the synthesis of 5-cyanopyrimidine from pyrimidine-5-carboxamide: To a suspension of anhydrous dichloromethane (15 mL) containing pyrimidine-5-carboxamide (262 mg, 2.12 mmol) and triethylamine (481 mg, 4.24 mmol) was added slowly and dropwise a solution of trifluoroacetic anhydride (0.36 mL, dissolved in 4 mL of dichloromethane) at 0 °C. The reaction mixture was stirred at 0°C to room temperature for 2 hours. After completion of the reaction, it was quenched with water (2 mL) and the organic layer was washed sequentially with 1N NaOH solution (5 mL) and brine (2 x 5 mL). The organic phase was dried with anhydrous magnesium sulfate and subsequently concentrated under reduced pressure at less than 30 °C to afford the light yellow solid product 5-cyanopyrimidine (174 mg, 78% yield). The product was characterized by 1H NMR (400 MHz, DMSO): δ 9.44 (s, 1H), 9.31 (s, 2H).
References
[1] Patent: WO2012/129564, 2012, A2. Location in patent: Page/Page column 79
[2] Journal of Medicinal Chemistry, 2013, vol. 56, # 10, p. 3783 - 3805
[3] Journal of Organic Chemistry, 2015, vol. 80, # 5, p. 2676 - 2699
[4] Patent: WO2009/148452, 2009, A1. Location in patent: Page/Page column 71
