Synthesis
General procedure for the synthesis of cyclopentanone-2-carbonitrile from hexanedinitrile:
Synthesis of intermediate 1: 2-oxocyclopentanonecarbonitrile
Potassium tert-butanolate (41.51 g, 370 mmol) was added to a stirred mixed solution of hexanedinitrile (426 mL, 370 mmol) and THF (600 mL) at room temperature and under nitrogen protection. The reaction mixture was stirred for 8 h. After stirring for 8 h, a 1 M solution of H2F4 (19.72 mL, 370 mmol) was added and stirring was continued for 18 h at room temperature. After completion of the reaction, aqueous NH4Cl solution (600 mL) was added and extracted with EtOAc (2 x 500 mL). The organic layers were combined, dried over Na2SO4 and concentrated under reduced pressure to remove the solvent to give 2-oxocyclopentanecarbonitrile as a yellow oil (29.31 g, 269 mmol, 73% yield).
1H NMR (CDCl3, 400 MHz) δ/ppm: 3.20 (1H, dd, J = 8.4 Hz, 10.2 Hz), 2.15-2.60 (5H, m), 1.92 (1H, m).
MS (Method 2): RT: 0.76 min, m/z 110.1 [M + H]+.
References
[1] Journal of Organic Chemistry, 2007, vol. 72, # 4, p. 1431 - 1436
[2] Tetrahedron Letters, 1984, vol. 25, # 7, p. 753 - 756
[3] Patent: WO2016/51193, 2016, A1. Location in patent: Paragraph 00187
[4] Angewandte Chemie - International Edition, 2014, vol. 53, # 16, p. 4177 - 4180
[5] Angew. Chem., 2014, vol. 126, # 16, p. 4261 - 4264,4