33252-30-1

White to off-white solid

2-Chloro-4-cyanopyridine is an intermediate used to prepare pyrrolopyridine inhibitors of mitogen-activated protein kinase-activated protein kinase 2 (MK-2). It is also used to synthesize pyridinyl-tetrazoles as scaffold to identify matrix MMP-13 inhibitors for treatment of osteoarthritis.

The general procedure for the synthesis of 2-chloro-4-cyanopyridine from 4-cyanopyridine N-oxide was as follows: 120 g of 4-cyanopyridine-N-oxide, 360 mL of 1,2-dichloroethane, and 183.6 g of phosphorochloridic acid were added sequentially in a 1000 mL three-necked reaction flask. After the reaction system was cooled to -2±2°C, 151.5 g of triethylamine was added slowly dropwise for a controlled dropwise time of 2 hours. After the dropwise addition, the reaction was continued at the same temperature with stirring for 2 hours. Upon completion of the reaction, the reaction solution was concentrated by reduced pressure distillation until no fractions flowed out. 240 mL of water was added to the concentrated solution and a large amount of solid was precipitated after thorough stirring. The solid was collected by filtration and the filter cake was washed with appropriate amount of water to obtain 117.5 g of white solid product 2-chloro-4-cyanopyridine.

[1] Tetrahedron Letters, 2001, vol. 42, # 39, p. 6815 - 6818
[2] Patent: CN104945383, 2017, B. Location in patent: Paragraph 0031; 0035; 0036