Patent ID: 9199964
Filing Date: 2015-12-01
Classification: C07D

Abstract:
1. A process for preparing 3-(3-chloro-1H-pyrazol-1-yl)pyridine (5b), which comprises a) treating 3-hydrazinopyridine.dihydrochloride  with about 1 to about 2 equivalents of acrylonitrile in a (C b) treating the 1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazol-3-amine (9a) with about a 2-fold to about a 10-fold excess of an oxidant in an organic solvent at a temperature of about 25° C. to about 100° C. to provide 3-(3-amino-1H-pyrazol-1-yl)pyridine (8a) c) treating the 3-(3-amino-1H-pyrazol-1-yl)pyridine (8a) with an excess of aqueous hydrochloric acid and about a 1.3-fold to about a 2-fold excess of sodium nitrite at a temperature of about 0° C. to about 25° C. to provide the diazonium salt (8b)  and d) treating the diazonium salt (8b) with about 5 mole percent to about 60 mole percent of copper chloride at a temperature of about 0° C. to about 25° C.