Patent ID: 9249122
Filing Date: 2016-02-02
CPC Classification: C07D

Claim Text:
1. A process for preparing 3-(3-chloro-1H-pyrazol-1-yl)pyridine (5b), which comprises a) treating 3-hydrazinopyridine•dihydrochloride with acrylonitrile in a (C 1 -C 4 ) aliphatic alcohol at a temperature of about 25° C. to about 100° C. in the presence of an alkali metal (C 1 -C 4 ) alkoxide to provide 1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazol-3-amine (9a) b) treating the 1-(pyridin-3-yl)-4,5-dihydro-1H-pyrazol-3-amine (9a) with 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) in aqueous hydrochloric acid with 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 copper chloride at a temperature of about 0° C. to about 25° C.