Patent ID: 9255081
Filing Date: 2016-02-09
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 between about a 1.5-fold to about a 2-fold excess of an alkoxyacrylonitrile 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 3-(3-amino-1H-pyrazol-1-yl)pyridine (8a) b) treating the 3-(3-amino-1H-pyrazol-1-yl)pyridine (8a) in aqueous hydrochloric acid with sodium nitrite in an excess of about 1.3-fold to about 2-fold at a temperature of about 0° C. to about 25° C. to provide the diazonium salt (8b) and c) treating the diazonium salt (8b) with from about 5 mole percent to about 60 mole percent excess of a copper chloride a temperature of about 0° C. to about 25° C.