Patent ID: 8293918

Claim:
A process for preparing a 2,3-dihalopyridine of formula (I): the process comprising: (a) halogenating a 3-aminopyridine of formula (II) or a salt thereof with a halogenating agent in the presence of ferric chloride to obtain a crude 3-amino-2-halopyridine of formula (III): (b) diazotizing the crude 3-amino-2-halopyridine of formula (III) with a nitrite salt to obtain a diazonium salt; (c) reacting the diazonium salt with a halo acid in presence of a copper (I) catalyst to form a crude mass of the 2,3-dihalopyridine of formula (I); (d) separating undesired products from the crude mass by combining the crude mass with a water immiscible organic solvent and extracting an organic phase comprising the undesired products to yield a resultant aqueous mass; and (e) diluting the resultant aqueous mass with water, followed by extraction with the same or another water immiscible organic solvent to obtain the 2,3-dihalopyridine of formula (I).