<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The title compound is prepared by reaction of Co(O‐Ac)<sub>2</sub> and 85% H<sub>3</sub>PO<sub>4</sub> in the ionic liquid 1‐butyl‐4‐methyl‐pyridinium hexafluorophosphate (autoclave, 200 °C, 7 d).</p> </abstract>