6‐Meth­yl‐2‐pyridone: an elusive structure finally solved

The title compound, C 6 H 7 NO, crystallizes unsolvated from dry toluene after storage for several months at approximately 263 K. Synchrotron radiation was needed in order to carry out data collection because of the small size of the crystals obtained. There are four crystallographically independent mol­ecules in the asymmetric unit. Packing diagrams show that the mol­ecules are linked into infinite chains by hydrogen bonding; two of the four independent mol­ecules link together to form a chain, while the other two mol­ecules form chains involving only their own symmetry equivalents, giving a total of three crystallographically distinct chains in all. The chains are held together by weak π–π inter­actions. This structure provides conclusive proof that, in the absence of any other co‐­crystallized mol­ecule or solvent, the compound exists in the solid state as the pyridone and not the pyridinol tautomer.