2-Diethyl-amino-6-methyl-pyrimidin-4(3H)-one.

The title compound, C9H15N3O, contains four mol­ecules (A, B, C and D) in the asymmetric unit. In the crystal, the A+A and D+D pairs form inversion dimers linked by pairs of N—H⋯O hydrogen bonds. The B+C pairing is linked by the same bonds. The dimers are further linked by weak C—H⋯O inter­actions.