2,4-Dioxo-1-(prop-2-yn-yl)-1,2,3,4-tetra-hydro-pyrimidine-5-carbaldehyde.

In the crystal structure of the title compound, C(8)H(6)N(2)O(3), the mol-ecules are linked by a pairs of inter-molecular N-H⋯O hydrogen bonds, forming inversion dimers. The aldehyde group is in the same plane as the pyrimidine ring [with a maximum deviation of 0.083 (2) Å for the O atom), and the linear propargyl group [C-C-C = 178.99 (19)°] makes a dihedral angle of 74.36 (13)° with the ring.