Crystal structure of the α-racemate of methohexital

Mol­ecules of the title compound, C(14)H(18)N(2)O(3) [systematic name: 5-allyl-5-(hex-3-yn-2-yl)-1-methylpyrimidine-2,4,6(1H,3H,5H)-trione in the (R(b)S(h))/(S(b)R(h)) racemic form], are connected by mutual N—H⋯O=C hydrogen bonds in which the carbonyl group at the 2-position of the pyrimidine­trione ring is employed. These inter­actions result in an inversion dimer which displays a central R (2) (2)(8) ring motif. This dimer is topologically distinct from that of the previously reported (S(b)R(h)) form, which is, however, also based on an R (2) (2)(8) motif. The methyl group at the 1-position of the pyrimidine­trione ring in the title structure is disordered over two sets of sites in a 0.57 (2):0.43 (2) ratio.