Crystal and molecular structure of 5‐diazo‐2,2‐dimethyl‐4,6‐dioxo‐1,3‐dioxane and 5‐diazo‐1,3‐dimethylpyrimidin‐2,4,6‐trione

C 6 N 2 O 4 H 6 : M r = 170.12, orthorhombic space group Pbca, a = 6.751(2), b = 13.669(4), c = = 16.845(4) Å, V = 1555(1) Å 3 , D x = 1.248 Mgm −3 , Z = 8, F (000) = 704, λ(moKα) = 0.71069 Å, μ = 1.1 mm −1 . The crystal structure was determined by direct methods and refined by least‐squares procedure to the discrepancy factor R = 0.039. C 6 N 4 O 3 H 6 : M r = 182.14, monoclinic space group C2/c, a = 17.726(8), b = 6.191(12), c = 16.062(6) Å, β = 117.59 (3)°, V = 1562 (1) Å 3 , D x = 1.549 Mgm −3 , Z = 8, F (000) = 752, λ(MoKα) = 0.71069 Å, μ = 1.2 mm −1 . The crystal structure was determined by direct methods and refined by least‐squares procedure to the discrepancy factor R = 0.056.