Table 1: The crystal data, structure solution, and refinement parameters for (I).

Empirical formula C13H14N4O6 Formula weight 322.28 Temperature 294 (2) K Crystal system, space group Monoclinic, P21 Unit cell dimensions a = 5.147 (3) Å; b = 7.228 (5) Å c = 18.887 (1) Å; β = 92.72 (1)° Volume 701.8 (8) Å3 Z, calculated density 2, 1.525 kg/m3 Absorption coefficient 0.123 mm−1 F(000) 336 Crystal size 0.24 × 0.25 × 0.26 mm3 Theta range 2.16° to 24.99° Limiting indices Reflections collected/unique 6680/1347 (int) = 0.0176 Completeness to θ = 25° 99.9% Data/restraints/parameters 1347/6/228 Goodness-of-fit on F 2 1.068 Final R indices I > 2σ (I) , R indices (all data) , Largest diff. peak and hole 0.166 and −0.141 e·Å−3