Synthesis and Crystal Structure of 7-Amino-2,3,4,5-tetrahydro-1,3-dimethyl-5-(2-nitrophenyl)-2,4-dioxo-1H-pyrano[2,3-d]pyrimidine-6-carbonitrile DMF Solvate

The title compound 7-amino-2,3,4,5-tetrahydro-1,3-dimethyl-5-(2-nitrophenyl)-2,4-dioxo-1H-pyrano[2,3-d] pyrimidine-6-carbonitrile DMF solvate 1 (C19H20N6O6, Mr=428.41) was synthesized and crystallized. The crystal belongs to the monoclinic system, space group P21/c with a=11.383(2), b=13.372(2), c=13.673(2), β=97.380(4)o, Z=4, V=2063.8(6)3, Dc= 1.379 g/cm3, μ(MoKα)=0.105 mm-1, F(000)=896, the final R=0.0738 and wR=0.1647 for 2964 observed reflections (I > 2σ(I)). X-ray analysis reveals that the new pyran ring is coplanar, which is obviously different from those of other similar compounds. In addition, the unclassical hydrogen bonds of C-H···O and C-H···N are presented in the crystals except for the normal hydrogen bonds of N-H···O.