Methyl 4-amino-2-chloropyrimidine-5-carboxylate

In the title compound, C6H6ClN3O2, all non-H atoms are approximately coplanar [maximum deviation = 0.012 (4) Å]; an intramolecular N—H⋯O hydrogen bond occurs between the amino group and the carbonyl group. In the crystal, molecules are linked by N—H⋯N hydrogen bonds into supramolecular chains propagated along [101].

In the title compound, C 6 H 6 ClN 3 O 2 , all non-H atoms are approximately coplanar [maximum deviation = 0.012 (4) Å ]; an intramolecular N-HÁ Á ÁO hydrogen bond occurs between the amino group and the carbonyl group. In the crystal, molecules are linked by N-HÁ Á ÁN hydrogen bonds into supramolecular chains propagated along [101].
Diffraction data were collected at the Center of Testing and Analysis, Nanjing University, China.
Supporting information for this paper is available from the IUCr electronic archives (Reference: XU5799).
The molecular structure of (I) is shown in Fig. 1. The bond lengths and angles are within normal ranges (He & Kang, 2006;He et al., 2007). The pyrimidine ring is almost planar.
In the crystal, molecules are linked each other to form chains framework via intermolecular N-H···N hydrogen bonds, which with intramolecular N-H···O hydrogen bonds may be effective in the stabilization of the crystal structure.

S2. Experimental
The title compound was synthesized according to the reported procedure (Ballard & Johnson, 1942). Crystals suitable for X-ray analysis were obtained by dissolving it (0.5 g) in dichloromethane (50 ml) and evaporating the solvent slowly at room temperature for about 5 d.

S3. Refinement
H atoms were positioned geometrically with N-H = 0.86 and C-H = 0.93-0.96 Å, and refined in riding mode, U iso (H) = 1.5U eq (C) for methyl H atoms and 1.2U eq (C,N) for the others.

Figure 1
The molecular structure of (I), with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.  A packing diagram of (I).

Methyl 4-amino-2-chloropyrimidine-5-carboxylate
Crystal data Absolute structure: Flack (1983), 106 Friedel pairs Absolute structure parameter: 0.07 (17) Special details Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes. Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq Cl 1.0210 (5