Related literature   {#sec1}
====================

For related structures, see: Jain *et al.* (2004[@bb5]); Lin *et al.* (2001[@bb6]); Roodt *et al.* (2011[@bb7]); Schutte *et al.* (2011[@bb8]); Van der Berg *et al.* (2011[@bb10]).

Experimental   {#sec2}
==============

 {#sec2.1}

### Crystal data   {#sec2.1.1}

C~20~H~18~N~4~O~2~*M* *~r~* = 346.38Monoclinic,*a* = 12.1299 (8) Å*b* = 18.9418 (8) Å*c* = 7.7549 (4) Åβ = 100.375 (4)°*V* = 1752.65 (17) Å^3^*Z* = 4Mo *K*α radiationμ = 0.09 mm^−1^*T* = 100 K0.78 × 0.08 × 0.07 mm

### Data collection   {#sec2.1.2}

Bruker X8 APEXII KappaCCD diffractometerAbsorption correction: multi-scan (*SADABS*; Bruker, 2004[@bb2]) *T* ~min~ = 0.990, *T* ~max~ = 0.99415674 measured reflections3860 independent reflections3529 reflections with *I* \> 2σ(*I*)*R* ~int~ = 0.031

### Refinement   {#sec2.1.3}

*R*\[*F* ^2^ \> 2σ(*F* ^2^)\] = 0.036*wR*(*F* ^2^) = 0.090*S* = 1.043860 reflections237 parameters2 restraintsH atoms treated by a mixture of independent and constrained refinementΔρ~max~ = 0.26 e Å^−3^Δρ~min~ = −0.20 e Å^−3^

 {#d5e467}

Data collection: *APEX2* (Bruker, 2010[@bb3]); cell refinement: *SAINT-Plus* (Bruker, 2004[@bb2]); data reduction: *SAINT-Plus*; program(s) used to solve structure: *SHELXS97* (Sheldrick, 2008[@bb9]); program(s) used to refine structure: *SHELXL97* (Sheldrick, 2008[@bb9]); molecular graphics: *DIAMOND* (Brandenburg & Putz, 2005[@bb1]); software used to prepare material for publication: *WinGX* (Farrugia, 1999[@bb4]).

Supplementary Material
======================

Crystal structure: contains datablock(s) global, I. DOI: [10.1107/S1600536812035064/zs2225sup1.cif](http://dx.doi.org/10.1107/S1600536812035064/zs2225sup1.cif)

Structure factors: contains datablock(s) I. DOI: [10.1107/S1600536812035064/zs2225Isup2.hkl](http://dx.doi.org/10.1107/S1600536812035064/zs2225Isup2.hkl)

Additional supplementary materials: [crystallographic information](http://scripts.iucr.org/cgi-bin/sendsupfiles?zs2225&file=zs2225sup0.html&mime=text/html); [3D view](http://scripts.iucr.org/cgi-bin/sendcif?zs2225sup1&Qmime=cif); [checkCIF report](http://scripts.iucr.org/cgi-bin/paper?zs2225&checkcif=yes)

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: [ZS2225](http://scripts.iucr.org/cgi-bin/sendsup?zs2225)).

The authors would like to thank the Department of Chemistry of the University of the Free State, the NRF, NTeMBI, THRIP and Sasol Ltd for funding.

Comment
=======

The title compound C~20~H~18~N~4~O~2~ was synthesized as a ligand for potential use in medical and radiopharmaceutical applications. In this compound, which has one molecule in the asymmetric unit (Fig. 1), the dihedral angles between the central benzene ring and the pyridine rings are 57.55 (6) and 22.05 (8)°. The molecular conformation is stabilized by intramolecular N---H···N interactions and in the crystal structure an intermolecular asymmetric cyclic hydrogen-bonding association involving both amide N---H donors and a common amide O-atom acceptor (O2^i^) (Table 1), give a one-dimensional chain extending along *c*. The related structures from Roodt *et al.* (2011) and Schutte *et al.* (2011) also contribute to our studies in radiopharmaceutical design and reactivity.

Experimental {#experimental}
============

Under oxygen atmosphere, picolinic acid (5.73 g, 0.0465 mol) was added as a solid in one portion to a suspension of 4,5-dimethyl-1,2-phenylenediamine (3.00 g, 0.0220 mol) in pyridine (20 ml) and the mixture was stirred at 40 °C for 40 min. Triphenylphosphite (30 ml) was added dropwise over 10 minutes after which the temperature was increased to 90--100 °C and stirred for a further 24 h. On cooling the precipitate was filtered, washed with H~2~O (50 ml) and then MeOH (50 ml). The precipitate was recrystallized in chloroform to giving colourless crystals after five days

Refinement {#refinement}
==========

The amides, aromatic and methyl hydrogen atoms were positioned geometrically and allowed to ride on their parent atoms, N---H = 0.86 Å and *U*~iso~(H) = 1.2*U*~eq~, C---H (aromatic C) = 0.95 Å and *U*~iso~(H) = 1.2*U*~eq~ and C---H (methyl C) = 0.98 Å and *U*~iso~(H) = 1.5*U*~eq~ respectively. The methyl groups were allowed to rotate, giving six half-H sites.

Figures
=======

![Molecular structure of the title compound, showing the atom numbering scheme, with displacement ellipsoids drawn at the 50% probability level.](e-68-o2739-fig1){#Fap1}

Crystal data {#tablewrapcrystaldatalong}
============

  ------------------------- ---------------------------------------
  C~20~H~18~N~4~O~2~        *F*(000) = 728
  *M~r~* = 346.38           *D*~x~ = 1.313 Mg m^−3^
  Monoclinic, *Cc*          Mo *K*α radiation, λ = 0.71073 Å
  Hall symbol: C -2yc       Cell parameters from 5487 reflections
  *a* = 12.1299 (8) Å       θ = 3.1--28.3°
  *b* = 18.9418 (8) Å       µ = 0.09 mm^−1^
  *c* = 7.7549 (4) Å        *T* = 100 K
  β = 100.375 (4)°          Needle, colourless
  *V* = 1752.65 (17) Å^3^   0.78 × 0.08 × 0.07 mm
  *Z* = 4                   
  ------------------------- ---------------------------------------

Data collection {#tablewrapdatacollectionlong}
===============

  ------------------------------------------------------------ --------------------------------------
  Bruker X8 APEXII KappaCCD diffractometer                     3860 independent reflections
  Radiation source: sealed tube                                3529 reflections with *I* \> 2σ(*I*)
  Graphite monochromator                                       *R*~int~ = 0.031
  φ and ω scans                                                θ~max~ = 28°, θ~min~ = 3.1°
  Absorption correction: multi-scan (*SADABS*; Bruker, 2004)   *h* = −16→16
  *T*~min~ = 0.990, *T*~max~ = 0.994                           *k* = −24→24
  15674 measured reflections                                   *l* = −10→10
  ------------------------------------------------------------ --------------------------------------

Refinement {#tablewraprefinementdatalong}
==========

  ------------------------------------- -------------------------------------------------------------------------------------------------
  Refinement on *F*^2^                  Primary atom site location: structure-invariant direct methods
  Least-squares matrix: full            Secondary atom site location: difference Fourier map
  *R*\[*F*^2^ \> 2σ(*F*^2^)\] = 0.036   Hydrogen site location: inferred from neighbouring sites
  *wR*(*F*^2^) = 0.090                  H atoms treated by a mixture of independent and constrained refinement
  *S* = 1.04                            *w* = 1/\[σ^2^(*F*~o~^2^) + (0.0456*P*)^2^ + 0.7043*P*\] where *P* = (*F*~o~^2^ + 2*F*~c~^2^)/3
  3860 reflections                      (Δ/σ)~max~ = 0.001
  237 parameters                        Δρ~max~ = 0.26 e Å^−3^
  2 restraints                          Δρ~min~ = −0.20 e Å^−3^
  ------------------------------------- -------------------------------------------------------------------------------------------------

Special details {#specialdetails}
===============

  ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  Experimental. The intensity data was collected on a Bruker X8 ApexII 4 K Kappa CCD diffractometer using an exposure time of 30 s/frame. A total of 1895 frames was collected with a frame width of 0.5° covering up to θ = 28.29° with 99.9% completeness accomplished.
  Geometry. All s.u.\'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.\'s are taken into account individually in the estimation of s.u.\'s in distances, angles and torsion angles; correlations between s.u.\'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.\'s is used for estimating s.u.\'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^ \> 2σ(*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^) {#tablewrapcoords}
==================================================================================================

  ------ -------------- -------------- -------------- -------------------- ------------
         *x*            *y*            *z*            *U*~iso~\*/*U*~eq~   Occ. (\<1)
  C6     0.77131 (13)   0.70520 (9)    0.3849 (2)     0.0204 (3)           
  C10    0.34827 (15)   0.64314 (11)   0.4195 (3)     0.0336 (4)           
  H10A   0.2857         0.6104         0.4193         0.050\*              0.5
  H10B   0.3246         0.6815         0.3361         0.050\*              0.5
  H10C   0.3713         0.6629         0.5373         0.050\*              0.5
  H10D   0.3688         0.6927         0.4424         0.050\*              0.5
  H10E   0.3298         0.6217         0.5257         0.050\*              0.5
  H10F   0.2831         0.6403         0.3245         0.050\*              0.5
  C11    0.33503 (15)   0.48994 (11)   0.3373 (3)     0.0313 (4)           
  H11A   0.3459         0.4411         0.3025         0.047\*              0.5
  H11B   0.2703         0.5102         0.2592         0.047\*              0.5
  H11C   0.3218         0.4908         0.4583         0.047\*              0.5
  H11D   0.2794         0.5204         0.3775         0.047\*              0.5
  H11E   0.355          0.4512         0.4208         0.047\*              0.5
  H11F   0.3035         0.4706         0.2217         0.047\*              0.5
  C15    0.77150 (13)   0.44582 (8)    0.2917 (2)     0.0202 (2)           
  N2     0.73461 (11)   0.64533 (7)    0.2985 (2)     0.0221 (3)           
  N3     0.72056 (11)   0.50299 (7)    0.21172 (19)   0.0190 (3)           
  O1     0.72183 (10)   0.73844 (7)    0.48200 (17)   0.0277 (3)           
  O2     0.74071 (9)    0.41395 (6)    0.41242 (15)   0.0202 (2)           
  H2\'   0.7803 (17)    0.6283 (10)    0.237 (3)      0.027 (5)\*          
  H3\'   0.7438 (16)    0.5199 (10)    0.122 (3)      0.024 (5)\*          
  C1     1.03548 (14)   0.71236 (10)   0.2222 (2)     0.0283 (4)           
  H1     1.0731         0.6853         0.1474         0.034\*              
  C2     1.08852 (15)   0.77174 (10)   0.3009 (2)     0.0293 (4)           
  H2     1.1603         0.7852         0.2795         0.035\*              
  C3     1.03552 (16)   0.81103 (10)   0.4107 (2)     0.0289 (4)           
  H3     1.07           0.8521         0.4668         0.035\*              
  C4     0.93064 (15)   0.78956 (9)    0.4380 (2)     0.0249 (4)           
  H4     0.8918         0.8154         0.5134         0.03\*               
  C5     0.88403 (13)   0.72965 (9)    0.3529 (2)     0.0197 (3)           
  C7     0.63512 (12)   0.60847 (8)    0.3093 (2)     0.0192 (3)           
  C8     0.54288 (15)   0.64111 (9)    0.3586 (2)     0.0241 (3)           
  H8     0.5468         0.6899         0.3874         0.029\*              
  C9     0.44549 (13)   0.60415 (9)    0.3667 (2)     0.0243 (4)           
  C12    0.43827 (14)   0.53253 (9)    0.3249 (2)     0.0235 (3)           
  C13    0.53017 (14)   0.50011 (9)    0.2728 (2)     0.0215 (3)           
  H13    0.5258         0.4515         0.2421         0.026\*              
  C14    0.62761 (12)   0.53699 (8)    0.2646 (2)     0.0189 (3)           
  C16    0.87530 (13)   0.42368 (9)    0.2250 (2)     0.0189 (3)           
  C17    0.93911 (15)   0.36937 (9)    0.3085 (2)     0.0255 (4)           
  H17    0.9157         0.344          0.4012         0.031\*              
  C18    1.03894 (15)   0.35268 (10)   0.2530 (3)     0.0295 (4)           
  H18    1.0859         0.316          0.3079         0.035\*              
  C19    1.06792 (15)   0.39063 (10)   0.1168 (2)     0.0283 (4)           
  H19    1.1357         0.3806         0.0764         0.034\*              
  C20    0.99767 (15)   0.44332 (10)   0.0395 (3)     0.0301 (4)           
  H20    1.0181         0.4685         −0.056         0.036\*              
  N1     0.93415 (12)   0.69083 (8)    0.2456 (2)     0.0248 (3)           
  N4     0.90251 (12)   0.46069 (8)    0.09200 (19)   0.0245 (3)           
  ------ -------------- -------------- -------------- -------------------- ------------

Atomic displacement parameters (Å^2^) {#tablewrapadps}
=====================================

  ----- ------------- ------------- ------------- ------------- ------------ -------------
        *U*^11^       *U*^22^       *U*^33^       *U*^12^       *U*^13^      *U*^23^
  C6    0.0205 (7)    0.0210 (8)    0.0200 (8)    0.0032 (6)    0.0050 (6)   0.0032 (6)
  C10   0.0211 (8)    0.0387 (10)   0.0437 (12)   0.0041 (7)    0.0132 (8)   −0.0001 (9)
  C11   0.0227 (8)    0.0378 (10)   0.0351 (10)   −0.0060 (7)   0.0102 (8)   −0.0020 (8)
  C15   0.0209 (4)    0.0201 (5)    0.0205 (4)    −0.0022 (3)   0.0064 (4)   −0.0014 (4)
  N2    0.0184 (7)    0.0206 (7)    0.0304 (8)    0.0008 (5)    0.0124 (6)   −0.0027 (6)
  N3    0.0181 (6)    0.0214 (7)    0.0192 (7)    −0.0007 (5)   0.0081 (5)   0.0004 (6)
  O1    0.0252 (6)    0.0322 (7)    0.0283 (7)    0.0007 (5)    0.0117 (5)   −0.0061 (6)
  O2    0.0209 (4)    0.0201 (5)    0.0205 (4)    −0.0022 (3)   0.0064 (4)   −0.0014 (4)
  C1    0.0238 (8)    0.0362 (10)   0.0265 (9)    −0.0018 (7)   0.0088 (7)   −0.0063 (8)
  C2    0.0253 (9)    0.0384 (11)   0.0253 (9)    −0.0092 (7)   0.0078 (7)   0.0008 (8)
  C3    0.0343 (10)   0.0279 (9)    0.0243 (9)    −0.0102 (7)   0.0043 (8)   −0.0031 (8)
  C4    0.0291 (9)    0.0253 (8)    0.0215 (8)    −0.0022 (7)   0.0079 (7)   −0.0008 (7)
  C5    0.0196 (7)    0.0191 (8)    0.0213 (8)    0.0005 (6)    0.0061 (6)   0.0034 (6)
  C7    0.0168 (7)    0.0215 (8)    0.0202 (8)    −0.0008 (6)   0.0060 (6)   0.0027 (6)
  C8    0.0212 (7)    0.0253 (8)    0.0268 (9)    0.0037 (7)    0.0072 (7)   0.0020 (7)
  C9    0.0196 (8)    0.0314 (9)    0.0232 (8)    0.0047 (7)    0.0070 (7)   0.0027 (7)
  C12   0.0174 (7)    0.0329 (9)    0.0205 (8)    −0.0024 (7)   0.0041 (6)   0.0035 (7)
  C13   0.0217 (7)    0.0238 (8)    0.0196 (8)    −0.0022 (6)   0.0055 (6)   −0.0005 (6)
  C14   0.0173 (7)    0.0240 (8)    0.0158 (8)    0.0020 (6)    0.0044 (6)   0.0014 (6)
  C16   0.0188 (7)    0.0188 (7)    0.0190 (7)    −0.0015 (6)   0.0035 (6)   −0.0040 (6)
  C17   0.0262 (8)    0.0248 (8)    0.0274 (9)    0.0022 (7)    0.0097 (7)   0.0020 (7)
  C18   0.0271 (9)    0.0278 (9)    0.0346 (10)   0.0079 (7)    0.0079 (8)   0.0012 (8)
  C19   0.0210 (8)    0.0356 (10)   0.0302 (9)    0.0049 (7)    0.0096 (7)   −0.0046 (8)
  C20   0.0274 (9)    0.0375 (10)   0.0282 (9)    0.0030 (7)    0.0128 (8)   0.0046 (8)
  N1    0.0218 (7)    0.0269 (7)    0.0275 (8)    −0.0029 (6)   0.0089 (6)   −0.0051 (6)
  N4    0.0231 (7)    0.0290 (8)    0.0227 (7)    0.0031 (6)    0.0080 (6)   0.0027 (6)
  ----- ------------- ------------- ------------- ------------- ------------ -------------

Geometric parameters (Å, º) {#tablewrapgeomlong}
===========================

  ------------------- ------------- ----------------- -------------
  C6---O1             1.219 (2)     C1---H1           0.95
  C6---N2             1.351 (2)     C2---C3           1.375 (3)
  C6---C5             1.506 (2)     C2---H2           0.95
  C10---C9            1.509 (2)     C3---C4           1.388 (2)
  C10---H10A          0.98          C3---H3           0.95
  C10---H10B          0.98          C4---C5           1.381 (2)
  C10---H10C          0.98          C4---H4           0.95
  C10---H10D          0.98          C5---N1           1.336 (2)
  C10---H10E          0.98          C7---C8           1.391 (2)
  C10---H10F          0.98          C7---C14          1.397 (2)
  C11---C12           1.507 (2)     C8---C9           1.384 (2)
  C11---H11A          0.98          C8---H8           0.95
  C11---H11B          0.98          C9---C12          1.394 (2)
  C11---H11C          0.98          C12---C13         1.395 (2)
  C11---H11D          0.98          C13---C14         1.384 (2)
  C11---H11E          0.98          C13---H13         0.95
  C11---H11F          0.98          C16---N4          1.336 (2)
  C15---O2            1.2274 (19)   C16---C17         1.377 (2)
  C15---N3            1.342 (2)     C17---C18         1.392 (2)
  C15---C16           1.505 (2)     C17---H17         0.95
  N2---C7             1.410 (2)     C18---C19         1.374 (3)
  N2---H2\'           0.86 (2)      C18---H18         0.95
  N3---C14            1.421 (2)     C19---C20         1.378 (3)
  N3---H3\'           0.86 (2)      C19---H19         0.95
  C1---N1             1.338 (2)     C20---N4          1.333 (2)
  C1---C2             1.382 (3)     C20---H20         0.95
                                                      
  O1---C6---N2        125.78 (16)   C15---N3---H3\'   119.0 (13)
  O1---C6---C5        120.35 (15)   C14---N3---H3\'   117.3 (13)
  N2---C6---C5        113.87 (14)   N1---C1---C2      123.65 (17)
  C9---C10---H10A     109.5         N1---C1---H1      118.2
  C9---C10---H10B     109.5         C2---C1---H1      118.2
  H10A---C10---H10B   109.5         C3---C2---C1      118.80 (16)
  C9---C10---H10C     109.5         C3---C2---H2      120.6
  H10A---C10---H10C   109.5         C1---C2---H2      120.6
  H10B---C10---H10C   109.5         C2---C3---C4      118.66 (16)
  C9---C10---H10D     109.5         C2---C3---H3      120.7
  H10A---C10---H10D   141.1         C4---C3---H3      120.7
  H10B---C10---H10D   56.3          C5---C4---C3      118.40 (16)
  H10C---C10---H10D   56.3          C5---C4---H4      120.8
  C9---C10---H10E     109.5         C3---C4---H4      120.8
  H10A---C10---H10E   56.3          N1---C5---C4      123.82 (14)
  H10B---C10---H10E   141.1         N1---C5---C6      117.49 (14)
  H10C---C10---H10E   56.3          C4---C5---C6      118.67 (15)
  H10D---C10---H10E   109.5         C8---C7---C14     118.66 (14)
  C9---C10---H10F     109.5         C8---C7---N2      122.39 (15)
  H10A---C10---H10F   56.3          C14---C7---N2     118.93 (14)
  H10B---C10---H10F   56.3          C9---C8---C7      121.53 (15)
  H10C---C10---H10F   141.1         C9---C8---H8      119.2
  H10D---C10---H10F   109.5         C7---C8---H8      119.2
  H10E---C10---H10F   109.5         C8---C9---C12     120.01 (15)
  C12---C11---H11A    109.5         C8---C9---C10     118.66 (16)
  C12---C11---H11B    109.5         C12---C9---C10    121.33 (16)
  H11A---C11---H11B   109.5         C9---C12---C13    118.41 (15)
  C12---C11---H11C    109.5         C9---C12---C11    121.62 (16)
  H11A---C11---H11C   109.5         C13---C12---C11   119.96 (16)
  H11B---C11---H11C   109.5         C14---C13---C12   121.65 (15)
  C12---C11---H11D    109.5         C14---C13---H13   119.2
  H11A---C11---H11D   141.1         C12---C13---H13   119.2
  H11B---C11---H11D   56.3          C13---C14---C7    119.73 (14)
  H11C---C11---H11D   56.3          C13---C14---N3    120.85 (14)
  C12---C11---H11E    109.5         C7---C14---N3     119.42 (13)
  H11A---C11---H11E   56.3          N4---C16---C17    123.97 (15)
  H11B---C11---H11E   141.1         N4---C16---C15    117.22 (14)
  H11C---C11---H11E   56.3          C17---C16---C15   118.74 (14)
  H11D---C11---H11E   109.5         C16---C17---C18   118.08 (16)
  C12---C11---H11F    109.5         C16---C17---H17   121
  H11A---C11---H11F   56.3          C18---C17---H17   121
  H11B---C11---H11F   56.3          C19---C18---C17   118.40 (17)
  H11C---C11---H11F   141.1         C19---C18---H18   120.8
  H11D---C11---H11F   109.5         C17---C18---H18   120.8
  H11E---C11---H11F   109.5         C18---C19---C20   119.32 (16)
  O2---C15---N3       124.85 (15)   C18---C19---H19   120.3
  O2---C15---C16      120.91 (14)   C20---C19---H19   120.3
  N3---C15---C16      114.22 (14)   N4---C20---C19    123.20 (17)
  C6---N2---C7        126.56 (14)   N4---C20---H20    118.4
  C6---N2---H2\'      113.8 (13)    C19---C20---H20   118.4
  C7---N2---H2\'      119.5 (13)    C5---N1---C1      116.67 (14)
  C15---N3---C14      123.74 (14)   C20---N4---C16    117.01 (15)
  ------------------- ------------- ----------------- -------------

Hydrogen-bond geometry (Å, º) {#tablewraphbondslong}
=============================

  ------------------- ---------- ---------- ------------- ---------------
  *D*---H···*A*       *D*---H    H···*A*    *D*···*A*     *D*---H···*A*
  N2---H2′···N1       0.86 (2)   2.20 (2)   2.6698 (19)   114.2 (16)
  N2---H2′···N3       0.86 (2)   2.48 (2)   2.777 (2)     101.2 (15)
  N2---H2′···O2^i^    0.86 (2)   2.60 (2)   3.2112 (19)   129.0 (17)
  N3---H3′···O2^i^    0.86 (2)   2.05 (2)   2.8508 (19)   155.5 (18)
  N3---H3′···N4       0.86 (2)   2.28 (2)   2.6670 (19)   107.8 (15)
  C8---H8···O1        0.95       2.31       2.877 (2)     118
  C2---H2···O1^ii^    0.95       2.59       3.195 (2)     122
  C3---H3···O2^iii^   0.95       2.48       3.160 (2)     128
  ------------------- ---------- ---------- ------------- ---------------

Symmetry codes: (i) *x*, −*y*+1, *z*−1/2; (ii) *x*+1/2, −*y*+3/2, *z*−1/2; (iii) *x*+1/2, *y*+1/2, *z*.

###### Hydrogen-bond geometry (Å, °)

  *D*---H⋯*A*      *D*---H    H⋯*A*      *D*⋯*A*       *D*---H⋯*A*
  ---------------- ---------- ---------- ------------- -------------
  N2---H2′⋯N1      0.86 (2)   2.20 (2)   2.6698 (19)   114.2 (16)
  N2---H2′⋯N3      0.86 (2)   2.48 (2)   2.777 (2)     101.2 (15)
  N2---H2′⋯O2^i^   0.86 (2)   2.60 (2)   3.2112 (19)   129.0 (17)
  N3---H3′⋯O2^i^   0.86 (2)   2.05 (2)   2.8508 (19)   155.5 (18)
  N3---H3′⋯N4      0.86 (2)   2.28 (2)   2.6670 (19)   107.8 (15)

Symmetry code: (i) .
