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

For bond-length data, see: Allen *et al.* ( 1987[@bb1]).  For hydrogen-bond motifs, see: Bernstein *et al.* ( 1995[@bb2]).  For details of the biological properties of compounds containing tetra­mic acid, see for example: Iida *et al.* ( 1986[@bb4]); Matkhalikova *et al.* ( 1969[@bb5]); Reddy & Rao (2006[@bb6]); Reiner (2007[@bb7]); Royles (1996[@bb8]).  For the syntheses of compounds containing tetra­mic acid units, see for example: Steglich (1989[@bb11]); Royles (1996[@bb8]). 

Experimental {#sec2}
============

 {#sec2.1}

### Crystal data {#sec2.1.1}

C~13~H~15~NO~6~·0.5H~2~O*M* *~r~* = 290.27Monoclinic,*a* = 22.7764 (12) Å*b* = 5.3046 (3) Å*c* = 13.0686 (6) Åβ = 117.612 (3)°*V* = 1399.11 (13) Å^3^*Z* = 4Mo *K*α radiationμ = 0.11 mm^−1^*T* = 100.0 (1) K0.41 × 0.19 × 0.04 mm

### Data collection {#sec2.1.2}

Bruker SMART APEX2 CCD area-detector diffractometerAbsorption correction: multi-scan (*SADABS*; Bruker, 2005[@bb3]) *T* ~min~ = 0.956, *T* ~max~ = 0.9969426 measured reflections2248 independent reflections1884 reflections with *I* \> 2σ(*I*)*R* ~int~ = 0.035

### Refinement {#sec2.1.3}

*R*\[*F* ^2^ \> 2σ(*F* ^2^)\] = 0.040*wR*(*F* ^2^) = 0.090*S* = 1.062248 reflections200 parameters1 restraintH atoms treated by a mixture of independent and constrained refinementΔρ~max~ = 0.39 e Å^−3^Δρ~min~ = −0.24 e Å^−3^

 {#d5e604}

Data collection: *APEX2* (Bruker, 2005[@bb3]); cell refinement: *APEX2*; data reduction: *SAINT* (Bruker, 2005[@bb3]); program(s) used to solve structure: *SHELXTL* (Sheldrick, 2008[@bb9]); program(s) used to refine structure: *SHELXTL*; molecular graphics: *SHELXTL*; software used to prepare material for publication: *SHELXTL* and *PLATON* (Spek, 2003[@bb10]). 

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

Crystal structure: contains datablocks global, I. DOI: [10.1107/S1600536808005552/sj2467sup1.cif](http://dx.doi.org/10.1107/S1600536808005552/sj2467sup1.cif)

Structure factors: contains datablocks I. DOI: [10.1107/S1600536808005552/sj2467Isup2.hkl](http://dx.doi.org/10.1107/S1600536808005552/sj2467Isup2.hkl)

Additional supplementary materials: [crystallographic information](http://scripts.iucr.org/cgi-bin/sendsupfiles?sj2467&file=sj2467sup0.html&mime=text/html); [3D view](http://scripts.iucr.org/cgi-bin/sendcif?sj2467sup1&Qmime=cif); [checkCIF report](http://scripts.iucr.org/cgi-bin/paper?sj2467&checkcif=yes)

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: [SJ2467](http://scripts.iucr.org/cgi-bin/sendsup?sj2467)). 

The authors acknowledge the generous support of both the Universiti Teknologi MARA and the Universiti Sains Malaysia as well as the financial support of the Ministry of Science, Technology and Innovation (E-Science grant No.  SF0050--02-01--01).  HKF and SC thank the Malaysian Government and Universiti Sains Malaysia for the Scientific Advancement Grant Allocation (SAGA) grant No.  304/PFIZIK/653003/A118. 

Comment
=======

Natural products containing tetramic acid goups continue to attract the interest of chemists and biologists due to their challenging structures and remarkable biological properties (Iida *et al.*,  1986; Matkhalikova *et al.*,  1969; Reddy & Rao, 2006; Reiner, 2007; Royles, 1996).  Among these, tetramic acids carrying an aromatic substituent on the ring are rarely found in nature (Reddy & Rao, 2006).  The title compound, C~13~H~15~NO~6~, can act as an essential intermediate in the synthesis of compounds responsible for the orange-yellow colour of plasmodia from *Leocarpus fragilis* (Steglich, 1989; Royles, 1995).  We have synthesized the title compound and its structure is reported here. 

The asymmetric unit of the title compound contains one molecule of C~13~H~15~NO~6~ and half an H~2~O molecule with the O1W atom lying on a twofold rotation axis, (Fig.  1).  The methoxycarbonylmethyl \[C4/C5/C7/O3/O5\] and the C3/N1/C4 amino sections of the molecule are essentially coplanar with a dihedral angle of 3.12 (10)° between them.  An intramolecular N1---H1N1···O3 hydrogen bond (Fig.  1) generates an S(5) ring motif (Bernstein *et al.*,  1995) and contributes to this planarity. 

In the 3-oxopropanoate moiety \[C1--C3/C6/O1/O2/O4\], atoms C1, C2, C6, O1 and O4 lie on the same plane with C1 deviating by a maximum of -0.017 (2) Å. Similarly atoms C3, O2, C4, C5, N1 and O3 lie on the same plane with the maximum deviation -0.058 (2) Å for C4.  The dihedral angle between these two planes is 70.29 (11) Å. The methoxycarbonylmethyl moiety makes a dihedral angle of 79.73 (10) Å with the hydroxyphenyl ring.  The water molecule links with the C~13~H~15~NO~6~ molecule *via* an N1---H1N1···O1W hydrogen bond (Fig.  1).  All bond lengths and angles show normal values (Allen *et al.*,  1987). 

In the crystal packing (Fig.  2), the molecules are stacked down both the \[010\] and \[102\] directions forming a two dimensional network parallel to the (-2 0 1) plane *via* N---H···O, O---H···O hydrogen bonds and weak C---H···O interactions (Table 1).  The crystal is further stablized by C---H···π interactions (Table 1); *Cg*~1~ is the centroid of the C8--C13 phenyl ring. 

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

The title compound was synthesized *via* condensation between an equimolar amount of hydroxyphenylglycine methylester (10.0 g, 60 mmol) and methylmalonate potassium salt (9.4 g, 60 mmol) in acetonitrile/water (140:40 ml) at 273 K. The mixture was stirred for 2 h in the presence of dicyclohexylcarbodiimide, which acted as a catalyst and a peptide-coupling agent.  The white precipitate formed during the reaction was filtered and washed thoroughly with dichloromethane.  The filtrate and the dichloromethane were combined and evaporated.  The resulting crude product was partitioned between water and dichloromethane, and the dichloromethane extract was dried over anhydrous magnesium sulfate and evaporated.  Colorless needle-shaped single crystals suitable for *X*-ray structure determination were obtained by slow evaporation of dichloromethane/petroleum ether (5:1 *v*/*v*) solution after several days (10.93 g, 65%). 

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

The amino, hydroxyl and water hydrogen atoms were located in a difference map and refined isotropically.  Hydrogen atoms attached to the carbon atoms were constrained in a riding motion approximation with d(C---H) = 0.93 Å, *U*~iso~=1.2*U*~eq~(C) for aromatic, 0.98 Å, *U*~iso~ = 1.2*U*~eq~(C) for CH, 0.97 Å, *U*~iso~ = 1.2*U*~eq~(C) for CH~2~, 0.96 Å, *U*~iso~ = 1.5*U*~eq~(C) for CH~3~ atoms.  A rotating group model was used for the methyl groups.  In the absence of significant anomalous scattering effects, a total of 1388 Friedel pairs were merged before final refinement. 

Figures
=======

![ The molecular structure of (I), showing 50% probability displacement ellipsoids and the atomic numbering.  N---H···O hydrogen bonds are drawn as dashed lines.](e-64-0o663-fig1){#Fap1}

![ The crystal packing of (I), viewed along the \[102\] direction.  Hydrogen bonds are drawn as dashed lines.](e-64-0o663-fig2){#Fap2}

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

  -------------------------- ---------------------------------------
  C~13~H~15~NO~6~·0.5H~2~O   *F*~000~ = 612
  *M~r~* = 290.27            *D*~x~ = 1.378 Mg m^−3^
  Monoclinic, *C*2           Mo *K*α radiation λ = 0.71073 Å
  Hall symbol: C 2y          Cell parameters from 2248 reflections
  *a* = 22.7764 (12) Å       θ = 1.8--30.0º
  *b* = 5.3046 (3) Å         µ = 0.11 mm^−1^
  *c* = 13.0686 (6) Å        *T* = 100.0 (1) K
  β = 117.612 (3)º           Needle, colorless
  *V* = 1399.11 (13) Å^3^    0.41 × 0.19 × 0.04 mm
  *Z* = 4                    
  -------------------------- ---------------------------------------

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

  --------------------------------------------------------- --------------------------------------
  Bruker SMART APEX2 CCD area-detector diffractometer       2248 independent reflections
  Radiation source: fine-focus sealed tube                  1884 reflections with *I* \> 2σ(*I*)
  Monochromator: graphite                                   *R*~int~ = 0.035
  Detector resolution: 8.33 pixels mm^-1^                   θ~max~ = 30.0º
  *T* = 100.0(1) K                                          θ~min~ = 1.8º
  ω scans                                                   *h* = −29→31
  Absorption correction: multi-scan(SADABS; Bruker, 2005)   *k* = −7→7
  *T*~min~ = 0.956, *T*~max~ = 0.996                        *l* = −18→18
  9426 measured reflections                                 
  --------------------------------------------------------- --------------------------------------

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

  ---------------------------------------------------------------- ---------------------------------------------------------------------------------------------------
  Refinement on *F*^2^                                             Secondary atom site location: difference Fourier map
  Least-squares matrix: full                                       Hydrogen site location: inferred from neighbouring sites
  *R*\[*F*^2^ \> 2σ(*F*^2^)\] = 0.040                              H atoms treated by a mixture of independent and constrained refinement
  *wR*(*F*^2^) = 0.090                                               *w* = 1/\[σ^2^(*F*~o~^2^) + (0.0406*P*)^2^ + 0.4523*P*\] where *P* = (*F*~o~^2^ + 2*F*~c~^2^)/3
  *S* = 1.06                                                       (Δ/σ)~max~ \< 0.001
  2248 reflections                                                 Δρ~max~ = 0.39 e Å^−3^
  200 parameters                                                   Δρ~min~ = −0.24 e Å^−3^
  1 restraint                                                      Extinction correction: none
  Primary atom site location: structure-invariant direct methods   
  ---------------------------------------------------------------- ---------------------------------------------------------------------------------------------------

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

  -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  Experimental.  The data was collected with the Oxford Cyrosystem Cobra low-temperature attachment. 
  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^) {#tablewrapcoords}
==================================================================================================

  ------ -------------- ------------ --------------- -------------------- --
         *x*            *y*          *z*             *U*~iso~\*/*U*~eq~   
  O1W    0.5000         0.8858 (5)   0.5000          0.0242 (5)           
  H1W    0.4734 (14)    0.998 (7)    0.518 (2)       0.058 (9)\*          
  O1     0.41331 (9)    0.1694 (5)   0.55170 (15)    0.0512 (6)           
  O2     0.36387 (7)    0.1785 (3)   0.28492 (11)    0.0255 (3)           
  O3     0.51628 (9)    0.7925 (4)   0.27318 (16)    0.0435 (5)           
  O4     0.32338 (7)    0.3629 (4)   0.53519 (12)    0.0311 (4)           
  O5     0.52565 (7)    0.5121 (3)   0.15432 (12)    0.0250 (3)           
  O6     0.23720 (7)    0.3718 (3)   −0.23284 (11)   0.0232 (3)           
  H1O6   0.2058 (14)    0.488 (7)    −0.250 (2)      0.046 (8)\*          
  N1     0.43133 (8)    0.5081 (4)   0.31026 (13)    0.0196 (4)           
  H1N1   0.4513 (13)    0.650 (6)    0.351 (2)       0.039 (7)\*          
  C1     0.37123 (10)   0.3244 (4)   0.50613 (16)    0.0231 (5)           
  C2     0.36758 (10)   0.5050 (5)   0.41546 (17)    0.0239 (4)           
  H2A    0.3963         0.6477       0.4522          0.029\*              
  H2B    0.3226         0.5676       0.3728          0.029\*              
  C3     0.38810 (9)    0.3812 (5)   0.33240 (15)    0.0201 (4)           
  C4     0.44916 (9)    0.4168 (4)   0.22326 (14)    0.0178 (4)           
  H4     0.4684         0.2479       0.2450          0.021\*              
  C5     0.50120 (10)   0.5952 (4)   0.22279 (16)    0.0213 (4)           
  C6     0.32471 (12)   0.1992 (6)   0.62502 (18)    0.0382 (6)           
  H6A    0.3150         0.0295       0.5966          0.057\*              
  H6B    0.2921         0.2546       0.6473          0.057\*              
  H6C    0.3678         0.2051       0.6907          0.057\*              
  C7     0.57232 (10)   0.6792 (5)   0.14299 (18)    0.0275 (5)           
  H7A    0.5530         0.8438       0.1209          0.041\*              
  H7B    0.5831         0.6152       0.0850          0.041\*              
  H7C    0.6119         0.6897       0.2155          0.041\*              
  C8     0.39035 (9)    0.4061 (4)   0.10253 (14)    0.0173 (4)           
  C9     0.34208 (9)    0.5916 (4)   0.06352 (15)    0.0185 (4)           
  H9     0.3447         0.7234       0.1124          0.022\*              
  C10    0.28956 (9)    0.5828 (4)   −0.04846 (15)   0.0186 (4)           
  H10    0.2571         0.7071       −0.0738         0.022\*              
  C11    0.28619 (9)    0.3874 (4)   −0.12164 (14)   0.0171 (4)           
  C12    0.33391 (9)    0.1994 (4)   −0.08248 (15)   0.0202 (4)           
  H12    0.3312         0.0669       −0.1311         0.024\*              
  C13    0.38579 (9)    0.2087 (4)   0.02927 (15)    0.0189 (4)           
  H13    0.4177         0.0820       0.0552          0.023\*              
  ------ -------------- ------------ --------------- -------------------- --

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

  ----- ------------- ------------- ------------- -------------- ------------- --------------
        *U*^11^       *U*^22^       *U*^33^       *U*^12^        *U*^13^       *U*^23^
  O1W   0.0252 (10)   0.0249 (12)   0.0262 (9)    0.000          0.0151 (9)    0.000
  O1    0.0576 (11)   0.0695 (15)   0.0432 (9)    0.0427 (12)    0.0373 (9)    0.0351 (11)
  O2    0.0250 (7)    0.0272 (8)    0.0224 (6)    −0.0058 (7)    0.0094 (6)    0.0016 (7)
  O3    0.0540 (11)   0.0432 (12)   0.0547 (11)   −0.0279 (9)    0.0432 (10)   −0.0289 (9)
  O4    0.0244 (7)    0.0455 (11)   0.0303 (7)    0.0075 (8)     0.0185 (6)    0.0128 (8)
  O5    0.0257 (7)    0.0254 (8)    0.0320 (7)    −0.0051 (7)    0.0204 (6)    −0.0065 (7)
  O6    0.0202 (7)    0.0268 (9)    0.0176 (6)    0.0031 (7)     0.0046 (5)    −0.0047 (6)
  N1    0.0196 (8)    0.0240 (9)    0.0163 (7)    −0.0034 (8)    0.0093 (6)    −0.0012 (7)
  C1    0.0205 (10)   0.0301 (13)   0.0188 (8)    0.0034 (9)     0.0093 (7)    0.0033 (8)
  C2    0.0220 (9)    0.0286 (11)   0.0240 (9)    0.0026 (9)     0.0132 (8)    0.0046 (9)
  C3    0.0159 (8)    0.0270 (11)   0.0148 (7)    0.0007 (9)     0.0048 (7)    0.0048 (9)
  C4    0.0174 (8)    0.0200 (10)   0.0166 (7)    −0.0016 (8)    0.0083 (7)    −0.0003 (8)
  C5    0.0200 (9)    0.0237 (11)   0.0199 (8)    −0.0016 (9)    0.0091 (7)    −0.0025 (9)
  C6    0.0391 (13)   0.0542 (17)   0.0285 (10)   −0.0056 (14)   0.0218 (10)   0.0085 (13)
  C7    0.0255 (10)   0.0311 (12)   0.0337 (10)   −0.0055 (10)   0.0203 (9)    −0.0048 (10)
  C8    0.0175 (8)    0.0181 (10)   0.0175 (7)    −0.0034 (8)    0.0091 (7)    0.0017 (8)
  C9    0.0218 (9)    0.0178 (10)   0.0184 (8)    −0.0006 (8)    0.0115 (7)    −0.0022 (8)
  C10   0.0191 (9)    0.0168 (10)   0.0208 (8)    0.0018 (8)     0.0099 (7)    0.0011 (8)
  C11   0.0157 (8)    0.0187 (10)   0.0168 (7)    −0.0006 (8)    0.0074 (7)    0.0003 (8)
  C12   0.0233 (10)   0.0183 (10)   0.0196 (8)    −0.0002 (9)    0.0105 (8)    −0.0030 (8)
  C13   0.0182 (9)    0.0174 (10)   0.0211 (8)    0.0011 (8)     0.0092 (7)    0.0000 (8)
  ----- ------------- ------------- ------------- -------------- ------------- --------------

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

  ------------------- -------------- ----------------------- --------------
  O1W---H1W           0.95 (3)       C4---C8                 1.526 (2)
  O1---C1             1.192 (3)      C4---H4                 0.9800
  O2---C3             1.236 (3)      C6---H6A                0.9600
  O3---C5             1.199 (3)      C6---H6B                0.9600
  O4---C1             1.326 (2)      C6---H6C                0.9600
  O4---C6             1.449 (3)      C7---H7A                0.9600
  O5---C5             1.329 (3)      C7---H7B                0.9600
  O5---C7             1.443 (3)      C7---H7C                0.9600
  O6---C11            1.364 (2)      C8---C9                 1.385 (3)
  O6---H1O6           0.89 (3)       C8---C13                1.390 (3)
  N1---C3             1.331 (3)      C9---C10                1.397 (2)
  N1---C4             1.456 (2)      C9---H9                 0.9300
  N1---H1N1           0.91 (3)       C10---C11               1.388 (3)
  C1---C2             1.496 (3)      C10---H10               0.9300
  C2---C3             1.516 (3)      C11---C12               1.386 (3)
  C2---H2A            0.9700         C12---C13               1.390 (2)
  C2---H2B            0.9700         C12---H12               0.9300
  C4---C5             1.519 (3)      C13---H13               0.9300
                                                             
  C1---O4---C6        115.36 (18)    H6A---C6---H6B          109.5
  C5---O5---C7        115.06 (18)    O4---C6---H6C           109.5
  C11---O6---H1O6     112.7 (18)     H6A---C6---H6C          109.5
  C3---N1---C4        120.25 (18)    H6B---C6---H6C          109.5
  C3---N1---H1N1      120.7 (17)     O5---C7---H7A           109.5
  C4---N1---H1N1      119.0 (17)     O5---C7---H7B           109.5
  O1---C1---O4        122.7 (2)      H7A---C7---H7B          109.5
  O1---C1---C2        125.06 (19)    O5---C7---H7C           109.5
  O4---C1---C2        112.13 (18)    H7A---C7---H7C          109.5
  C1---C2---C3        111.5 (2)      H7B---C7---H7C          109.5
  C1---C2---H2A       109.3          C9---C8---C13           119.26 (16)
  C3---C2---H2A       109.3          C9---C8---C4            121.39 (18)
  C1---C2---H2B       109.3          C13---C8---C4           119.34 (18)
  C3---C2---H2B       109.3          C8---C9---C10           120.66 (18)
  H2A---C2---H2B      108.0          C8---C9---H9            119.7
  O2---C3---N1        122.28 (19)    C10---C9---H9           119.7
  O2---C3---C2        121.48 (19)    C11---C10---C9          119.58 (18)
  N1---C3---C2        116.2 (2)      C11---C10---H10         120.2
  N1---C4---C5        107.25 (16)    C9---C10---H10          120.2
  N1---C4---C8        113.02 (16)    O6---C11---C12          117.66 (18)
  C5---C4---C8        109.38 (15)    O6---C11---C10          122.39 (18)
  N1---C4---H4        109.0          C12---C11---C10         119.95 (16)
  C5---C4---H4        109.0          C11---C12---C13         120.13 (19)
  C8---C4---H4        109.0          C11---C12---H12         119.9
  O3---C5---O5        123.8 (2)      C13---C12---H12         119.9
  O3---C5---C4        124.54 (19)    C12---C13---C8          120.40 (19)
  O5---C5---C4        111.55 (18)    C12---C13---H13         119.8
  O4---C6---H6A       109.5          C8---C13---H13          119.8
  O4---C6---H6B       109.5                                  
                                                             
  C6---O4---C1---O1   −1.3 (3)       C8---C4---C5---O5       −63.6 (2)
  C6---O4---C1---C2   −178.40 (19)   N1---C4---C8---C9       38.6 (3)
  O1---C1---C2---C3   38.6 (3)       C5---C4---C8---C9       −80.8 (2)
  O4---C1---C2---C3   −144.42 (18)   N1---C4---C8---C13      −142.68 (19)
  C4---N1---C3---O2   3.3 (3)        C5---C4---C8---C13      97.9 (2)
  C4---N1---C3---C2   −174.03 (16)   C13---C8---C9---C10     −0.5 (3)
  C1---C2---C3---O2   50.6 (2)       C4---C8---C9---C10      178.14 (18)
  C1---C2---C3---N1   −132.06 (19)   C8---C9---C10---C11     −0.7 (3)
  C3---N1---C4---C5   −177.48 (17)   C9---C10---C11---O6     −178.20 (18)
  C3---N1---C4---C8   61.9 (2)       C9---C10---C11---C12    1.5 (3)
  C7---O5---C5---O3   −0.6 (3)       O6---C11---C12---C13    178.59 (19)
  C7---O5---C5---C4   176.08 (16)    C10---C11---C12---C13   −1.2 (3)
  N1---C4---C5---O3   −10.0 (3)      C11---C12---C13---C8    −0.1 (3)
  C8---C4---C5---O3   113.0 (2)      C9---C8---C13---C12     0.9 (3)
  N1---C4---C5---O5   173.45 (16)    C4---C8---C13---C12     −177.78 (18)
  ------------------- -------------- ----------------------- --------------

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

  --------------------- ---------- ---------- ----------- ---------------
  *D*---H···*A*         *D*---H    H···*A*    *D*···*A*   *D*---H···*A*
  O1W---H1W···O1^i^     0.95 (4)   1.86 (3)   2.803 (3)   170 (3)
  N1---H1N1···O1W       0.91 (3)   2.14 (3)   3.002 (3)   157 (2)
  N1---H1N1···O3        0.91 (3)   2.28 (3)   2.669 (3)   105 (2)
  O6---H1O6···O2^ii^    0.89 (4)   1.75 (3)   2.638 (2)   171 (3)
  C2---H2A···O1W        0.97       2.49       3.363 (3)   150
  C2---H2B···O6^ii^     0.97       2.34       3.146 (3)   140
  C6---H6B···O6^iii^    0.96       2.49       3.420 (3)   162
  C7---H7B···Cg1^iv^    0.96       2.68       3.574 (3)   155
  C10---H10···Cg1^ii^   0.93       3.01       3.717 (2)   134
  --------------------- ---------- ---------- ----------- ---------------

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

###### Hydrogen-bond geometry (Å, °)

  *D*---H⋯*A*            *D*---H    H⋯*A*      *D*⋯*A*     *D*---H⋯*A*
  ---------------------- ---------- ---------- ----------- -------------
  O1*W*---H1*W*⋯O1^i^    0.95 (4)   1.86 (3)   2.803 (3)   170 (3)
  N1---H1*N*1⋯O1*W*      0.91 (3)   2.14 (3)   3.002 (3)   157 (2)
  N1---H1*N*1⋯O3         0.91 (3)   2.28 (3)   2.669 (3)   105 (2)
  O6---H1*O*6⋯O2^ii^     0.89 (4)   1.75 (3)   2.638 (2)   171 (3)
  C2---H2*A*⋯O1*W*       0.97       2.49       3.363 (3)   150
  C2---H2*B*⋯O6^ii^      0.97       2.34       3.146 (3)   140
  C6---H6*B*⋯O6^iii^     0.96       2.49       3.420 (3)   162
  C7---H7*B*⋯*Cg*1^iv^   0.96       2.68       3.574 (3)   155
  C10---H10⋯*Cg*1^ii^    0.93       3.01       3.717 (2)   134

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) . * Cg*1 is the centroid of the C8--C13 phenyl ring. 

[^1]: Additional correspondence author, e-mail: suchada.c\@psu.ac.th.