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

The chemistry of aroylhydrazones continues to attract much attention due to their ability to coordinate to metal ions (Singh *et al.*, 1982[@bb6]; Salem, 1998[@bb3]) and their biological activity (Singh *et al.*, 1982[@bb6]; Carcelli *et al.*, 1995[@bb2]).

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

 {#sec2.1}

### Crystal data {#sec2.1.1}

C~20~H~14~BrClN~2~O~2~*M* *~r~* = 429.69Triclinic,*a* = 7.3664 (8) Å*b* = 10.6894 (11) Å*c* = 12.3029 (14) Åα = 71.976 (2)°β = 82.228 (2)°γ = 85.466 (2)°*V* = 912.05 (17) Å^3^*Z* = 2Mo *K*α radiationμ = 2.42 mm^−1^*T* = 273 K0.20 × 0.16 × 0.13 mm

### Data collection {#sec2.1.2}

Bruker SMART area-detector diffractometerAbsorption correction: multi-scan (*SADABS*; Sheldrick, 1996[@bb4]) *T* ~min~ = 0.644, *T* ~max~ = 0.7444841 measured reflections3189 independent reflections2467 reflections with *I* \> 2σ(*I*)*R* ~int~ = 0.015

### Refinement {#sec2.1.3}

*R*\[*F* ^2^ \> 2σ(*F* ^2^)\] = 0.034*wR*(*F* ^2^) = 0.085*S* = 1.043189 reflections237 parametersH-atom parameters constrainedΔρ~max~ = 0.32 e Å^−3^Δρ~min~ = −0.44 e Å^−3^

 {#d5e406}

Data collection: *SMART* (Bruker, 1996[@bb1]); cell refinement: *SAINT* (Bruker, 1996[@bb1]); data reduction: *SAINT*; program(s) used to solve structure: *SHELXS97* (Sheldrick, 2008[@bb5]); program(s) used to refine structure: *SHELXL97* (Sheldrick, 2008[@bb5]); molecular graphics: *SHELXTL* (Sheldrick, 2008[@bb5]); software used to prepare material for publication: *SHELXTL*.

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

Crystal structure: contains datablocks I, global. DOI: [10.1107/S1600536809027949/ng2613sup1.cif](http://dx.doi.org/10.1107/S1600536809027949/ng2613sup1.cif)

Structure factors: contains datablocks I. DOI: [10.1107/S1600536809027949/ng2613Isup2.hkl](http://dx.doi.org/10.1107/S1600536809027949/ng2613Isup2.hkl)

Additional supplementary materials: [crystallographic information](http://scripts.iucr.org/cgi-bin/sendsupfiles?ng2613&file=ng2613sup0.html&mime=text/html); [3D view](http://scripts.iucr.org/cgi-bin/sendcif?ng2613sup1&Qmime=cif); [checkCIF report](http://scripts.iucr.org/cgi-bin/paper?ng2613&checkcif=yes)

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: [NG2613](http://scripts.iucr.org/cgi-bin/sendsup?ng2613)).

This project was supported by the Postgraduate Foundation of Xi'an Polytechnic University (grant No. Y05--2--09).

Comment
=======

The chemistry of aroylhydrazones continues to attract much attention due to their coordination ability to metal ions (Singh *et al.*, 1982; Salem, 1998) and their biological activity (Singh *et al.*, 1982; Carcelli *et al.*, 1995). As an extension of work on the structural characterization of aroylhydrazone derivatives,the title compound, (I),was synthesized and its crystal structure is reported here.

The title molecule displays a *trans* conformation with respect to the C7=N1 double bond (Fig. 1). The crystal structure is stabilized by intramolecular O---H···N hydrogen bonds (Table).

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

4-chlorobenzohydrazide(0.02 mol,3.42 g) was dissolved in anhydrous ethanol (50 ml), and 1-(5-bromo-2-hydroxyphenyl)ethanone (0.02 mol, 4.30 g) was added. The reaction mixture was refluxed for 6 h with stirring, then the resulting precipitate was collected by filtration, washed several times with ethanol and dried *in vacuo* (yield 85%). The compound (2.0 mmol,0.68 g) was dissolved in dimethylformamide (30 ml) and kept at room temperature for 30 d to obtain yellow single crystals suitable for X-ray diffraction.

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

All H atoms were positioned geometrically and treated as riding on their parent atoms,with C---H(aromatic) = 0.93 Å, O---H = 0.82 Å, and N---H = 0.86 Å and with *U*~iso~(H) =1.2*U*~eq~(C~aromatic~,*N*).

Figures
=======

![The molecular structure of compound (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.](e-65-o1944-fig1){#Fap1}

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

  ------------------------ ---------------------------------------
  C~20~H~14~BrClN~2~O~2~   *Z* = 2
  *M~r~* = 429.69          *F*(000) = 432
  Triclinic, *P*1          *D*~x~ = 1.565 Mg m^−3^
  Hall symbol: -P 1        Mo *K*α radiation, λ = 0.71073 Å
  *a* = 7.3664 (8) Å       Cell parameters from 1806 reflections
  *b* = 10.6894 (11) Å     θ = 2.8--25.3°
  *c* = 12.3029 (14) Å     µ = 2.42 mm^−1^
  α = 71.976 (2)°          *T* = 273 K
  β = 82.228 (2)°          Block, yellow
  γ = 85.466 (2)°          0.20 × 0.16 × 0.13 mm
  *V* = 912.05 (17) Å^3^   
  ------------------------ ---------------------------------------

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

  --------------------------------------------------------------- --------------------------------------
  Bruker SMART area-detector diffractometer                       3189 independent reflections
  Radiation source: fine-focus sealed tube                        2467 reflections with *I* \> 2σ(*I*)
  graphite                                                        *R*~int~ = 0.015
  φ and ω scans                                                   θ~max~ = 25.1°, θ~min~ = 1.8°
  Absorption correction: multi-scan (*SADABS*; Sheldrick, 1996)   *h* = −8→8
  *T*~min~ = 0.644, *T*~max~ = 0.744                              *k* = −8→12
  4841 measured reflections                                       *l* = −14→14
  --------------------------------------------------------------- --------------------------------------

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*\[*F*^2^ \> 2σ(*F*^2^)\] = 0.034   Hydrogen site location: inferred from neighbouring sites
  *wR*(*F*^2^) = 0.085                  H-atom parameters constrained
  *S* = 1.04                            *w* = 1/\[σ^2^(*F*~o~^2^) + (0.0366*P*)^2^ + 0.3768*P*\] where *P* = (*F*~o~^2^ + 2*F*~c~^2^)/3
  3189 reflections                      (Δ/σ)~max~ = 0.001
  237 parameters                        Δρ~max~ = 0.32 e Å^−3^
  0 restraints                          Δρ~min~ = −0.43 e Å^−3^
  ------------------------------------- -------------------------------------------------------------------------------------------------

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

  -----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
  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~   
  Br1   0.36717 (5)    1.17236 (4)    1.00467 (3)    0.06975 (17)         
  Cl1   0.08513 (13)   0.47987 (9)    0.23226 (8)    0.0729 (3)           
  O1    0.3069 (3)     1.25145 (19)   0.50596 (17)   0.0627 (6)           
  H1    0.2882         1.1830         0.4931         0.094\*              
  O2    0.2209 (3)     1.0374 (2)     0.33927 (17)   0.0587 (6)           
  N1    0.2632 (3)     1.0045 (2)     0.55663 (18)   0.0454 (6)           
  N2    0.2388 (3)     0.9007 (2)     0.51767 (19)   0.0480 (6)           
  H2    0.2367         0.8215         0.5636         0.058\*              
  C1    0.3457 (4)     1.1936 (3)     0.8483 (2)     0.0465 (7)           
  C2    0.3209 (4)     1.0858 (3)     0.8134 (2)     0.0432 (6)           
  H2A   0.3141         1.0027         0.8673         0.052\*              
  C3    0.3060 (3)     1.0998 (2)     0.6988 (2)     0.0389 (6)           
  C4    0.3189 (4)     1.2264 (3)     0.6188 (2)     0.0455 (7)           
  C5    0.3465 (4)     1.3328 (3)     0.6566 (3)     0.0540 (8)           
  H5    0.3564         1.4163         0.6036         0.065\*              
  C6    0.3595 (4)     1.3169 (3)     0.7695 (3)     0.0534 (8)           
  H6    0.3775         1.3891         0.7932         0.064\*              
  C7    0.2801 (4)     0.9829 (3)     0.6636 (2)     0.0397 (6)           
  C8    0.2759 (4)     0.8493 (2)     0.7500 (2)     0.0380 (6)           
  C9    0.4302 (4)     0.7655 (3)     0.7577 (2)     0.0474 (7)           
  H9    0.5367         0.7920         0.7083         0.057\*              
  C10   0.4261 (5)     0.6424 (3)     0.8389 (3)     0.0544 (8)           
  H10   0.5296         0.5861         0.8433         0.065\*              
  C11   0.2707 (5)     0.6030 (3)     0.9127 (3)     0.0524 (8)           
  H11   0.2690         0.5206         0.9677         0.063\*              
  C12   0.1173 (4)     0.6854 (3)     0.9054 (3)     0.0534 (8)           
  H12   0.0117         0.6586         0.9557         0.064\*              
  C13   0.1186 (4)     0.8074 (3)     0.8242 (2)     0.0485 (7)           
  H13   0.0134         0.8620         0.8190         0.058\*              
  C14   0.2180 (4)     0.9262 (3)     0.4043 (2)     0.0415 (6)           
  C15   0.1925 (4)     0.8100 (3)     0.3660 (2)     0.0394 (6)           
  C16   0.1873 (4)     0.6816 (3)     0.4374 (2)     0.0548 (8)           
  H16   0.2020         0.6634         0.5147         0.066\*              
  C17   0.1604 (5)     0.5797 (3)     0.3946 (3)     0.0593 (8)           
  H17   0.1600         0.4931         0.4423         0.071\*              
  C18   0.1345 (4)     0.6076 (3)     0.2821 (2)     0.0480 (7)           
  C19   0.1422 (4)     0.7332 (3)     0.2085 (3)     0.0555 (8)           
  H19   0.1275         0.7504         0.1312         0.067\*              
  C20   0.1724 (4)     0.8337 (3)     0.2515 (2)     0.0491 (7)           
  H20   0.1792         0.9193         0.2021         0.059\*              
  ----- -------------- -------------- -------------- -------------------- --

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

  ----- ------------- ------------- ------------- -------------- --------------- ---------------
        *U*^11^       *U*^22^       *U*^33^       *U*^12^        *U*^13^         *U*^23^
  Br1   0.0901 (3)    0.0740 (3)    0.0629 (2)    0.00901 (19)   −0.02581 (18)   −0.04231 (19)
  Cl1   0.0828 (6)    0.0743 (6)    0.0825 (6)    −0.0160 (5)    −0.0070 (5)     −0.0520 (5)
  O1    0.1015 (18)   0.0392 (12)   0.0457 (12)   −0.0063 (12)   −0.0087 (11)    −0.0094 (9)
  O2    0.0902 (16)   0.0397 (12)   0.0469 (12)   −0.0099 (11)   −0.0193 (11)    −0.0075 (10)
  N1    0.0639 (15)   0.0360 (13)   0.0407 (13)   −0.0063 (11)   −0.0108 (11)    −0.0149 (10)
  N2    0.0763 (17)   0.0328 (13)   0.0384 (12)   −0.0087 (11)   −0.0132 (11)    −0.0115 (10)
  C1    0.0478 (16)   0.0488 (18)   0.0520 (16)   0.0021 (13)    −0.0122 (13)    −0.0270 (14)
  C2    0.0476 (16)   0.0391 (15)   0.0463 (16)   −0.0007 (12)   −0.0086 (13)    −0.0167 (13)
  C3    0.0420 (15)   0.0330 (14)   0.0442 (15)   −0.0023 (11)   −0.0072 (12)    −0.0144 (12)
  C4    0.0516 (17)   0.0392 (16)   0.0470 (17)   −0.0034 (13)   −0.0054 (13)    −0.0149 (13)
  C5    0.068 (2)     0.0306 (15)   0.0629 (19)   −0.0036 (14)   −0.0084 (16)    −0.0122 (14)
  C6    0.0555 (18)   0.0443 (18)   0.072 (2)     −0.0012 (14)   −0.0137 (15)    −0.0313 (16)
  C7    0.0448 (15)   0.0379 (15)   0.0390 (15)   −0.0021 (12)   −0.0059 (12)    −0.0150 (12)
  C8    0.0512 (16)   0.0305 (14)   0.0368 (14)   −0.0066 (12)   −0.0078 (12)    −0.0143 (11)
  C9    0.0522 (18)   0.0433 (17)   0.0482 (16)   −0.0037 (14)   −0.0039 (13)    −0.0161 (13)
  C10   0.064 (2)     0.0395 (17)   0.0618 (19)   0.0082 (15)    −0.0187 (17)    −0.0169 (15)
  C11   0.077 (2)     0.0326 (16)   0.0472 (17)   −0.0099 (15)   −0.0152 (16)    −0.0066 (13)
  C12   0.063 (2)     0.0460 (18)   0.0503 (17)   −0.0166 (16)   −0.0007 (15)    −0.0128 (14)
  C13   0.0518 (18)   0.0431 (17)   0.0523 (17)   −0.0014 (13)   −0.0086 (14)    −0.0158 (14)
  C14   0.0458 (16)   0.0412 (17)   0.0382 (15)   −0.0038 (12)   −0.0082 (12)    −0.0109 (13)
  C15   0.0433 (15)   0.0388 (15)   0.0380 (14)   −0.0041 (12)   −0.0084 (12)    −0.0122 (12)
  C16   0.083 (2)     0.0445 (17)   0.0403 (16)   −0.0140 (15)   −0.0156 (15)    −0.0112 (13)
  C17   0.084 (2)     0.0423 (17)   0.0538 (19)   −0.0151 (16)   −0.0114 (17)    −0.0132 (14)
  C18   0.0465 (16)   0.0549 (19)   0.0530 (17)   −0.0078 (14)   −0.0055 (13)    −0.0300 (15)
  C19   0.069 (2)     0.064 (2)     0.0417 (16)   −0.0029 (16)   −0.0131 (14)    −0.0250 (15)
  C20   0.0633 (19)   0.0458 (17)   0.0373 (15)   −0.0027 (14)   −0.0085 (13)    −0.0102 (13)
  ----- ------------- ------------- ------------- -------------- --------------- ---------------

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

  -------------------- ------------ ----------------------- ------------
  Br1---C1             1.893 (3)    C8---C13                1.386 (4)
  Cl1---C18            1.740 (3)    C9---C10                1.384 (4)
  O1---C4              1.344 (3)    C9---H9                 0.9300
  O1---H1              0.8200       C10---C11               1.368 (4)
  O2---C14             1.210 (3)    C10---H10               0.9300
  N1---C7              1.285 (3)    C11---C12               1.372 (4)
  N1---N2              1.370 (3)    C11---H11               0.9300
  N2---C14             1.364 (3)    C12---C13               1.376 (4)
  N2---H2              0.8600       C12---H12               0.9300
  C1---C6              1.375 (4)    C13---H13               0.9300
  C1---C2              1.380 (4)    C14---C15               1.491 (4)
  C2---C3              1.390 (4)    C15---C20               1.378 (4)
  C2---H2A             0.9300       C15---C16               1.382 (4)
  C3---C4              1.407 (4)    C16---C17               1.385 (4)
  C3---C7              1.476 (3)    C16---H16               0.9300
  C4---C5              1.392 (4)    C17---C18               1.359 (4)
  C5---C6              1.363 (4)    C17---H17               0.9300
  C5---H5              0.9300       C18---C19               1.368 (4)
  C6---H6              0.9300       C19---C20               1.381 (4)
  C7---C8              1.493 (4)    C19---H19               0.9300
  C8---C9              1.385 (4)    C20---H20               0.9300
                                                            
  C4---O1---H1         109.5        C11---C10---H10         119.8
  C7---N1---N2         119.3 (2)    C9---C10---H10          119.8
  C14---N2---N1        118.3 (2)    C10---C11---C12         119.8 (3)
  C14---N2---H2        120.8        C10---C11---H11         120.1
  N1---N2---H2         120.8        C12---C11---H11         120.1
  C6---C1---C2         120.4 (3)    C11---C12---C13         120.4 (3)
  C6---C1---Br1        119.3 (2)    C11---C12---H12         119.8
  C2---C1---Br1        120.2 (2)    C13---C12---H12         119.8
  C1---C2---C3         120.9 (3)    C12---C13---C8          120.4 (3)
  C1---C2---H2A        119.6        C12---C13---H13         119.8
  C3---C2---H2A        119.6        C8---C13---H13          119.8
  C2---C3---C4         118.4 (2)    O2---C14---N2           121.2 (2)
  C2---C3---C7         119.9 (2)    O2---C14---C15          122.5 (2)
  C4---C3---C7         121.8 (2)    N2---C14---C15          116.3 (2)
  O1---C4---C5         117.2 (2)    C20---C15---C16         118.5 (3)
  O1---C4---C3         123.5 (2)    C20---C15---C14         117.1 (2)
  C5---C4---C3         119.3 (3)    C16---C15---C14         124.4 (2)
  C6---C5---C4         121.3 (3)    C15---C16---C17         120.5 (3)
  C6---C5---H5         119.3        C15---C16---H16         119.8
  C4---C5---H5         119.3        C17---C16---H16         119.8
  C5---C6---C1         119.7 (3)    C18---C17---C16         119.3 (3)
  C5---C6---H6         120.2        C18---C17---H17         120.4
  C1---C6---H6         120.2        C16---C17---H17         120.4
  N1---C7---C3         116.0 (2)    C17---C18---C19         121.8 (3)
  N1---C7---C8         123.7 (2)    C17---C18---Cl1         118.7 (2)
  C3---C7---C8         120.2 (2)    C19---C18---Cl1         119.5 (2)
  C9---C8---C13        118.9 (2)    C18---C19---C20         118.4 (3)
  C9---C8---C7         120.4 (2)    C18---C19---H19         120.8
  C13---C8---C7        120.7 (2)    C20---C19---H19         120.8
  C10---C9---C8        120.1 (3)    C15---C20---C19         121.5 (3)
  C10---C9---H9        120.0        C15---C20---H20         119.2
  C8---C9---H9         120.0        C19---C20---H20         119.2
  C11---C10---C9       120.4 (3)                            
                                                            
  C7---N1---N2---C14   178.9 (2)    C13---C8---C9---C10     −0.3 (4)
  C6---C1---C2---C3    −1.2 (4)     C7---C8---C9---C10      179.2 (3)
  Br1---C1---C2---C3   −179.6 (2)   C8---C9---C10---C11     −0.6 (4)
  C1---C2---C3---C4    0.7 (4)      C9---C10---C11---C12    0.7 (4)
  C1---C2---C3---C7    179.8 (2)    C10---C11---C12---C13   0.1 (4)
  C2---C3---C4---O1    179.8 (3)    C11---C12---C13---C8    −1.0 (4)
  C7---C3---C4---O1    0.8 (4)      C9---C8---C13---C12     1.1 (4)
  C2---C3---C4---C5    0.2 (4)      C7---C8---C13---C12     −178.4 (3)
  C7---C3---C4---C5    −178.9 (3)   N1---N2---C14---O2      0.0 (4)
  O1---C4---C5---C6    179.7 (3)    N1---N2---C14---C15     179.8 (2)
  C3---C4---C5---C6    −0.7 (4)     O2---C14---C15---C20    0.2 (4)
  C4---C5---C6---C1    0.2 (5)      N2---C14---C15---C20    −179.6 (2)
  C2---C1---C6---C5    0.7 (4)      O2---C14---C15---C16    −179.6 (3)
  Br1---C1---C6---C5   179.2 (2)    N2---C14---C15---C16    0.5 (4)
  N2---N1---C7---C3    180.0 (2)    C20---C15---C16---C17   −0.7 (5)
  N2---N1---C7---C8    0.4 (4)      C14---C15---C16---C17   179.1 (3)
  C2---C3---C7---N1    178.4 (2)    C15---C16---C17---C18   −1.6 (5)
  C4---C3---C7---N1    −2.5 (4)     C16---C17---C18---C19   2.9 (5)
  C2---C3---C7---C8    −2.0 (4)     C16---C17---C18---Cl1   −175.6 (2)
  C4---C3---C7---C8    177.1 (2)    C17---C18---C19---C20   −1.7 (5)
  N1---C7---C8---C9    79.9 (3)     Cl1---C18---C19---C20   176.7 (2)
  C3---C7---C8---C9    −99.7 (3)    C16---C15---C20---C19   1.9 (4)
  N1---C7---C8---C13   −100.6 (3)   C14---C15---C20---C19   −177.9 (3)
  C3---C7---C8---C13   79.9 (3)     C18---C19---C20---C15   −0.7 (5)
  -------------------- ------------ ----------------------- ------------

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

  --------------- --------- --------- ----------- ---------------
  *D*---H···*A*   *D*---H   H···*A*   *D*···*A*   *D*---H···*A*
  O1---H1···N1    0.82      1.84      2.554 (3)   145
  --------------- --------- --------- ----------- ---------------

###### Hydrogen-bond geometry (Å, °)

  *D*---H⋯*A*   *D*---H   H⋯*A*   *D*⋯*A*     *D*---H⋯*A*
  ------------- --------- ------- ----------- -------------
  O1---H1⋯N1    0.82      1.84    2.554 (3)   145
