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

For related crystal structures, see: Sun *et al.* (2007*a* [@bb4],*b* [@bb5],*c* [@bb6]).

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

 {#sec2.1}

### Crystal data {#sec2.1.1}

C~24~H~21~N~3~O~2~*M* *~r~* = 383.44Triclinic,*a* = 7.6640 (12) Å*b* = 8.3593 (14) Å*c* = 16.731 (3) Åα = 77.396 (3)°β = 77.587 (2)°γ = 76.240 (3)°*V* = 1000.9 (3) Å^3^*Z* = 2Mo *K*α radiationμ = 0.08 mm^−1^*T* = 273 (2) K0.18 × 0.16 × 0.12 mm

### Data collection {#sec2.1.2}

Bruker SMART CCD area-detector diffractometerAbsorption correction: multi-scan (*SADABS*; Sheldrick, 1996[@bb2]) *T* ~min~ = 0.985, *T* ~max~ = 0.9905300 measured reflections3505 independent reflections2584 reflections with *I* \> 2σ(*I*)*R* ~int~ = 0.015

### Refinement {#sec2.1.3}

*R*\[*F* ^2^ \> 2σ(*F* ^2^)\] = 0.043*wR*(*F* ^2^) = 0.117*S* = 1.043505 reflections264 parametersH-atom parameters constrainedΔρ~max~ = 0.17 e Å^−3^Δρ~min~ = −0.18 e Å^−3^

 {#d5e367}

Data collection: *SMART* (Bruker, 1997[@bb1]); cell refinement: *SAINT* (Bruker, 1997[@bb1]); data reduction: *SAINT*; program(s) used to solve structure: *SHELXS97* (Sheldrick, 2008[@bb3]); program(s) used to refine structure: *SHELXL97* (Sheldrick, 2008[@bb3]); molecular graphics: *SHELXTL* (Sheldrick, 2008[@bb3]); software used to prepare material for publication: *SHELXTL*.

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

Crystal structure: contains datablocks global, I. DOI: [10.1107/S1600536808024409/fj2143sup1.cif](http://dx.doi.org/10.1107/S1600536808024409/fj2143sup1.cif)

Structure factors: contains datablocks I. DOI: [10.1107/S1600536808024409/fj2143Isup2.hkl](http://dx.doi.org/10.1107/S1600536808024409/fj2143Isup2.hkl)

Additional supplementary materials: [crystallographic information](http://scripts.iucr.org/cgi-bin/sendsupfiles?fj2143&file=fj2143sup0.html&mime=text/html); [3D view](http://scripts.iucr.org/cgi-bin/sendcif?fj2143sup1&Qmime=cif); [checkCIF report](http://scripts.iucr.org/cgi-bin/paper?fj2143&checkcif=yes)

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: [FJ2143](http://scripts.iucr.org/cgi-bin/sendsup?fj2143)).

This project was supported by the Foundation of Taishan University.

Comment
=======

Antipyrine (2,3-dimethyl-1-phenylpyrazol-5-one) and its derivatives have been long known for their wide spectrum of biological activities. As part of our ongoing studies of antipyrine derivatives, the title compound, (I), has been prepared and its crystal structure is reported here (Fig. 1).

The molecule adopts an E configuration with respect to the central C=N double bond (Fig. 1).The pyrazole ring (N1/N2/C7---C9), the C13---C18 phenyl ring and the imino group are almost coplanar which allows conjugation. But the C1---C6 phenyl ring is twisted with respect to the central pyrazole ring plane by 39.3 (2)°. In addition, the mean planes of the C13---C18 and C19---C24 phenyl rings make a dihedral angle of 79.8 (2)°. Therefore the molecule is not planar. The bond distances and angles agree with the corresponding values found in similar compounds (Sun *et al.*, 2007*a*,b,c).

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

A mixture of 4-aminoantipyrine (1 mmol) and 3-phenoxybenzaldehyde (1 mmol) in anhydrous ethanol (20 ml) was refluxed for 3 hr, and then cooled to room temperature. After cooling, the solvent was removed under reduced pressure and the solid residue was recrystallized from ethanol to yield the pure product(66% yield). m.p. 425--427 K. A single-crystal suitable for an X-ray structural analysis was obtained by slowly evaporating a ethanolic solution at room temperature.

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

All H atoms were initially located in a difference Fourier map. The methyl H atoms were then constrained to an ideal geometry with C---H distances of 0.96 Å and *U*~iso~(H) = 1.5*U*~eq~(C). All other H atoms were placed in geometrically idealized positions and constrained to ride on their parent atoms with C---H distances 0.93 Å and *U*~iso~(H) = 1.2*U*~eq~(C).

Figures
=======

![View of the molecule of (I) showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are shown as small spheres of arbitrary radii.](e-64-o1679-fig1){#Fap1}

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

  ----------------------- ---------------------------------------
  C~24~H~21~N~3~O~2~      *Z* = 2
  *M~r~* = 383.44         *F*~000~ = 404
  Triclinic, *P*1         *D*~x~ = 1.272 Mg m^−3^
  Hall symbol: -P 1       Mo *K*α radiation λ = 0.71073 Å
  *a* = 7.6640 (12) Å     Cell parameters from 1817 reflections
  *b* = 8.3593 (14) Å     θ = 2--25.1º
  *c* = 16.731 (3) Å      µ = 0.08 mm^−1^
  α = 77.396 (3)º         *T* = 273 (2) K
  β = 77.587 (2)º         Block, colorless
  γ = 76.240 (3)º         0.18 × 0.16 × 0.12 mm
  *V* = 1000.9 (3) Å^3^   
  ----------------------- ---------------------------------------

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

  ------------------------------------------------------------ --------------------------------------
  Bruker SMART CCD area-detector diffractometer                3505 independent reflections
  Radiation source: fine-focus sealed tube                     2584 reflections with *I* \> 2σ(*I*)
  Monochromator: graphite                                      *R*~int~ = 0.016
  *T* = 273(2) K                                               θ~max~ = 25.1º
  φ and ω scans                                                θ~min~ = 2.5º
  Absorption correction: multi-scan(SADABS; Sheldrick, 1996)   *h* = −9→9
  *T*~min~ = 0.985, *T*~max~ = 0.990                           *k* = −9→8
  5300 measured reflections                                    *l* = −19→19
  ------------------------------------------------------------ --------------------------------------

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

  ---------------------------------------------------------------- ---------------------------------------------------------------------------------------------------
  Refinement on *F*^2^                                             Secondary atom site location: difference Fourier map
  Least-squares matrix: full                                       Hydrogen site location: difference Fourier map
  *R*\[*F*^2^ \> 2σ(*F*^2^)\] = 0.043                              H-atom parameters constrained
  *wR*(*F*^2^) = 0.117                                               *w* = 1/\[σ^2^(*F*~o~^2^) + (0.0553*P*)^2^ + 0.1379*P*\] where *P* = (*F*~o~^2^ + 2*F*~c~^2^)/3
  *S* = 1.04                                                       (Δ/σ)~max~ = 0.001
  3505 reflections                                                 Δρ~max~ = 0.17 e Å^−3^
  264 parameters                                                   Δρ~min~ = −0.18 e Å^−3^
  Primary atom site location: structure-invariant direct methods   Extinction correction: none
  ---------------------------------------------------------------- ---------------------------------------------------------------------------------------------------

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~   
  O1     −0.09698 (15)   0.55049 (16)   1.14179 (8)    0.0559 (3)           
  O2     −0.41493 (16)   1.0621 (2)     0.79039 (8)    0.0727 (4)           
  N1     0.17090 (17)    0.46344 (17)   1.19591 (8)    0.0451 (4)           
  N2     0.34291 (17)    0.50949 (17)   1.17773 (9)    0.0436 (3)           
  N3     0.15472 (18)    0.75399 (18)   1.00126 (8)    0.0463 (4)           
  C1     0.1017 (2)      0.3971 (2)     1.27873 (10)   0.0436 (4)           
  C2     0.1611 (2)      0.4293 (2)     1.34520 (11)   0.0534 (5)           
  H2     0.2455          0.4978         1.3359         0.064\*              
  C3     0.0942 (3)      0.3590 (3)     1.42535 (12)   0.0644 (6)           
  H3     0.1348          0.3798         1.4699         0.077\*              
  C4     −0.0311 (3)     0.2590 (3)     1.43974 (13)   0.0696 (6)           
  H4     −0.0752         0.2118         1.4938         0.084\*              
  C5     −0.0915 (3)     0.2288 (3)     1.37361 (13)   0.0641 (5)           
  H5     −0.1778         0.1620         1.3833         0.077\*              
  C6     −0.0253 (2)     0.2967 (2)     1.29318 (11)   0.0507 (4)           
  H6     −0.0659         0.2749         1.2488         0.061\*              
  C7     0.0644 (2)      0.5536 (2)     1.13636 (10)   0.0430 (4)           
  C8     0.1860 (2)      0.6450 (2)     1.07513 (10)   0.0412 (4)           
  C9     0.3485 (2)      0.6120 (2)     1.10112 (10)   0.0431 (4)           
  C10    0.5167 (2)      0.6735 (3)     1.05804 (11)   0.0573 (5)           
  H10A   0.6070          0.5828         1.0386         0.086\*              
  H10B   0.5625          0.7175         1.0960         0.086\*              
  H10C   0.4894          0.7600         1.0117         0.086\*              
  C11    0.4972 (2)      0.3701 (2)     1.19262 (13)   0.0607 (5)           
  H11A   0.5038          0.2889         1.1588         0.091\*              
  H11B   0.4801          0.3187         1.2502         0.091\*              
  H11C   0.6084          0.4116         1.1786         0.091\*              
  C12    0.0019 (2)      0.7838 (2)     0.97743 (10)   0.0477 (4)           
  H12    −0.0906         0.7318         1.0099         0.057\*              
  C13    −0.0321 (2)     0.8980 (2)     0.90021 (10)   0.0442 (4)           
  C14    0.1005 (2)      0.9784 (2)     0.84859 (11)   0.0502 (4)           
  H14    0.2152          0.9607         0.8628         0.060\*              
  C15    0.0622 (2)      1.0844 (2)     0.77623 (12)   0.0548 (5)           
  H15    0.1519          1.1379         0.7420         0.066\*              
  C16    −0.1063 (2)     1.1126 (2)     0.75369 (11)   0.0493 (4)           
  H16    −0.1304         1.1832         0.7044         0.059\*              
  C17    −0.2385 (2)     1.0347 (2)     0.80524 (11)   0.0474 (4)           
  C18    −0.2022 (2)     0.9280 (2)     0.87751 (11)   0.0492 (4)           
  H18    −0.2927         0.8753         0.9115         0.059\*              
  C19    −0.4469 (2)     1.1295 (2)     0.71019 (11)   0.0482 (4)           
  C20    −0.3803 (3)     1.0387 (3)     0.64795 (13)   0.0618 (5)           
  H20    −0.3083         0.9324         0.6586         0.074\*              
  C21    −0.4186 (3)     1.1025 (3)     0.57065 (14)   0.0781 (7)           
  H21    −0.3719         1.0402         0.5283         0.094\*              
  C22    −0.5239 (3)     1.2556 (4)     0.55469 (15)   0.0885 (8)           
  H22    −0.5492         1.2985         0.5013         0.106\*              
  C23    −0.5939 (3)     1.3483 (3)     0.61630 (18)   0.0836 (7)           
  H23    −0.6673         1.4536         0.6049         0.100\*              
  C24    −0.5555 (3)     1.2854 (2)     0.69626 (14)   0.0621 (5)           
  H24    −0.6020         1.3472         0.7388         0.075\*              
  ------ --------------- -------------- -------------- -------------------- --

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

  ----- ------------- ------------- ------------- -------------- -------------- --------------
        *U*^11^       *U*^22^       *U*^33^       *U*^12^        *U*^13^        *U*^23^
  O1    0.0386 (7)    0.0680 (9)    0.0613 (8)    −0.0141 (6)    −0.0158 (6)    −0.0009 (6)
  O2    0.0417 (7)    0.1136 (12)   0.0539 (8)    −0.0163 (7)    −0.0152 (6)    0.0112 (8)
  N1    0.0369 (7)    0.0496 (9)    0.0479 (9)    −0.0084 (6)    −0.0113 (6)    −0.0030 (7)
  N2    0.0319 (7)    0.0491 (8)    0.0488 (8)    −0.0050 (6)    −0.0119 (6)    −0.0051 (7)
  N3    0.0424 (8)    0.0543 (9)    0.0427 (8)    −0.0071 (7)    −0.0114 (6)    −0.0085 (7)
  C1    0.0398 (9)    0.0379 (9)    0.0476 (10)   0.0016 (7)     −0.0093 (7)    −0.0046 (7)
  C2    0.0522 (10)   0.0498 (11)   0.0575 (12)   −0.0003 (9)    −0.0169 (9)    −0.0114 (9)
  C3    0.0641 (12)   0.0728 (14)   0.0502 (12)   0.0075 (11)    −0.0153 (10)   −0.0160 (10)
  C4    0.0636 (13)   0.0783 (15)   0.0484 (12)   0.0006 (12)    −0.0003 (10)   0.0024 (10)
  C5    0.0561 (11)   0.0622 (13)   0.0640 (14)   −0.0119 (10)   0.0010 (10)    −0.0012 (10)
  C6    0.0458 (10)   0.0500 (11)   0.0527 (11)   −0.0052 (8)    −0.0071 (8)    −0.0078 (8)
  C7    0.0376 (9)    0.0453 (10)   0.0469 (10)   −0.0037 (7)    −0.0125 (7)    −0.0097 (8)
  C8    0.0369 (8)    0.0476 (10)   0.0400 (9)    −0.0061 (7)    −0.0095 (7)    −0.0092 (7)
  C9    0.0386 (9)    0.0492 (10)   0.0419 (9)    −0.0071 (7)    −0.0074 (7)    −0.0103 (8)
  C10   0.0409 (10)   0.0769 (14)   0.0537 (11)   −0.0155 (9)    −0.0075 (8)    −0.0070 (10)
  C11   0.0441 (10)   0.0598 (12)   0.0742 (13)   0.0031 (9)     −0.0205 (9)    −0.0080 (10)
  C12   0.0426 (9)    0.0555 (11)   0.0445 (10)   −0.0105 (8)    −0.0102 (8)    −0.0044 (8)
  C13   0.0422 (9)    0.0477 (10)   0.0437 (10)   −0.0073 (8)    −0.0109 (7)    −0.0089 (8)
  C14   0.0398 (9)    0.0562 (11)   0.0568 (11)   −0.0123 (8)    −0.0131 (8)    −0.0070 (9)
  C15   0.0497 (10)   0.0565 (12)   0.0590 (12)   −0.0211 (9)    −0.0095 (9)    −0.0004 (9)
  C16   0.0508 (10)   0.0451 (10)   0.0497 (10)   −0.0113 (8)    −0.0128 (8)    0.0020 (8)
  C17   0.0378 (9)    0.0568 (11)   0.0470 (10)   −0.0085 (8)    −0.0112 (8)    −0.0050 (8)
  C18   0.0429 (9)    0.0589 (11)   0.0449 (10)   −0.0142 (8)    −0.0078 (8)    −0.0024 (8)
  C19   0.0363 (9)    0.0573 (11)   0.0488 (11)   −0.0105 (8)    −0.0137 (8)    0.0028 (8)
  C20   0.0598 (12)   0.0541 (12)   0.0644 (13)   −0.0029 (9)    −0.0083 (10)   −0.0070 (10)
  C21   0.0711 (14)   0.1030 (19)   0.0636 (15)   −0.0168 (14)   −0.0149 (12)   −0.0192 (13)
  C22   0.0640 (14)   0.129 (2)     0.0611 (15)   −0.0159 (15)   −0.0246 (12)   0.0161 (15)
  C23   0.0583 (13)   0.0630 (14)   0.108 (2)     0.0043 (11)    −0.0239 (13)   0.0230 (14)
  C24   0.0521 (11)   0.0516 (12)   0.0806 (15)   −0.0063 (9)    −0.0097 (10)   −0.0134 (10)
  ----- ------------- ------------- ------------- -------------- -------------- --------------

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

  ------------------- ------------- ------------------- -------------
  O1---C7             1.2264 (19)   C11---H11A          0.9600
  O2---C17            1.383 (2)     C11---H11B          0.9600
  O2---C19            1.387 (2)     C11---H11C          0.9600
  N1---C7             1.399 (2)     C12---C13           1.462 (2)
  N1---N2             1.4130 (18)   C12---H12           0.9300
  N1---C1             1.413 (2)     C13---C18           1.386 (2)
  N2---C9             1.376 (2)     C13---C14           1.387 (2)
  N2---C11            1.471 (2)     C14---C15           1.378 (2)
  N3---C12            1.269 (2)     C14---H14           0.9300
  N3---C8             1.395 (2)     C15---C16           1.376 (2)
  C1---C6             1.382 (2)     C15---H15           0.9300
  C1---C2             1.386 (2)     C16---C17           1.374 (2)
  C2---C3             1.382 (3)     C16---H16           0.9300
  C2---H2             0.9300        C17---C18           1.375 (2)
  C3---C4             1.369 (3)     C18---H18           0.9300
  C3---H3             0.9300        C19---C20           1.362 (3)
  C4---C5             1.379 (3)     C19---C24           1.371 (3)
  C4---H4             0.9300        C20---C21           1.353 (3)
  C5---C6             1.379 (3)     C20---H20           0.9300
  C5---H5             0.9300        C21---C22           1.346 (4)
  C6---H6             0.9300        C21---H21           0.9300
  C7---C8             1.445 (2)     C22---C23           1.366 (4)
  C8---C9             1.354 (2)     C22---H22           0.9300
  C9---C10            1.483 (2)     C23---C24           1.393 (3)
  C10---H10A          0.9600        C23---H23           0.9300
  C10---H10B          0.9600        C24---H24           0.9300
  C10---H10C          0.9600                            
                                                        
  C17---O2---C19      118.13 (13)   H11A---C11---H11B   109.5
  C7---N1---N2        110.26 (13)   N2---C11---H11C     109.5
  C7---N1---C1        125.01 (13)   H11A---C11---H11C   109.5
  N2---N1---C1        119.24 (13)   H11B---C11---H11C   109.5
  C9---N2---N1        105.45 (12)   N3---C12---C13      121.58 (17)
  C9---N2---C11       119.28 (14)   N3---C12---H12      119.2
  N1---N2---C11       114.71 (14)   C13---C12---H12     119.2
  C12---N3---C8       121.20 (15)   C18---C13---C14     118.58 (16)
  C6---C1---C2        119.78 (17)   C18---C13---C12     119.30 (16)
  C6---C1---N1        119.10 (15)   C14---C13---C12     122.11 (15)
  C2---C1---N1        121.11 (16)   C15---C14---C13     120.02 (16)
  C3---C2---C1        119.65 (19)   C15---C14---H14     120.0
  C3---C2---H2        120.2         C13---C14---H14     120.0
  C1---C2---H2        120.2         C16---C15---C14     121.13 (17)
  C4---C3---C2        120.64 (19)   C16---C15---H15     119.4
  C4---C3---H3        119.7         C14---C15---H15     119.4
  C2---C3---H3        119.7         C17---C16---C15     118.93 (17)
  C3---C4---C5        119.6 (2)     C17---C16---H16     120.5
  C3---C4---H4        120.2         C15---C16---H16     120.5
  C5---C4---H4        120.2         C16---C17---C18     120.61 (16)
  C6---C5---C4        120.6 (2)     C16---C17---O2      123.25 (16)
  C6---C5---H5        119.7         C18---C17---O2      116.10 (16)
  C4---C5---H5        119.7         C17---C18---C13     120.72 (17)
  C5---C6---C1        119.70 (18)   C17---C18---H18     119.6
  C5---C6---H6        120.1         C13---C18---H18     119.6
  C1---C6---H6        120.1         C20---C19---C24     120.94 (18)
  O1---C7---N1        123.73 (16)   C20---C19---O2      120.53 (17)
  O1---C7---C8        131.93 (16)   C24---C19---O2      118.42 (17)
  N1---C7---C8        104.32 (14)   C21---C20---C19     120.2 (2)
  C9---C8---N3        121.71 (15)   C21---C20---H20     119.9
  C9---C8---C7        108.38 (15)   C19---C20---H20     119.9
  N3---C8---C7        129.89 (14)   C22---C21---C20     120.4 (2)
  C8---C9---N2        111.07 (15)   C22---C21---H21     119.8
  C8---C9---C10       128.06 (16)   C20---C21---H21     119.8
  N2---C9---C10       120.86 (14)   C21---C22---C23     120.5 (2)
  C9---C10---H10A     109.5         C21---C22---H22     119.8
  C9---C10---H10B     109.5         C23---C22---H22     119.8
  H10A---C10---H10B   109.5         C22---C23---C24     120.1 (2)
  C9---C10---H10C     109.5         C22---C23---H23     120.0
  H10A---C10---H10C   109.5         C24---C23---H23     120.0
  H10B---C10---H10C   109.5         C19---C24---C23     117.9 (2)
  N2---C11---H11A     109.5         C19---C24---H24     121.1
  N2---C11---H11B     109.5         C23---C24---H24     121.1
  ------------------- ------------- ------------------- -------------
