Ethyl 3-(10-chloro­anthracen­yl)-5-(1-phenyl-2-hydroxy­ethen­yl)isoxazole-4-carboxyl­ate: an enol produced by Dess–Martin oxidation

The title compound, C₂₈H₂₀ClNO₄, is a very stable enol produced by a Dess–Martin oxidation, not the expected ketone. The enol form is stabilized by intra­molecular hydrogen bonding and the mol­ecules associate into dimers via weak C—H...N hydrogen bonding.

Key indicators

• Single-crystal X-ray study
• T = 87 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.035
• wR factor = 0.095
• Data-to-parameter ratio = 12.7

checkCIF/PLATON results

No syntax errors found



Alert level B
PLAT230_ALERT_2_B Hirshfeld Test Diff for    C27    -   C28     ..       9.93 su

Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       2.78 Ratio
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.04 Ratio
PLAT480_ALERT_4_C Long H...A H-Bond Reported H19    ..  N1      ..       2.68 Ang.

   0 ALERT level A = In general: serious problem
   1 ALERT level B = Potentially serious problem
   4 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: XS in SHELXTL (Bruker, 2001); program(s) used to refine structure: XL in SHELXTL; molecular graphics: XP in SHELXTL; software used to prepare material for publication: XCIF in SHELXTL.

Ethyl 3-(10-chloroanthracenyl)-5-(1-phenyl-2-hydroxyethenyl)isoxazole-4-carboxylate

Crystal data

C28H20ClNO4	F(000) = 976
Mr = 469.90	Dx = 1.422 Mg m^−3
Monoclinic, P21/n	Melting point = 192.5–193.0 K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 10.6621 (12) Å	Cell parameters from 7425 reflections
b = 15.5874 (17) Å	θ = 2.3–30.0°
c = 13.2180 (15) Å	µ = 0.21 mm^−1
β = 92.069 (2)°	T = 87 K
V = 2195.3 (4) Å^3	Parellelepiped, pale yellow
Z = 4	0.44 × 0.41 × 0.19 mm

Data collection

Bruker/Siemens SMART APEX diffractometer	3975 independent reflections
Radiation source: normal-focus sealed tube	3724 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
Detector resolution: 8.3 pixels mm^-1	θmax = 25.3°, θmin = 2.0°
ω scans	h = −12→12
Absorption correction: multi-scan (SADABS; Bruker, 2001)	k = −18→18
Tmin = 0.913, Tmax = 0.961	l = −15→15
32656 measured reflections

Refinement

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.095	H atoms treated by a mixture of independent and constrained refinement
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0505P)^2 + 1.2473P] where P = (Fo^2 + 2Fc^2)/3
3975 reflections	(Δ/σ)max = 0.001
312 parameters	Δρmax = 0.29 e Å^−3
0 restraints	Δρmin = −0.44 e Å^−3

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 F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² 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 (Ų)

	x	y	z	Uiso*/Ueq
C1	0.86779 (14)	0.14531 (10)	0.71931 (12)	0.0248 (3)
C2	0.87652 (13)	0.22790 (10)	0.75979 (11)	0.0230 (3)
C3	0.92284 (14)	0.24570 (11)	0.86064 (12)	0.0289 (4)
H3	0.9460	0.1995	0.9043	0.035*
C4	0.93422 (16)	0.32753 (12)	0.89475 (12)	0.0327 (4)
H4	0.9662	0.3379	0.9617	0.039*
C5	0.89906 (15)	0.39762 (12)	0.83182 (12)	0.0305 (4)
H5	0.9090	0.4546	0.8563	0.037*
C6	0.85105 (14)	0.38383 (10)	0.73635 (11)	0.0243 (3)
H6	0.8251	0.4314	0.6958	0.029*
C7	0.83898 (13)	0.29898 (10)	0.69609 (11)	0.0209 (3)
C8	0.79450 (13)	0.28320 (9)	0.59629 (11)	0.0191 (3)
C9	0.78998 (13)	0.20011 (9)	0.55620 (11)	0.0211 (3)
C10	0.75121 (14)	0.18369 (10)	0.45362 (12)	0.0249 (3)
H10	0.7246	0.2301	0.4115	0.030*
C11	0.75157 (16)	0.10299 (10)	0.41505 (13)	0.0318 (4)
H11	0.7256	0.0935	0.3465	0.038*
C12	0.79061 (18)	0.03282 (11)	0.47677 (14)	0.0365 (4)
H12	0.7910	−0.0234	0.4490	0.044*
C13	0.82733 (16)	0.04513 (10)	0.57488 (14)	0.0319 (4)
H13	0.8527	−0.0027	0.6151	0.038*
C14	0.82862 (14)	0.12865 (10)	0.61877 (12)	0.0245 (3)
C15	0.75601 (13)	0.35870 (9)	0.53314 (10)	0.0179 (3)
C16	0.83039 (13)	0.41102 (9)	0.46936 (10)	0.0174 (3)
C17	0.75277 (13)	0.47873 (9)	0.44322 (10)	0.0177 (3)
C18	0.76851 (13)	0.55975 (9)	0.38909 (10)	0.0184 (3)
C19	0.67292 (13)	0.61599 (9)	0.37961 (10)	0.0197 (3)
H19	0.5936	0.5955	0.3994	0.024*
C20	0.67500 (14)	0.70446 (9)	0.34287 (10)	0.0197 (3)
C21	0.56174 (14)	0.75024 (10)	0.34302 (11)	0.0223 (3)
H21	0.4871	0.7215	0.3609	0.027*
C22	0.55641 (15)	0.83638 (10)	0.31772 (11)	0.0242 (3)
H22	0.4787	0.8662	0.3184	0.029*
C23	0.66485 (15)	0.87916 (9)	0.29132 (11)	0.0242 (3)
H23	0.6620	0.9385	0.2751	0.029*
C24	0.77734 (15)	0.83449 (10)	0.28885 (12)	0.0257 (3)
H24	0.8512	0.8634	0.2697	0.031*
C25	0.78330 (14)	0.74817 (9)	0.31397 (11)	0.0233 (3)
H25	0.8609	0.7185	0.3116	0.028*
C26	0.95787 (13)	0.39255 (9)	0.43653 (10)	0.0176 (3)
C27	1.10866 (14)	0.28141 (10)	0.41952 (12)	0.0242 (3)
H27A	1.1774	0.2992	0.4673	0.029*
H27B	1.1257	0.3041	0.3514	0.029*
C28	1.09598 (19)	0.18542 (13)	0.41719 (18)	0.0484 (5)
H28A	1.0774	0.1645	0.4849	0.073*
H28B	1.1747	0.1599	0.3957	0.073*
H28C	1.0276	0.1693	0.3694	0.073*
Cl1	0.90911 (4)	0.05874 (3)	0.79712 (3)	0.03525 (13)
N1	0.64362 (11)	0.39039 (8)	0.54212 (9)	0.0207 (3)
O1	0.64034 (9)	0.46639 (6)	0.48395 (7)	0.0195 (2)
O2	0.88388 (10)	0.57721 (7)	0.35447 (8)	0.0231 (2)
H2A	0.935 (2)	0.5367 (13)	0.3698 (15)	0.038 (5)*
O3	1.02681 (9)	0.44437 (6)	0.39678 (7)	0.0203 (2)
O4	0.98774 (9)	0.31151 (6)	0.45328 (8)	0.0216 (2)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0198 (7)	0.0261 (8)	0.0284 (8)	−0.0019 (6)	−0.0016 (6)	0.0121 (6)
C2	0.0153 (7)	0.0310 (8)	0.0230 (7)	−0.0015 (6)	0.0030 (6)	0.0067 (6)
C3	0.0221 (7)	0.0425 (9)	0.0222 (8)	0.0004 (7)	0.0005 (6)	0.0079 (7)
C4	0.0284 (8)	0.0490 (11)	0.0206 (8)	−0.0014 (7)	−0.0011 (6)	−0.0011 (7)
C5	0.0294 (8)	0.0367 (9)	0.0255 (8)	−0.0019 (7)	0.0033 (6)	−0.0053 (7)
C6	0.0220 (7)	0.0283 (8)	0.0228 (7)	0.0001 (6)	0.0043 (6)	0.0008 (6)
C7	0.0146 (7)	0.0266 (8)	0.0217 (7)	−0.0017 (6)	0.0038 (5)	0.0027 (6)
C8	0.0153 (7)	0.0213 (7)	0.0210 (7)	−0.0021 (5)	0.0025 (5)	0.0047 (6)
C9	0.0176 (7)	0.0199 (7)	0.0257 (8)	−0.0028 (5)	0.0009 (6)	0.0048 (6)
C10	0.0268 (8)	0.0208 (7)	0.0268 (8)	−0.0026 (6)	−0.0035 (6)	0.0042 (6)
C11	0.0392 (9)	0.0240 (8)	0.0318 (9)	−0.0046 (7)	−0.0072 (7)	−0.0010 (7)
C12	0.0461 (10)	0.0183 (8)	0.0446 (10)	−0.0035 (7)	−0.0076 (8)	−0.0009 (7)
C13	0.0353 (9)	0.0182 (8)	0.0417 (10)	−0.0022 (6)	−0.0067 (7)	0.0080 (7)
C14	0.0201 (7)	0.0224 (7)	0.0310 (8)	−0.0035 (6)	−0.0007 (6)	0.0072 (6)
C15	0.0197 (7)	0.0169 (7)	0.0170 (7)	−0.0026 (5)	−0.0001 (5)	−0.0014 (5)
C16	0.0202 (7)	0.0151 (7)	0.0169 (7)	−0.0025 (5)	−0.0008 (5)	−0.0010 (5)
C17	0.0191 (7)	0.0180 (7)	0.0160 (6)	−0.0027 (5)	0.0002 (5)	−0.0028 (5)
C18	0.0212 (7)	0.0168 (7)	0.0171 (7)	−0.0032 (5)	0.0011 (5)	−0.0016 (5)
C19	0.0203 (7)	0.0187 (7)	0.0201 (7)	−0.0034 (5)	0.0014 (5)	0.0000 (5)
C20	0.0248 (7)	0.0182 (7)	0.0161 (7)	−0.0013 (6)	−0.0007 (5)	−0.0003 (5)
C21	0.0243 (7)	0.0218 (7)	0.0207 (7)	−0.0012 (6)	0.0010 (6)	0.0026 (6)
C22	0.0287 (8)	0.0222 (7)	0.0215 (7)	0.0046 (6)	−0.0008 (6)	0.0018 (6)
C23	0.0369 (9)	0.0163 (7)	0.0192 (7)	−0.0011 (6)	−0.0029 (6)	0.0023 (6)
C24	0.0297 (8)	0.0215 (7)	0.0260 (8)	−0.0066 (6)	0.0007 (6)	0.0028 (6)
C25	0.0247 (8)	0.0207 (7)	0.0245 (7)	−0.0009 (6)	0.0010 (6)	0.0017 (6)
C26	0.0206 (7)	0.0170 (7)	0.0151 (6)	−0.0014 (5)	−0.0019 (5)	−0.0013 (5)
C27	0.0220 (7)	0.0228 (8)	0.0282 (8)	0.0045 (6)	0.0052 (6)	−0.0001 (6)
C28	0.0420 (11)	0.0364 (11)	0.0674 (14)	0.0056 (8)	0.0116 (10)	0.0006 (9)
Cl1	0.0362 (2)	0.0307 (2)	0.0381 (2)	−0.00373 (16)	−0.00901 (18)	0.01883 (17)
N1	0.0226 (6)	0.0169 (6)	0.0226 (6)	−0.0013 (5)	0.0021 (5)	0.0055 (5)
O1	0.0192 (5)	0.0167 (5)	0.0228 (5)	−0.0007 (4)	0.0029 (4)	0.0042 (4)
O2	0.0205 (5)	0.0185 (5)	0.0307 (6)	0.0005 (4)	0.0059 (4)	0.0047 (4)
O3	0.0188 (5)	0.0188 (5)	0.0234 (5)	−0.0024 (4)	0.0021 (4)	0.0008 (4)
O4	0.0218 (5)	0.0175 (5)	0.0259 (5)	0.0014 (4)	0.0050 (4)	0.0017 (4)

Geometric parameters (Å, º)

C1—C2	1.396 (2)	C16—C26	1.4701 (19)
C1—C14	1.403 (2)	C17—O1	1.3456 (17)
C1—Cl1	1.7436 (15)	C17—C18	1.4641 (19)
C2—C3	1.432 (2)	C18—C19	1.347 (2)
C2—C7	1.440 (2)	C18—O2	1.3555 (17)
C3—C4	1.357 (3)	C19—C20	1.4625 (19)
C3—H3	0.9500	C19—H19	0.9500
C4—C5	1.415 (2)	C20—C21	1.403 (2)
C4—H4	0.9500	C20—C25	1.406 (2)
C5—C6	1.362 (2)	C21—C22	1.384 (2)
C5—H5	0.9500	C21—H21	0.9500
C6—C7	1.430 (2)	C22—C23	1.390 (2)
C6—H6	0.9500	C22—H22	0.9500
C7—C8	1.407 (2)	C23—C24	1.388 (2)
C8—C9	1.400 (2)	C23—H23	0.9500
C8—C15	1.4918 (19)	C24—C25	1.387 (2)
C9—C10	1.426 (2)	C24—H24	0.9500
C9—C14	1.439 (2)	C25—H25	0.9500
C10—C11	1.357 (2)	C26—O3	1.2234 (17)
C10—H10	0.9500	C26—O4	1.3195 (17)
C11—C12	1.418 (2)	C27—O4	1.4571 (17)
C11—H11	0.9500	C27—C28	1.503 (2)
C12—C13	1.355 (3)	C27—H27A	0.9900
C12—H12	0.9500	C27—H27B	0.9900
C13—C14	1.425 (2)	C28—H28A	0.9800
C13—H13	0.9500	C28—H28B	0.9800
C15—N1	1.3055 (19)	C28—H28C	0.9800
C15—C16	1.4328 (19)	N1—O1	1.4120 (15)
C16—C17	1.378 (2)	O2—H2A	0.86 (2)
C2—C1—C14	123.18 (13)	C15—C16—C26	126.83 (13)
C2—C1—Cl1	118.41 (12)	O1—C17—C16	109.02 (12)
C14—C1—Cl1	118.41 (12)	O1—C17—C18	116.00 (12)
C1—C2—C3	123.47 (14)	C16—C17—C18	134.83 (13)
C1—C2—C7	118.18 (14)	C19—C18—O2	122.06 (13)
C3—C2—C7	118.33 (14)	C19—C18—C17	120.48 (13)
C4—C3—C2	121.02 (15)	O2—C18—C17	117.36 (12)
C4—C3—H3	119.5	C18—C19—C20	128.63 (13)
C2—C3—H3	119.5	C18—C19—H19	115.7
C3—C4—C5	120.78 (15)	C20—C19—H19	115.7
C3—C4—H4	119.6	C21—C20—C25	118.00 (13)
C5—C4—H4	119.6	C21—C20—C19	117.13 (13)
C6—C5—C4	120.37 (16)	C25—C20—C19	124.74 (13)
C6—C5—H5	119.8	C22—C21—C20	121.40 (14)
C4—C5—H5	119.8	C22—C21—H21	119.3
C5—C6—C7	121.12 (15)	C20—C21—H21	119.3
C5—C6—H6	119.4	C21—C22—C23	119.90 (14)
C7—C6—H6	119.4	C21—C22—H22	120.0
C8—C7—C6	122.24 (13)	C23—C22—H22	120.0
C8—C7—C2	119.40 (14)	C24—C23—C22	119.50 (14)
C6—C7—C2	118.35 (13)	C24—C23—H23	120.2
C9—C8—C7	121.50 (13)	C22—C23—H23	120.2
C9—C8—C15	120.87 (13)	C25—C24—C23	120.87 (14)
C7—C8—C15	117.60 (13)	C25—C24—H24	119.6
C8—C9—C10	122.06 (13)	C23—C24—H24	119.6
C8—C9—C14	119.57 (14)	C24—C25—C20	120.29 (14)
C10—C9—C14	118.34 (13)	C24—C25—H25	119.9
C11—C10—C9	121.24 (14)	C20—C25—H25	119.9
C11—C10—H10	119.4	O3—C26—O4	123.99 (13)
C9—C10—H10	119.4	O3—C26—C16	125.01 (13)
C10—C11—C12	120.24 (15)	O4—C26—C16	110.98 (12)
C10—C11—H11	119.9	O4—C27—C28	104.30 (13)
C12—C11—H11	119.9	O4—C27—H27A	110.9
C13—C12—C11	120.68 (16)	C28—C27—H27A	110.9
C13—C12—H12	119.7	O4—C27—H27B	110.9
C11—C12—H12	119.7	C28—C27—H27B	110.9
C12—C13—C14	121.15 (15)	H27A—C27—H27B	108.9
C12—C13—H13	119.4	C27—C28—H28A	109.5
C14—C13—H13	119.4	C27—C28—H28B	109.5
C1—C14—C13	123.56 (14)	H28A—C28—H28B	109.5
C1—C14—C9	118.07 (14)	C27—C28—H28C	109.5
C13—C14—C9	118.35 (14)	H28A—C28—H28C	109.5
N1—C15—C16	111.56 (12)	H28B—C28—H28C	109.5
N1—C15—C8	118.85 (12)	C15—N1—O1	105.83 (11)
C16—C15—C8	129.15 (12)	C17—O1—N1	109.45 (10)
C17—C16—C15	104.09 (12)	C18—O2—H2A	110.8 (14)
C17—C16—C26	129.01 (13)	C26—O4—C27	117.89 (11)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C19—H19···N1^i	0.95	2.68	3.5669 (19)	156
C21—H21···N1^i	0.95	2.60	3.4849 (19)	155
O2—H2A···O3	0.86 (2)	1.77 (2)	2.6193 (14)	173 (2)

Symmetry code: (i) −x+1, −y+1, −z+1.