2,6-Di­methyl-4H-1-benzo­pyran-4-one

The title compound, C₁₁H₁₀O₂, belongs to the class of 4-benzopyrones (also known as chromen-4-ones) with potentially diverse pharmacological activities. It was synthesized by acyl­ation of 2-hydroxy-4-methyl­aceto­phenone with ethyl acetate in the presence of sodium hydride and subsequent cyclization by hydro­chloric acid. All non-H atoms of the substituted bicyclic mol­ecule are coplanar within 0.03 Å. C—H...O interactions [C...O = 3.272 (5) Å] link neighbouring mol­ecules related by the 2₁ axis.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.054
• wR factor = 0.184
• Data-to-parameter ratio = 12.9

checkCIF/PLATON results

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Alert level C
PLAT380_ALERT_4_C Incorrectly Oriented X(sp2)-Methyl Moiety ......         C1
PLAT380_ALERT_4_C Incorrectly Oriented X(sp2)-Methyl Moiety ......        C10

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

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

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Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

2,6-Dimethyl-4H-1-benzopyran-4-one

Crystal data

C11H10O2	F(000) = 368
Mr = 174.19	Dx = 1.312 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 7949 reflections
a = 5.4595 (5) Å	θ = 2.3–29.4°
b = 10.1947 (14) Å	µ = 0.09 mm^−1
c = 15.8862 (15) Å	T = 293 K
β = 93.979 (8)°	Prism, colourless
V = 882.06 (17) Å^3	0.60 × 0.45 × 0.30 mm
Z = 4

Data collection

Stoe IPDS-2 diffractometer	1740 independent reflections
Radiation source: fine-focus sealed tube	1328 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.088
Detector resolution: 6.67 pixels mm^-1	θmax = 26.0°, θmin = 2.4°
rotation method scans	h = −6→6
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −12→12
Tmin = 0.942, Tmax = 0.982	l = −19→19
6705 measured reflections

Refinement

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)] = 0.054	H atoms treated by a mixture of independent and constrained refinement
wR(F^2) = 0.184	w = 1/[σ^2(Fo^2) + (0.1083P)^2 + 0.0774P] where P = (Fo^2 + 2Fc^2)/3
S = 1.11	(Δ/σ)max < 0.001
1740 reflections	Δρmax = 0.35 e Å^−3
135 parameters	Δρmin = −0.24 e Å^−3
6 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.093 (16)

Special details

Experimental. Melting points were measured with a capillary melting point apparatus (Buchi). The ¹H NMR spectra were recorded with VARIAN Mercury 400 F T-NMR spectrophotometer, d scale (p.p.m.) from TMS. Mass spectra were measured with Waters Micromass ZQ by using ES(+) method.

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
O1	−0.2543 (2)	0.52505 (13)	0.10857 (8)	0.0511 (4)
O2	0.3617 (3)	0.68843 (16)	0.22357 (9)	0.0697 (5)
C1	−0.3200 (4)	0.3829 (2)	0.22073 (15)	0.0607 (6)
H1A	−0.4548	0.3637	0.1806	0.091*
H1B	−0.3821	0.4130	0.2724	0.091*
H1C	−0.2240	0.3050	0.2315	0.091*
C2	−0.1652 (3)	0.48550 (19)	0.18658 (11)	0.0485 (5)
C3	0.0386 (3)	0.5368 (2)	0.22472 (12)	0.0511 (5)
H3	0.085 (4)	0.507 (2)	0.2785 (15)	0.068 (6)*
C4	0.1773 (3)	0.63785 (19)	0.18847 (11)	0.0485 (5)
C4A	0.0809 (3)	0.67825 (17)	0.10306 (10)	0.0444 (5)
C5	0.1959 (4)	0.77291 (19)	0.05643 (12)	0.0513 (5)
H5	0.335 (5)	0.811 (2)	0.0815 (15)	0.067 (7)*
C6	0.1052 (4)	0.80816 (19)	−0.02364 (12)	0.0533 (5)
C7	−0.1065 (4)	0.7456 (2)	−0.05750 (12)	0.0571 (6)
H7	−0.171 (5)	0.773 (2)	−0.1161 (17)	0.076 (7)*
C8	−0.2242 (4)	0.6526 (2)	−0.01345 (12)	0.0550 (5)
H8	−0.373 (4)	0.609 (2)	−0.0343 (15)	0.064 (6)*
C9	−0.1297 (3)	0.61906 (18)	0.06751 (11)	0.0451 (5)
C10	0.2281 (5)	0.9122 (2)	−0.07349 (15)	0.0726 (7)
H10A	0.1391	0.9232	−0.1273	0.109*
H10B	0.3936	0.8860	−0.0818	0.109*
H10C	0.2299	0.9936	−0.0431	0.109*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0468 (7)	0.0604 (8)	0.0450 (8)	−0.0031 (6)	−0.0054 (5)	−0.0018 (6)
O2	0.0646 (9)	0.0890 (12)	0.0526 (9)	−0.0150 (8)	−0.0163 (7)	−0.0062 (7)
C1	0.0567 (11)	0.0621 (12)	0.0636 (13)	0.0009 (9)	0.0070 (9)	0.0046 (10)
C2	0.0485 (10)	0.0529 (10)	0.0439 (10)	0.0103 (8)	0.0015 (7)	−0.0033 (8)
C3	0.0512 (11)	0.0620 (12)	0.0392 (10)	0.0070 (8)	−0.0028 (8)	−0.0013 (8)
C4	0.0467 (10)	0.0589 (11)	0.0387 (9)	0.0040 (8)	−0.0048 (7)	−0.0102 (8)
C4A	0.0463 (10)	0.0497 (10)	0.0367 (9)	0.0053 (7)	0.0000 (7)	−0.0100 (7)
C5	0.0519 (11)	0.0553 (11)	0.0464 (10)	−0.0002 (9)	0.0018 (8)	−0.0098 (8)
C6	0.0599 (12)	0.0558 (11)	0.0448 (10)	0.0089 (9)	0.0096 (8)	−0.0035 (8)
C7	0.0611 (12)	0.0680 (13)	0.0414 (10)	0.0121 (10)	−0.0016 (8)	−0.0012 (9)
C8	0.0508 (11)	0.0694 (13)	0.0434 (10)	0.0011 (9)	−0.0084 (8)	−0.0045 (9)
C9	0.0434 (9)	0.0520 (10)	0.0393 (9)	0.0049 (7)	−0.0012 (7)	−0.0071 (7)
C10	0.0918 (17)	0.0669 (14)	0.0604 (13)	0.0009 (12)	0.0145 (12)	0.0069 (10)

Geometric parameters (Å, º)

O1—C2	1.361 (2)	C8—H8	0.96 (2)
O1—C9	1.367 (2)	C7—C6	1.395 (3)
O2—C4	1.230 (2)	C7—H7	1.01 (3)
C2—C3	1.336 (3)	C6—C5	1.380 (3)
C2—C1	1.472 (3)	C6—C10	1.509 (3)
C3—C4	1.424 (3)	C5—H5	0.92 (3)
C3—H3	0.93 (2)	C1—H1A	0.9600
C4—C4A	1.479 (2)	C1—H1B	0.9600
C4A—C9	1.384 (3)	C1—H1C	0.9600
C4A—C5	1.392 (3)	C10—H10A	0.9600
C9—C8	1.395 (3)	C10—H10B	0.9600
C8—C7	1.365 (3)	C10—H10C	0.9600
C2—O1—C9	118.97 (14)	C8—C7—H7	121.2 (14)
C3—C2—O1	122.06 (18)	C6—C7—H7	117.0 (14)
C3—C2—C1	126.33 (18)	C5—C6—C7	118.08 (19)
O1—C2—C1	111.61 (16)	C5—C6—C10	121.5 (2)
C2—C3—C4	123.32 (18)	C7—C6—C10	120.39 (19)
C2—C3—H3	117.2 (15)	C6—C5—C4A	121.65 (19)
C4—C3—H3	119.4 (15)	C6—C5—H5	121.4 (15)
O2—C4—C3	124.17 (17)	C4A—C5—H5	117.0 (15)
O2—C4—C4A	121.80 (19)	C2—C1—H1A	109.5
C3—C4—C4A	114.03 (16)	C2—C1—H1B	109.5
C9—C4A—C5	118.53 (17)	H1A—C1—H1B	109.5
C9—C4A—C4	119.04 (17)	C2—C1—H1C	109.5
C5—C4A—C4	122.42 (17)	H1A—C1—H1C	109.5
O1—C9—C4A	122.53 (16)	H1B—C1—H1C	109.5
O1—C9—C8	116.61 (16)	C6—C10—H10A	109.5
C4A—C9—C8	120.86 (18)	C6—C10—H10B	109.5
C7—C8—C9	119.09 (18)	H10A—C10—H10B	109.5
C7—C8—H8	124.2 (14)	C6—C10—H10C	109.5
C9—C8—H8	116.7 (14)	H10A—C10—H10C	109.5
C8—C7—C6	121.79 (18)	H10B—C10—H10C	109.5
C9—O1—C2—C3	0.8 (3)	C4—C4A—C9—O1	0.6 (3)
C9—O1—C2—C1	−179.22 (14)	C5—C4A—C9—C8	0.4 (3)
O1—C2—C3—C4	1.2 (3)	C4—C4A—C9—C8	−178.86 (16)
C1—C2—C3—C4	−178.82 (17)	O1—C9—C8—C7	−179.71 (16)
C2—C3—C4—O2	178.10 (19)	C4A—C9—C8—C7	−0.2 (3)
C2—C3—C4—C4A	−2.1 (3)	C9—C8—C7—C6	−0.2 (3)
O2—C4—C4A—C9	−178.97 (17)	C8—C7—C6—C5	0.5 (3)
C3—C4—C4A—C9	1.2 (2)	C8—C7—C6—C10	−178.89 (18)
O2—C4—C4A—C5	1.8 (3)	C7—C6—C5—C4A	−0.3 (3)
C3—C4—C4A—C5	−178.03 (16)	C10—C6—C5—C4A	179.07 (17)
C2—O1—C9—C4A	−1.6 (2)	C9—C4A—C5—C6	−0.2 (3)
C2—O1—C9—C8	177.81 (16)	C4—C4A—C5—C6	179.11 (17)
C5—C4A—C9—O1	179.86 (15)