Crystal structure of the ethyl 2,4-dihy­droxy-6-methyl­benzoate from Illicium difengpi K.I.B et K.I.M.

The title compound, C₁₀H₁₂O₄, was isolated from Illicium difengpi K.I.B et K.I.M. An intra­molecular O—H...O hydrogen bond stabilizes the mol­ecular conformation. In the crystal, the compound forms offset slanted stacks of alternating inversion-related mol­ecules along the a axis direction. Inter­molecular O—H...O hydrogen bonds link the mol­ecules into double strands parallel to the [101] direction.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.057
• wR factor = 0.172
• Data-to-parameter ratio = 15.5

checkCIF/PLATON results

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Alert level G
PLAT002_ALERT_2_G Number of Distance or Angle Restraints on AtSite          4 Note
PLAT012_ALERT_1_G N.O.K.   _shelx_res_checksum Found in CIF ......     Please Check
PLAT072_ALERT_2_G SHELXL First  Parameter in WGHT  Unusually Large       0.10 Report
PLAT172_ALERT_4_G The CIF-Embedded .res File Contains DFIX Records          1 Report
PLAT199_ALERT_1_G Reported _cell_measurement_temperature ..... (K)        293 Check
PLAT200_ALERT_1_G Reported   _diffrn_ambient_temperature ..... (K)        293 Check
PLAT860_ALERT_3_G Number of Least-Squares Restraints .............          2 Note
PLAT933_ALERT_2_G Number of OMIT Records in Embedded .res File ...          1 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
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Computing details

Data collection: SMART (Bruker, 1997); cell refinement: SMART (Bruker, 1997); data reduction: SAINT-Plus (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2016 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008) and publCIF (Westrip, 2010); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and publCIF (Westrip, 2010).

Ethyl 2,4-dihydroxy-6-methylbenzoate

Crystal data

C10H12O4	F(000) = 416
Mr = 196.20	Dx = 1.348 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 7.818 (3) Å	Cell parameters from 878 reflections
b = 17.017 (6) Å	θ = 2.4–26.4°
c = 8.189 (3) Å	µ = 0.10 mm^−1
β = 117.459 (4)°	T = 293 K
V = 966.7 (6) Å^3	Sheet, colorless
Z = 4	0.15 × 0.13 × 0.08 mm

Data collection

Bruker SMART APEX CCD area-detector diffractometer	1390 reflections with I > 2σ(I)
phi and ω scans	Rint = 0.037
Absorption correction: multi-scan (SAINT-Plus; Bruker, 1999)	θmax = 27.5°, θmin = 2.4°
Tmin = 0.405, Tmax = 0.968	h = −5→10
4542 measured reflections	k = −21→22
2097 independent reflections	l = −10→8

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)] = 0.057	Hydrogen site location: mixed
wR(F^2) = 0.172	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.1019P)^2] where P = (Fo^2 + 2Fc^2)/3
2097 reflections	(Δ/σ)max < 0.001
135 parameters	Δρmax = 0.45 e Å^−3
2 restraints	Δρmin = −0.23 e Å^−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.

Refinement. The positions of hydroxyl H atoms attached to O3 and O4 were refined. All other H atoms were positioned geometrically and treated as riding atoms: C—H = 0.93–0.97 Å. U_iso(H) were set to 1.5U_eq(C/O) for CH₃ and OH, and to 1.2U_eq(C) for CH₂ and aromatic C—H.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	−0.0021 (2)	0.46363 (7)	−0.27773 (18)	0.0663 (5)
O2	0.11562 (18)	0.57656 (6)	−0.13811 (16)	0.0529 (4)
O3	0.1367 (2)	0.33529 (7)	−0.13142 (19)	0.0679 (5)
H3	0.050 (4)	0.3664 (16)	−0.216 (3)	0.102*
O4	0.6778 (2)	0.32885 (8)	0.44828 (18)	0.0718 (5)
H4	0.648 (4)	0.2753 (16)	0.410 (4)	0.108*
C1	0.2660 (2)	0.45967 (8)	0.0181 (2)	0.0420 (4)
C2	0.2682 (2)	0.37634 (9)	0.0131 (2)	0.0484 (4)
C3	0.4047 (3)	0.33288 (9)	0.1552 (3)	0.0551 (5)
H3A	0.403637	0.278312	0.148712	0.066*
C4	0.5412 (3)	0.37051 (10)	0.3052 (2)	0.0524 (5)
C5	0.5453 (3)	0.45134 (10)	0.3168 (2)	0.0525 (5)
H5	0.640522	0.475644	0.420632	0.063*
C6	0.4098 (2)	0.49723 (9)	0.1763 (2)	0.0450 (4)
C7	0.1165 (2)	0.49885 (9)	−0.1435 (2)	0.0450 (4)
C8	−0.0274 (3)	0.61634 (11)	−0.3005 (3)	0.0612 (5)
H8A	−0.156271	0.600967	−0.324130	0.073*
H8B	−0.010341	0.602890	−0.407205	0.073*
C9	0.0009 (4)	0.70282 (12)	−0.2630 (3)	0.0802 (7)
H9A	−0.015784	0.715282	−0.156911	0.120*
H9B	−0.091898	0.731300	−0.367576	0.120*
H9C	0.128638	0.717279	−0.240524	0.120*
C10	0.4251 (3)	0.58478 (9)	0.2029 (3)	0.0592 (5)
H10A	0.535726	0.597063	0.317280	0.089*
H10B	0.310970	0.604287	0.205170	0.089*
H10C	0.438365	0.608915	0.103419	0.089*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0702 (9)	0.0471 (7)	0.0545 (8)	−0.0021 (6)	0.0056 (7)	−0.0024 (5)
O2	0.0591 (8)	0.0349 (6)	0.0567 (8)	0.0057 (5)	0.0198 (6)	0.0033 (5)
O3	0.0783 (10)	0.0327 (6)	0.0659 (9)	−0.0050 (6)	0.0105 (7)	−0.0064 (5)
O4	0.0743 (10)	0.0545 (8)	0.0646 (9)	0.0156 (7)	0.0131 (8)	0.0103 (6)
C1	0.0470 (9)	0.0329 (8)	0.0473 (9)	−0.0001 (6)	0.0228 (8)	−0.0009 (6)
C2	0.0547 (10)	0.0351 (8)	0.0517 (10)	−0.0036 (7)	0.0214 (8)	−0.0036 (7)
C3	0.0657 (12)	0.0326 (8)	0.0659 (11)	0.0043 (8)	0.0294 (10)	0.0027 (8)
C4	0.0542 (10)	0.0455 (9)	0.0558 (10)	0.0095 (8)	0.0238 (9)	0.0080 (8)
C5	0.0501 (10)	0.0517 (10)	0.0479 (10)	−0.0036 (7)	0.0159 (8)	−0.0053 (7)
C6	0.0497 (9)	0.0377 (8)	0.0484 (9)	−0.0032 (7)	0.0234 (8)	−0.0029 (7)
C7	0.0496 (9)	0.0357 (8)	0.0485 (9)	−0.0018 (7)	0.0217 (8)	−0.0015 (7)
C8	0.0674 (12)	0.0505 (10)	0.0580 (11)	0.0125 (9)	0.0223 (10)	0.0125 (8)
C9	0.0965 (17)	0.0464 (11)	0.0998 (17)	0.0137 (10)	0.0471 (14)	0.0177 (10)
C10	0.0657 (12)	0.0390 (9)	0.0612 (11)	−0.0087 (8)	0.0192 (10)	−0.0093 (8)

Geometric parameters (Å, º)

O1—C7	1.220 (2)	C4—C5	1.378 (3)
O2—C7	1.323 (2)	C5—C6	1.390 (2)
O2—C8	1.451 (2)	C5—H5	0.9300
O3—C2	1.3502 (19)	C6—C10	1.502 (2)
O3—H3	0.89 (2)	C8—C9	1.499 (3)
O4—C4	1.365 (2)	C8—H8A	0.9700
O4—H4	0.96 (3)	C8—H8B	0.9700
C1—C6	1.417 (2)	C9—H9A	0.9600
C1—C2	1.419 (2)	C9—H9B	0.9600
C1—C7	1.461 (2)	C9—H9C	0.9600
C2—C3	1.377 (2)	C10—H10A	0.9600
C3—C4	1.359 (2)	C10—H10B	0.9600
C3—H3A	0.9300	C10—H10C	0.9600
C7—O2—C8	116.70 (13)	O1—C7—O2	120.51 (15)
C2—O3—H3	112.1 (18)	O1—C7—C1	123.39 (15)
C4—O4—H4	103.7 (17)	O2—C7—C1	116.10 (13)
C6—C1—C2	117.54 (14)	O2—C8—C9	106.95 (15)
C6—C1—C7	126.02 (14)	O2—C8—H8A	110.3
C2—C1—C7	116.42 (14)	C9—C8—H8A	110.3
O3—C2—C3	116.31 (14)	O2—C8—H8B	110.3
O3—C2—C1	121.87 (14)	C9—C8—H8B	110.3
C3—C2—C1	121.82 (15)	H8A—C8—H8B	108.6
C4—C3—C2	119.36 (15)	C8—C9—H9A	109.5
C4—C3—H3A	120.3	C8—C9—H9B	109.5
C2—C3—H3A	120.3	H9A—C9—H9B	109.5
C3—C4—O4	120.56 (15)	C8—C9—H9C	109.5
C3—C4—C5	121.07 (15)	H9A—C9—H9C	109.5
O4—C4—C5	118.36 (16)	H9B—C9—H9C	109.5
C4—C5—C6	121.27 (16)	C6—C10—H10A	109.5
C4—C5—H5	119.4	C6—C10—H10B	109.5
C6—C5—H5	119.4	H10A—C10—H10B	109.5
C5—C6—C1	118.93 (15)	C6—C10—H10C	109.5
C5—C6—C10	117.23 (15)	H10A—C10—H10C	109.5
C1—C6—C10	123.84 (14)	H10B—C10—H10C	109.5
C6—C1—C2—O3	179.79 (15)	C2—C1—C6—C5	0.4 (2)
C7—C1—C2—O3	−1.4 (2)	C7—C1—C6—C5	−178.29 (16)
C6—C1—C2—C3	−0.3 (2)	C2—C1—C6—C10	−179.25 (15)
C7—C1—C2—C3	178.47 (16)	C7—C1—C6—C10	2.1 (3)
O3—C2—C3—C4	−179.87 (17)	C8—O2—C7—O1	−2.1 (2)
C1—C2—C3—C4	0.3 (3)	C8—O2—C7—C1	177.74 (14)
C2—C3—C4—O4	179.75 (17)	C6—C1—C7—O1	178.68 (16)
C2—C3—C4—C5	−0.2 (3)	C2—C1—C7—O1	0.0 (2)
C3—C4—C5—C6	0.3 (3)	C6—C1—C7—O2	−1.1 (2)
O4—C4—C5—C6	−179.68 (16)	C2—C1—C7—O2	−179.83 (14)
C4—C5—C6—C1	−0.4 (2)	C7—O2—C8—C9	−179.38 (14)
C4—C5—C6—C10	179.29 (16)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···O1	0.89 (2)	1.72 (3)	2.4868 (18)	143 (3)
O4—H4···O3^i	0.96 (3)	1.91 (3)	2.853 (2)	169 (3)
C3—H3A···O4^ii	0.93	2.54	3.290 (2)	138

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