2-(Carboxy­meth­yl)-4,6-dimethoxy­benzoic acid

The title compound, C₁₁H₁₂O₆, is a key inter­mediate for the synthesis of naturally occurring biologically active isocoumarin derivatives. In the crystal packing, mol­ecules are linked into a two-dimensional network structure via inter­molecular C—H...O hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 292 K
• Mean [sigma](C-C)= 0.002 Å
• R factor = 0.044
• wR factor = 0.125
• Data-to-parameter ratio = 14.7

checkCIF/PLATON results

No syntax errors found


No errors found in this datablock

---

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1999); software used to prepare material for publication: SHELXTL.

2-(Carboxymethyl)-4,6-dimethoxybenzoic acid

Crystal data

C11H12O6	Z = 2
Mr = 240.21	F(000) = 252
Triclinic, P1	Dx = 1.442 Mg m^−3
Hall symbol: -P 1	Melting point: 170 K
a = 7.2886 (10) Å	Mo Kα radiation, λ = 0.71073 Å
b = 7.9631 (11) Å	Cell parameters from 2688 reflections
c = 10.2758 (14) Å	θ = 2.7–28.2°
α = 105.937 (2)°	µ = 0.12 mm^−1
β = 103.444 (2)°	T = 292 K
γ = 93.211 (2)°	Block, light yellow
V = 553.17 (13) Å^3	0.24 × 0.20 × 0.20 mm

Data collection

Bruker SMART CCD area-detector diffractometer	2380 independent reflections
Radiation source: fine-focus sealed tube	2074 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.048
φ and ω scans	θmax = 27.0°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −9→9
Tmin = 0.966, Tmax = 0.977	k = −10→10
4782 measured reflections	l = −12→13

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.126	H atoms treated by a mixture of independent and constrained refinement
S = 1.08	w = 1/[σ^2(Fo^2) + (0.0658P)^2 + 0.0652P] where P = (Fo^2 + 2Fc^2)/3
2380 reflections	(Δ/σ)max < 0.001
162 parameters	Δρmax = 0.24 e Å^−3
2 restraints	Δρmin = −0.19 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	0.28940 (18)	0.75801 (16)	0.68898 (14)	0.0361 (3)
C2	0.10780 (19)	0.81130 (16)	0.68927 (13)	0.0364 (3)
C3	−0.02643 (18)	0.77948 (17)	0.55930 (14)	0.0368 (3)
C4	0.01674 (18)	0.69458 (18)	0.43471 (14)	0.0382 (3)
H4	−0.0734	0.6736	0.3496	0.046*
C5	0.19461 (19)	0.64154 (17)	0.43824 (14)	0.0375 (3)
C6	0.33021 (19)	0.67400 (17)	0.56503 (14)	0.0383 (3)
H6	0.4498	0.6385	0.5661	0.046*
C7	0.4516 (2)	0.80226 (18)	0.82010 (15)	0.0422 (3)
H7A	0.5705	0.8107	0.7938	0.051*
H7B	0.4420	0.9171	0.8803	0.051*
C8	0.45863 (19)	0.67338 (17)	0.90187 (14)	0.0395 (3)
C9	0.0631 (2)	0.89595 (17)	0.82393 (14)	0.0400 (3)
C10	−0.3249 (2)	0.8280 (2)	0.43127 (17)	0.0485 (4)
H10A	−0.2602	0.8918	0.3847	0.073*
H10B	−0.4348	0.8822	0.4483	0.073*
H10C	−0.3638	0.7084	0.3733	0.073*
C11	0.1312 (3)	0.5536 (3)	0.18904 (16)	0.0577 (4)
H11A	0.0121	0.4829	0.1722	0.087*
H11B	0.1926	0.5036	0.1168	0.087*
H11C	0.1088	0.6711	0.1887	0.087*
O1	0.57813 (17)	0.73299 (14)	1.02706 (11)	0.0586 (3)
H1	0.591 (3)	0.649 (2)	1.064 (2)	0.088*
O2	0.37228 (14)	0.52591 (12)	0.85679 (10)	0.0478 (3)
O3	0.13985 (17)	0.86083 (14)	0.93203 (11)	0.0546 (3)
O4	−0.05790 (19)	1.00945 (16)	0.82345 (12)	0.0623 (4)
H4A	−0.071 (3)	1.045 (3)	0.9062 (13)	0.093*
O5	−0.20053 (14)	0.83024 (15)	0.56072 (11)	0.0512 (3)
O6	0.24990 (14)	0.55808 (15)	0.32166 (10)	0.0505 (3)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0413 (7)	0.0335 (6)	0.0330 (7)	0.0039 (5)	0.0072 (5)	0.0113 (5)
C2	0.0448 (7)	0.0334 (6)	0.0310 (7)	0.0060 (5)	0.0112 (6)	0.0082 (5)
C3	0.0376 (7)	0.0392 (6)	0.0344 (7)	0.0079 (5)	0.0113 (5)	0.0099 (5)
C4	0.0381 (7)	0.0452 (7)	0.0292 (6)	0.0062 (5)	0.0066 (5)	0.0094 (5)
C5	0.0410 (7)	0.0388 (6)	0.0331 (7)	0.0064 (5)	0.0132 (6)	0.0081 (5)
C6	0.0358 (6)	0.0422 (7)	0.0380 (7)	0.0094 (5)	0.0102 (5)	0.0120 (6)
C7	0.0437 (7)	0.0420 (7)	0.0356 (7)	0.0031 (6)	0.0035 (6)	0.0089 (6)
C8	0.0406 (7)	0.0405 (7)	0.0319 (7)	0.0103 (5)	0.0037 (5)	0.0056 (5)
C9	0.0512 (8)	0.0359 (6)	0.0325 (7)	0.0083 (6)	0.0119 (6)	0.0080 (5)
C10	0.0413 (7)	0.0565 (9)	0.0503 (9)	0.0160 (6)	0.0114 (6)	0.0186 (7)
C11	0.0642 (10)	0.0761 (11)	0.0323 (8)	0.0200 (8)	0.0165 (7)	0.0096 (7)
O1	0.0744 (8)	0.0453 (6)	0.0393 (6)	−0.0015 (5)	−0.0142 (5)	0.0113 (5)
O2	0.0556 (6)	0.0400 (5)	0.0383 (5)	0.0034 (4)	−0.0041 (4)	0.0105 (4)
O3	0.0777 (8)	0.0583 (6)	0.0332 (5)	0.0286 (6)	0.0187 (5)	0.0148 (5)
O4	0.0877 (9)	0.0680 (8)	0.0366 (6)	0.0429 (7)	0.0223 (6)	0.0127 (5)
O5	0.0411 (5)	0.0721 (7)	0.0379 (6)	0.0195 (5)	0.0121 (4)	0.0082 (5)
O6	0.0472 (6)	0.0686 (7)	0.0333 (5)	0.0188 (5)	0.0145 (4)	0.0057 (5)

Geometric parameters (Å, º)

C1—C6	1.3743 (19)	C8—O2	1.2136 (17)
C1—C2	1.4128 (18)	C8—O1	1.3177 (16)
C1—C7	1.5131 (18)	C9—O3	1.2346 (17)
C2—C3	1.4085 (18)	C9—O4	1.2979 (17)
C2—C9	1.4822 (18)	C10—O5	1.4197 (17)
C3—O5	1.3552 (15)	C10—H10A	0.9600
C3—C4	1.3896 (18)	C10—H10B	0.9600
C4—C5	1.3814 (18)	C10—H10C	0.9600
C4—H4	0.9300	C11—O6	1.4243 (18)
C5—O6	1.3625 (16)	C11—H11A	0.9600
C5—C6	1.3888 (19)	C11—H11B	0.9600
C6—H6	0.9300	C11—H11C	0.9600
C7—C8	1.490 (2)	O1—H1	0.853 (10)
C7—H7A	0.9700	O4—H4A	0.850 (10)
C7—H7B	0.9700
C6—C1—C2	120.35 (12)	H7A—C7—H7B	107.5
C6—C1—C7	116.69 (12)	O2—C8—O1	122.97 (13)
C2—C1—C7	122.77 (12)	O2—C8—C7	124.33 (12)
C3—C2—C1	117.97 (12)	O1—C8—C7	112.59 (12)
C3—C2—C9	122.14 (12)	O3—C9—O4	121.67 (12)
C1—C2—C9	119.88 (12)	O3—C9—C2	121.09 (12)
O5—C3—C4	121.37 (12)	O4—C9—C2	117.24 (12)
O5—C3—C2	117.53 (11)	O5—C10—H10A	109.5
C4—C3—C2	121.07 (12)	O5—C10—H10B	109.5
C5—C4—C3	119.49 (12)	H10A—C10—H10B	109.5
C5—C4—H4	120.3	O5—C10—H10C	109.5
C3—C4—H4	120.3	H10A—C10—H10C	109.5
O6—C5—C4	123.65 (12)	H10B—C10—H10C	109.5
O6—C5—C6	115.93 (11)	O6—C11—H11A	109.5
C4—C5—C6	120.42 (12)	O6—C11—H11B	109.5
C1—C6—C5	120.66 (12)	H11A—C11—H11B	109.5
C1—C6—H6	119.7	O6—C11—H11C	109.5
C5—C6—H6	119.7	H11A—C11—H11C	109.5
C8—C7—C1	114.89 (11)	H11B—C11—H11C	109.5
C8—C7—H7A	108.5	C8—O1—H1	108.8 (16)
C1—C7—H7A	108.5	C9—O4—H4A	107.1 (16)
C8—C7—H7B	108.5	C3—O5—C10	117.93 (11)
C1—C7—H7B	108.5	C5—O6—C11	117.71 (11)
C6—C1—C2—C3	−1.54 (19)	O6—C5—C6—C1	179.77 (11)
C7—C1—C2—C3	173.28 (12)	C4—C5—C6—C1	0.5 (2)
C6—C1—C2—C9	177.77 (12)	C6—C1—C7—C8	−97.26 (15)
C7—C1—C2—C9	−7.40 (19)	C2—C1—C7—C8	87.74 (15)
C1—C2—C3—O5	179.67 (11)	C1—C7—C8—O2	15.7 (2)
C9—C2—C3—O5	0.37 (19)	C1—C7—C8—O1	−167.93 (11)
C1—C2—C3—C4	1.48 (19)	C3—C2—C9—O3	149.68 (14)
C9—C2—C3—C4	−177.82 (12)	C1—C2—C9—O3	−29.6 (2)
O5—C3—C4—C5	−178.56 (12)	C3—C2—C9—O4	−31.08 (19)
C2—C3—C4—C5	−0.4 (2)	C1—C2—C9—O4	149.64 (13)
C3—C4—C5—O6	−179.78 (12)	C4—C3—O5—C10	−12.8 (2)
C3—C4—C5—C6	−0.6 (2)	C2—C3—O5—C10	168.99 (12)
C2—C1—C6—C5	0.6 (2)	C4—C5—O6—C11	11.6 (2)
C7—C1—C6—C5	−174.55 (11)	C6—C5—O6—C11	−167.67 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7B···O3	0.97	2.43	2.7829 (19)	101
C10—H10C···O2^i	0.96	2.56	3.4144 (19)	148
O4—H4A···O3^ii	0.85 (1)	1.82 (1)	2.6606 (14)	169 (2)
O1—H1···O2^iii	0.85 (1)	1.80 (1)	2.6532 (14)	178 (2)

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