organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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3-Hy­dr­oxy-2-meth­­oxy­benzamide

aFachrichtung Chemie, Universität des Saarlandes, Postfach 151150, D-66041 Saarbrücken, Germany
*Correspondence e-mail: hegetschweiler@mx.uni-saarland.de

(Received 30 October 2012; accepted 20 November 2012; online 30 November 2012)

The crystal structure of the title compound, C8H9NO3, features centrosymmetric dimers with two amide groups inter­connected by a pair of almost linear N—H⋯O hydrogen bonds. Through inter­molecular O—H⋯O inter­actions between phenolic hy­droxy groups and carbonyl O atoms, these dimers are assembled into undulating hydrogen-bonded layers parallel to the [101] plane. Additionally, the anti-H(—N) atom of the primary amide group forms an intra­molecular hydrogen bond to the O atom of the meth­oxy group. The amide group froms a dihedral angle of 12.6 (1)° with the phenyl ring.

Related literature

Hydrogen-bonding packing patterns of primary amides are discussed by Eccles et al. (2011[Eccles, K. S., Elcoate, C. J., Maguire, A. R. & Lawrence, S. E. (2011). Cryst. Growth Des. 11, 4433-4439.]) and McMahon et al. (2005[McMahon, J. A., Bis, J. A., Vishweshwar, P., Shattock, T. R., McLaughlin, O. L. & Zaworotko, M. J. (2005). Z. Kristallogr. 220, 340-350.]). A description of the Cambridge Crystallographic Database is given by Allen (2002[Allen, F. H. (2002). Acta Cryst. B58, 380-388.]). The question of the occurrence of very bent, intra­molecular C—H⋯O hydrogen bonds has been discussed by Desiraju (1996[Desiraju, G. R. (1996). Acc. Chem. Res. 29, 441-449.]).

[Scheme 1]

Experimental

Crystal data
  • C8H9NO3

  • Mr = 167.16

  • Monoclinic, P 21 /n

  • a = 5.6293 (2) Å

  • b = 10.1826 (4) Å

  • c = 13.2402 (5) Å

  • β = 92.750 (1)°

  • V = 758.07 (5) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.11 mm−1

  • T = 110 K

  • 0.49 × 0.18 × 0.14 mm

Data collection
  • Bruker APEXII KappaCCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2010[Bruker (2010). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.947, Tmax = 0.984

  • 7200 measured reflections

  • 1484 independent reflections

  • 1325 reflections with I > 2σ(I)

  • Rint = 0.022

Refinement
  • R[F2 > 2σ(F2)] = 0.030

  • wR(F2) = 0.083

  • S = 1.06

  • 1484 reflections

  • 122 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.27 e Å−3

  • Δρmin = −0.19 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1A⋯O3i 0.901 (17) 2.056 (17) 2.9547 (13) 175.3 (14)
N1—H1B⋯O1 0.887 (17) 1.977 (17) 2.6789 (13) 135.0 (14)
O2—H2⋯O3ii 0.88 (2) 1.83 (2) 2.6895 (12) 165.5 (17)
Symmetry codes: (i) -x+1, -y+2, -z+1; (ii) [x-{\script{1\over 2}}, -y+{\script{3\over 2}}, z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2010[Bruker (2010). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2010[Bruker (2010). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 2012[Brandenburg, K. (2012). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

The formation of hydrogen-bonded head-to-head dimers is well established for primary amides. A comprehensive search (McMahon et al., 2005) in the Cambridge Structural Database (Allen, 2002) revealed that 84% of the primary amides form such dimers. In addition, 14% form a catemeric (infinite chain) structure. It has recently been demonstrated that the dimers may, however, readily be disrupted in the presence of additional hydrogen-accepting functional groups (Eccles et al., 2011). Although the title compound possesses two such additional groups, the head-to-head dimer formation in the crystal structure is retained.

In the title compound, the two plains defined by the phenyl ring (C1 - C6) and the amide group (C1, C7, O3, N1) are slightly tilted against each other with an angle of 12.6 (1)°. Since the amide, methoxy and hydroxy group are arranged in a consecutive 1,2,3-arrangement, the ether oxygen atom of the methoxy group would be capable to accept either the O—H or N—H proton from the two adjacent moieties, forming a five- or six-membered ring structure, respectively. It is generally accepted that the latter is favoured, and this has indeed been observed. Owing to the steric demands of the 1,2,3-arrangement, the methoxy methyl group is significantly displaced from the aromatic plain, avoiding congestion: The distance of the methyl carbon atom to the aromatic mean plane is 0.819 (2) Å. This is a common feature for 3-alkoxy- or 3-hydroxy-2-methoxybenzamides. A search in the Cambridge Structural Database revealed a total of 46 entries for this structure type, and all of them show a similar displacement. An unexpected feature in the title compound is, however, the orientation of the three hydrogen atoms of the methyl group with an H8C—C8—O1—C2 torsional angle of 24.2 °. This value approaches an eclipsed rather than a staggered conformation. In the final refinement, these hydrogen atoms were treated as rigid group which was, however, allowed to rotate freely. It is clear that the effect under discussion is related to a rather small amount of electron density. However, a corresponding refinement, where the three hydrogen atoms were forced to adopt a staggered orientation, resulted in an increase of wR2(all) from 8.28 to 13.75%! Moreover, full refinement of the positional parameters revealed again the previously obtained, non-staggered arrangement (H8C—C8—O1—C2 torsional angle = 25.4 °, wR2(all) = 8.12%). Notably, in the above-mentioned 46 structures found in our CSD search, only three of them (LUDXEN, IPUQEP, SIGKIC) exhibit a similar deviation from a staggered orientation. Obviously, attractive and repulsive interactions account for this particular structure, and it is tempting to interpret the H8A···O2 distance of 2.49 Å in terms of some intramolecular C—H···O hydrogen bonding. However, the small C8—H8A···O2 angle of 98 ° indicates that such an interaction would be - if at all - rather weak (Desiraju, 1996).

Related literature top

Hydrogen-bonding packing patterns of primary amides are discussed by Eccles et al. (2011) and McMahon et al. (2005). A description of the Cambridge Crystallographic Database is given by Allen (2002). The question of the occurrence of strongly bent, intramolecular C—H···O hydrogen bonds has been discussed by Desiraju (1996).

Experimental top

2,3-Bis(benzyloxy)benzoic acid was obtained from 2,3-dihydroxybenzoic acid (K2CO3, benzyl bromide). It was converted into the corresponding amide via the acid chloride using thionyl chloride and subsequently an aqueous ammonia solution. The benzyl groups were then removed (ammonium formiate, Pd/C), and the resulting 2,3-dihydroxybenzamide was methylated in DMF using iodomethane and potassium bicarbonate. Some by-products were removed by chromatographic methods (SiO2, hexane / Et2O), and the title compound was obtained as a colourless solid. 1H-NMR (DMSO-d6): δ (p.p.m.) = 3.76 (s, 3H), 6.95 (m, 2H), 7.06 (dd, 1H), 7.43 (NH), 7.65 (NH). 13C-NMR (DMSO-d6): δ (p.p.m.) = 60.7, 118.8, 119.7, 123.9, 129.5, 145.6, 150.4, 167.3. Single crystals were grown from Et2O.

Refinement top

The 3-hydroxy-2-methoxybenzamide molecule could be refined without problems, and its hydrogen atoms could all be located. The H(—C) positions were calculated (riding model). The methyl group was allowed to rotate freely. All positional parameters of the O- and N-bonded H-atoms were refined using variable isotropic displacement parameters.

Computing details top

Data collection: APEX2 (Bruker, 2010); cell refinement: SAINT (Bruker, 2010); data reduction: SAINT (Bruker, 2010); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 2012); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Ellipsoid plot (50% probability level) and numbering scheme of the title compound.
[Figure 2] Fig. 2. A section of the hydrogen-bonding network.
3-Hydroxy-2-methoxybenzamide top
Crystal data top
C8H9NO3F(000) = 352
Mr = 167.16Dx = 1.465 Mg m3
Monoclinic, P21/nMo Kα radiation, λ = 0.71073 Å
a = 5.6293 (2) ÅCell parameters from 3853 reflections
b = 10.1826 (4) Åθ = 2.5–32.5°
c = 13.2402 (5) ŵ = 0.11 mm1
β = 92.750 (1)°T = 110 K
V = 758.07 (5) Å3Prism, colourless
Z = 40.49 × 0.18 × 0.14 mm
Data collection top
Bruker APEXII KappaCCD
diffractometer
1484 independent reflections
Radiation source: fine-focus sealed tube1325 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.022
phi and ω scansθmax = 26.0°, θmin = 2.5°
Absorption correction: multi-scan
(SADABS; Bruker, 2010)
h = 66
Tmin = 0.947, Tmax = 0.984k = 1212
7200 measured reflectionsl = 1516
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.030Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.083H atoms treated by a mixture of independent and constrained refinement
S = 1.06 w = 1/[σ2(Fo2) + (0.0421P)2 + 0.2806P]
where P = (Fo2 + 2Fc2)/3
1484 reflections(Δ/σ)max = 0.001
122 parametersΔρmax = 0.27 e Å3
0 restraintsΔρmin = 0.19 e Å3
Crystal data top
C8H9NO3V = 758.07 (5) Å3
Mr = 167.16Z = 4
Monoclinic, P21/nMo Kα radiation
a = 5.6293 (2) ŵ = 0.11 mm1
b = 10.1826 (4) ÅT = 110 K
c = 13.2402 (5) Å0.49 × 0.18 × 0.14 mm
β = 92.750 (1)°
Data collection top
Bruker APEXII KappaCCD
diffractometer
1484 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2010)
1325 reflections with I > 2σ(I)
Tmin = 0.947, Tmax = 0.984Rint = 0.022
7200 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0300 restraints
wR(F2) = 0.083H atoms treated by a mixture of independent and constrained refinement
S = 1.06Δρmax = 0.27 e Å3
1484 reflectionsΔρmin = 0.19 e Å3
122 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
O10.17410 (14)0.98464 (8)0.80141 (6)0.0160 (2)
O20.12850 (15)0.83936 (9)0.91393 (6)0.0192 (2)
H20.195 (3)0.7717 (19)0.9432 (13)0.046 (5)*
O30.23900 (15)0.88839 (8)0.49736 (6)0.0194 (2)
N10.35604 (19)1.02761 (11)0.62107 (8)0.0207 (3)
H1A0.474 (3)1.0570 (15)0.5835 (12)0.031 (4)*
H1B0.346 (3)1.0515 (16)0.6851 (13)0.031 (4)*
C10.0386 (2)0.87000 (11)0.65116 (9)0.0149 (3)
C20.03195 (19)0.88969 (11)0.75592 (8)0.0137 (3)
C30.1284 (2)0.81706 (11)0.81214 (9)0.0156 (3)
C40.2821 (2)0.72817 (12)0.76327 (9)0.0182 (3)
H40.38760.67750.80140.022*
C50.2824 (2)0.71313 (12)0.65908 (9)0.0203 (3)
H50.39180.65460.62580.024*
C60.1234 (2)0.78327 (12)0.60378 (9)0.0185 (3)
H60.12430.77230.53250.022*
C70.2192 (2)0.93056 (11)0.58521 (9)0.0158 (3)
C80.3210 (2)0.94758 (13)0.88935 (9)0.0213 (3)
H8A0.23920.97000.95070.032*
H8B0.47270.99480.88900.032*
H8C0.35080.85280.88790.032*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0186 (4)0.0168 (4)0.0125 (4)0.0020 (3)0.0006 (3)0.0004 (3)
O20.0235 (5)0.0217 (5)0.0125 (4)0.0022 (4)0.0045 (3)0.0010 (3)
O30.0241 (5)0.0209 (5)0.0138 (4)0.0026 (3)0.0063 (3)0.0024 (3)
N10.0247 (6)0.0232 (6)0.0150 (5)0.0082 (4)0.0083 (4)0.0027 (4)
C10.0167 (6)0.0138 (6)0.0146 (6)0.0017 (4)0.0033 (4)0.0007 (4)
C20.0137 (5)0.0121 (5)0.0152 (6)0.0019 (4)0.0002 (4)0.0008 (4)
C30.0183 (6)0.0160 (6)0.0126 (5)0.0036 (5)0.0026 (4)0.0010 (4)
C40.0185 (6)0.0172 (6)0.0193 (6)0.0015 (5)0.0053 (5)0.0025 (5)
C50.0213 (6)0.0185 (6)0.0210 (6)0.0052 (5)0.0012 (5)0.0022 (5)
C60.0231 (6)0.0196 (6)0.0128 (6)0.0014 (5)0.0021 (5)0.0018 (5)
C70.0180 (6)0.0156 (6)0.0138 (6)0.0018 (4)0.0024 (4)0.0010 (5)
C80.0192 (6)0.0277 (7)0.0165 (6)0.0008 (5)0.0035 (5)0.0012 (5)
Geometric parameters (Å, º) top
O1—C21.3753 (14)C2—C31.4074 (16)
O1—C81.4456 (14)C3—C41.3903 (17)
O2—C31.3668 (14)C4—C51.3879 (17)
O2—H20.88 (2)C4—H40.9500
O3—C71.2499 (14)C5—C61.3822 (17)
N1—C71.3267 (16)C5—H50.9500
N1—H1A0.901 (17)C6—H60.9500
N1—H1B0.887 (17)C8—H8A0.9800
C1—C61.3963 (17)C8—H8B0.9800
C1—C21.4038 (16)C8—H8C0.9800
C1—C71.5041 (16)
C2—O1—C8117.88 (9)C3—C4—H4119.8
C3—O2—H2108.9 (12)C6—C5—C4119.98 (11)
C7—N1—H1A118.7 (10)C6—C5—H5120.0
C7—N1—H1B118.8 (10)C4—C5—H5120.0
H1A—N1—H1B121.5 (14)C5—C6—C1120.95 (11)
C6—C1—C2119.12 (10)C5—C6—H6119.5
C6—C1—C7116.33 (10)C1—C6—H6119.5
C2—C1—C7124.46 (11)O3—C7—N1120.85 (11)
O1—C2—C1119.38 (10)O3—C7—C1119.49 (10)
O1—C2—C3120.82 (10)N1—C7—C1119.65 (10)
C1—C2—C3119.71 (11)O1—C8—H8A109.5
O2—C3—C4122.52 (11)O1—C8—H8B109.5
O2—C3—C2117.69 (10)H8A—C8—H8B109.5
C4—C3—C2119.78 (11)O1—C8—H8C109.5
C5—C4—C3120.36 (11)H8A—C8—H8C109.5
C5—C4—H4119.8H8B—C8—H8C109.5
C8—O1—C2—C1129.31 (11)O2—C3—C4—C5177.18 (11)
C8—O1—C2—C354.02 (14)C2—C3—C4—C51.63 (18)
C6—C1—C2—O1173.41 (10)C3—C4—C5—C62.32 (19)
C7—C1—C2—O110.24 (17)C4—C5—C6—C10.16 (19)
C6—C1—C2—C33.30 (17)C2—C1—C6—C52.65 (18)
C7—C1—C2—C3173.05 (10)C7—C1—C6—C5173.99 (11)
O1—C2—C3—O23.41 (16)C6—C1—C7—O39.95 (17)
C1—C2—C3—O2179.93 (10)C2—C1—C7—O3166.50 (11)
O1—C2—C3—C4175.47 (10)C6—C1—C7—N1170.31 (11)
C1—C2—C3—C41.20 (17)C2—C1—C7—N113.25 (18)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O3i0.901 (17)2.056 (17)2.9547 (13)175.3 (14)
N1—H1B···O10.887 (17)1.977 (17)2.6789 (13)135.0 (14)
O2—H2···O3ii0.88 (2)1.83 (2)2.6895 (12)165.5 (17)
Symmetry codes: (i) x+1, y+2, z+1; (ii) x1/2, y+3/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC8H9NO3
Mr167.16
Crystal system, space groupMonoclinic, P21/n
Temperature (K)110
a, b, c (Å)5.6293 (2), 10.1826 (4), 13.2402 (5)
β (°) 92.750 (1)
V3)758.07 (5)
Z4
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.49 × 0.18 × 0.14
Data collection
DiffractometerBruker APEXII KappaCCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2010)
Tmin, Tmax0.947, 0.984
No. of measured, independent and
observed [I > 2σ(I)] reflections
7200, 1484, 1325
Rint0.022
(sin θ/λ)max1)0.616
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.030, 0.083, 1.06
No. of reflections1484
No. of parameters122
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.27, 0.19

Computer programs: APEX2 (Bruker, 2010), SAINT (Bruker, 2010), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg, 2012).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O3i0.901 (17)2.056 (17)2.9547 (13)175.3 (14)
N1—H1B···O10.887 (17)1.977 (17)2.6789 (13)135.0 (14)
O2—H2···O3ii0.88 (2)1.83 (2)2.6895 (12)165.5 (17)
Symmetry codes: (i) x+1, y+2, z+1; (ii) x1/2, y+3/2, z+1/2.
 

Acknowledgements

We thank Dr Volker Huch (Universität des Saarlandes) for the data collection.

References

First citationAllen, F. H. (2002). Acta Cryst. B58, 380–388.  Web of Science CrossRef CAS IUCr Journals
First citationBrandenburg, K. (2012). DIAMOND. Crystal Impact GbR, Bonn, Germany.
First citationBruker (2010). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
First citationDesiraju, G. R. (1996). Acc. Chem. Res. 29, 441–449.  CrossRef CAS PubMed Web of Science
First citationEccles, K. S., Elcoate, C. J., Maguire, A. R. & Lawrence, S. E. (2011). Cryst. Growth Des. 11, 4433–4439.  Web of Science CSD CrossRef CAS
First citationMcMahon, J. A., Bis, J. A., Vishweshwar, P., Shattock, T. R., McLaughlin, O. L. & Zaworotko, M. J. (2005). Z. Kristallogr. 220, 340–350.  Web of Science CSD CrossRef CAS
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals

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ISSN: 2056-9890
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