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

Journal logoCRYSTALLOGRAPHIC
COMMUNICATIONS
ISSN: 2056-9890

Ethyl 3-amino-4-[(2-hy­dr­oxy­ethyl)­amino]benzoate

aSchool of Pharmaceutical Sciences, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bKuliyyah of Science, International Islamic University Malaysia, Jalan Sultan Ahmad Shah, Bandar Indera Mahkota, 25200 Kuantan, Pahang, Malaysia, and cX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia
*Correspondence e-mail: hkfun@usm.my

(Received 20 July 2010; accepted 21 July 2010; online 31 July 2010)

In the crystal structure of the title compound, C11H16N2O3, mol­ecules are linked by one O—H⋯N and two N—H⋯O inter­molecular hydrogen bonds into a three-dimensional network, which incorporates R22(14) and R22(16) graph-set motifs.

Related literature

For the biological activity of amino benzoic acid and benzimid­azole derivatives, see: Kumar et al. (2003[Kumar, A., Bansal, D., Bajaj, K., Sharma, S., Archana & Srivastava, V. K. (2003). Bioorg. Med. Chem. 11, 5281-5291.]); Stefan et al. (2002[Stefan, B., Carmen, G. & Kerstin, K. (2002). Bioorg. Med. Chem. 10, 2415-2437.]); Pan et al. (1999[Pan, P. C. & Sun, C. M. (1999). Tetrahedron Lett. 40, 6443-6446.]). For related structures, see: Narendra Babu et al. (2009[Narendra Babu, S. N., Abdul Rahim, A. S., Abd Hamid, S., Balasubramani, K. & Fun, H.-K. (2009). Acta Cryst. E65, o2070-o2071.]); Abdul Rahim et al. (2010[Abdul Rahim, A. S., Abd Hamid, S., Narendra Babu, S. N., Loh, W.-S. & Fun, H.-K. (2010). Acta Cryst. E66, o846-o847.]). For hydrogen-bond motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]).

[Scheme 1]

Experimental

Crystal data
  • C11H16N2O3

  • Mr = 224.26

  • Monoclinic, C 2/c

  • a = 23.2300 (5) Å

  • b = 14.5914 (4) Å

  • c = 7.5815 (1) Å

  • β = 108.931 (1)°

  • V = 2430.81 (9) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 296 K

  • 0.55 × 0.37 × 0.25 mm

Data collection
  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.953, Tmax = 0.978

  • 26584 measured reflections

  • 3739 independent reflections

  • 2597 reflections with I > 2σ(I)

  • Rint = 0.035

Refinement
  • R[F2 > 2σ(F2)] = 0.045

  • wR(F2) = 0.134

  • S = 1.02

  • 3739 reflections

  • 162 parameters

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

  • Δρmax = 0.16 e Å−3

  • Δρmin = −0.21 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1O1⋯N2i 0.846 (15) 2.017 (15) 2.8628 (14) 178.4 (14)
N2—H1N2⋯O3ii 0.880 (19) 2.145 (19) 3.0083 (16) 167.0 (13)
N2—H2N2⋯O1iii 0.907 (15) 2.113 (15) 2.9800 (14) 159.7 (13)
Symmetry codes: (i) [-x, y, -z-{\script{1\over 2}}]; (ii) [-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z]; (iii) -x, -y, -z.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

Amino benzoic acid derivatives are important intermediates for the synthesis of various heterocyclic compounds of pharmacological interests (Kumar et al., 2003). The synthesis of novel benzimidazole derivatives such as 2-aminomethyl benzimidazoles (Stefan et al., 2002) and oxobenzimidazoles (Pan et al., 1999) are commonly accessed via aminobenzoic acid derivatives. As part of an ongoing study on such compounds, we present the crystal structure of the title compound (I), which was an intermediate in a synthesis.

In the title molecule (Fig. 1), the bond lengths and angles are within normal ranges and are similiar to those in related structures (Narendra Babu et al., 2009; Abdul Rahim et al., 2010). The benzoate group is essentially planar with a maximum deviation of -0.006 (1) for atom C4.

In the crystal structure, molecules are linked by intermolecular N2—H1N2···O3ii, N2—H2N2···O1iii and O1—H1O1···N2i hydrogen bonds (see Table 1 for symmetry codes) into a three-dimensional network with R22(14) and R22(16) graph-set motifs (Bernstein et al., 1995).

Related literature top

For the biological activity of amino benzoic acid and benzimidazole derivatives, see: Kumar et al. (2003); Stefan et al. (2002); Pan et al. (1999). For related structures, see: Narendra Babu et al. (2009); Abdul Rahim et al. (2010). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Experimental top

Ethyl 4-(2-hydroxyethylamino)-3-nitro-benzoate (0.5 g, 1.96 mmol), ammonium formate (0.4 g, 6.8 mmol) and palladium on carbon (250 mg) were mixed in ethanol. The reaction mixture was irradiated under microwave conditions at 373K for 2 minutes. After completion, the reaction mixture was filtered through celite and the filtrate was concentrated under reduced pressure to yield the crude product. The product was recrystallised from EtOAc to afford the title compound as colourless crystals.

Refinement top

N-bound and O-bound H atoms were located from a difference Fourier map and refined isotropically. The remaining H atoms were positioned geometrically [C-H = 0.93, 0.96 or 0.97 Å] and were refined using a riding model, with Uiso(H) = xUeq(C), where x = 1.5 for methyl and 1.2 for all other atoms. A rotating model was used for the methyl group.

Structure description top

Amino benzoic acid derivatives are important intermediates for the synthesis of various heterocyclic compounds of pharmacological interests (Kumar et al., 2003). The synthesis of novel benzimidazole derivatives such as 2-aminomethyl benzimidazoles (Stefan et al., 2002) and oxobenzimidazoles (Pan et al., 1999) are commonly accessed via aminobenzoic acid derivatives. As part of an ongoing study on such compounds, we present the crystal structure of the title compound (I), which was an intermediate in a synthesis.

In the title molecule (Fig. 1), the bond lengths and angles are within normal ranges and are similiar to those in related structures (Narendra Babu et al., 2009; Abdul Rahim et al., 2010). The benzoate group is essentially planar with a maximum deviation of -0.006 (1) for atom C4.

In the crystal structure, molecules are linked by intermolecular N2—H1N2···O3ii, N2—H2N2···O1iii and O1—H1O1···N2i hydrogen bonds (see Table 1 for symmetry codes) into a three-dimensional network with R22(14) and R22(16) graph-set motifs (Bernstein et al., 1995).

For the biological activity of amino benzoic acid and benzimidazole derivatives, see: Kumar et al. (2003); Stefan et al. (2002); Pan et al. (1999). For related structures, see: Narendra Babu et al. (2009); Abdul Rahim et al. (2010). For hydrogen-bond motifs, see: Bernstein et al. (1995).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure, showing 50% probability displacement ellipsoids and the atom-numbering scheme. Hydrogen atoms are shown as spheres of arbitrary radius.
[Figure 2] Fig. 2. The crystal packing of (I) viewed along the c axis. Dashed lines indicate hydrogen bonds. H atoms not involved in the hydrogen bond interactions have been omitted for clarity.
Ethyl 3-amino-4-[(2-hydroxyethyl)amino]benzoate top
Crystal data top
C11H16N2O3F(000) = 960
Mr = 224.26Dx = 1.226 Mg m3
Monoclinic, C2/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2ycCell parameters from 8941 reflections
a = 23.2300 (5) Åθ = 2.8–30.6°
b = 14.5914 (4) ŵ = 0.09 mm1
c = 7.5815 (1) ÅT = 296 K
β = 108.931 (1)°Block, colourless
V = 2430.81 (9) Å30.55 × 0.37 × 0.25 mm
Z = 8
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
3739 independent reflections
Radiation source: fine-focus sealed tube2597 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.035
φ and ω scansθmax = 30.6°, θmin = 1.7°
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
h = 3233
Tmin = 0.953, Tmax = 0.978k = 2020
26584 measured reflectionsl = 1010
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)] = 0.045Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.134H atoms treated by a mixture of independent and constrained refinement
S = 1.02 w = 1/[σ2(Fo2) + (0.0626P)2 + 0.4393P]
where P = (Fo2 + 2Fc2)/3
3739 reflections(Δ/σ)max < 0.001
162 parametersΔρmax = 0.16 e Å3
0 restraintsΔρmin = 0.21 e Å3
Crystal data top
C11H16N2O3V = 2430.81 (9) Å3
Mr = 224.26Z = 8
Monoclinic, C2/cMo Kα radiation
a = 23.2300 (5) ŵ = 0.09 mm1
b = 14.5914 (4) ÅT = 296 K
c = 7.5815 (1) Å0.55 × 0.37 × 0.25 mm
β = 108.931 (1)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
3739 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
2597 reflections with I > 2σ(I)
Tmin = 0.953, Tmax = 0.978Rint = 0.035
26584 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0450 restraints
wR(F2) = 0.134H atoms treated by a mixture of independent and constrained refinement
S = 1.02Δρmax = 0.16 e Å3
3739 reflectionsΔρmin = 0.21 e Å3
162 parameters
Special details top

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. 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 > 2sigma(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
O10.07544 (4)0.04108 (6)0.13906 (13)0.0595 (2)
O20.17663 (4)0.52426 (6)0.03582 (14)0.0667 (3)
O30.24606 (4)0.41940 (7)0.03351 (18)0.0826 (3)
N10.01804 (4)0.17082 (8)0.01775 (14)0.0544 (2)
N20.13085 (5)0.11676 (7)0.00330 (14)0.0540 (2)
C10.07977 (6)0.10608 (9)0.00450 (17)0.0581 (3)
H1A0.06430.07890.11860.070*
H1B0.12230.12120.02770.070*
C20.04490 (5)0.19272 (8)0.00811 (16)0.0521 (3)
H2A0.06270.22370.12660.063*
H2B0.04720.23360.09030.063*
C30.05994 (5)0.23731 (8)0.01945 (15)0.0490 (3)
C40.04734 (5)0.33047 (8)0.02461 (19)0.0600 (3)
H4A0.00910.34870.02580.072*
C50.09038 (6)0.39616 (9)0.0280 (2)0.0623 (3)
H5A0.08090.45790.03080.075*
C60.14783 (5)0.37052 (8)0.02717 (16)0.0539 (3)
C70.16117 (5)0.27727 (8)0.02449 (15)0.0518 (3)
H7A0.19970.25970.02540.062*
C80.11884 (5)0.21078 (8)0.02050 (14)0.0479 (2)
C90.19533 (5)0.43832 (9)0.03180 (17)0.0575 (3)
C100.21965 (6)0.59737 (9)0.0476 (2)0.0668 (3)
H10A0.23360.59630.05980.080*
H10B0.25460.59100.15950.080*
C110.18689 (8)0.68429 (11)0.0526 (3)0.0838 (5)
H11A0.21490.73470.07330.126*
H11B0.16970.68170.15190.126*
H11C0.15500.69260.06400.126*
H1O10.0924 (7)0.0638 (11)0.246 (2)0.075 (4)*
H1N10.0238 (6)0.1165 (11)0.0138 (19)0.065 (4)*
H1N20.1691 (8)0.1076 (10)0.012 (2)0.072 (4)*
H2N20.1176 (7)0.0761 (10)0.072 (2)0.071 (4)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0687 (5)0.0560 (5)0.0529 (5)0.0008 (4)0.0184 (4)0.0009 (4)
O20.0536 (5)0.0594 (5)0.0905 (7)0.0071 (4)0.0280 (4)0.0010 (4)
O30.0551 (5)0.0787 (7)0.1247 (9)0.0041 (4)0.0441 (5)0.0072 (6)
N10.0481 (5)0.0538 (6)0.0645 (6)0.0011 (4)0.0226 (4)0.0009 (4)
N20.0508 (5)0.0569 (6)0.0567 (6)0.0036 (4)0.0210 (4)0.0002 (4)
C10.0572 (6)0.0655 (7)0.0577 (7)0.0079 (5)0.0270 (5)0.0043 (5)
C20.0481 (6)0.0587 (6)0.0534 (6)0.0015 (5)0.0218 (5)0.0029 (5)
C30.0452 (5)0.0574 (6)0.0461 (5)0.0014 (4)0.0172 (4)0.0015 (4)
C40.0462 (6)0.0590 (7)0.0794 (8)0.0021 (5)0.0266 (6)0.0004 (6)
C50.0533 (6)0.0541 (7)0.0839 (8)0.0020 (5)0.0285 (6)0.0005 (6)
C60.0475 (6)0.0594 (7)0.0575 (6)0.0028 (5)0.0207 (5)0.0018 (5)
C70.0436 (5)0.0638 (7)0.0501 (6)0.0018 (5)0.0180 (4)0.0015 (5)
C80.0474 (5)0.0561 (6)0.0411 (5)0.0021 (4)0.0154 (4)0.0011 (4)
C90.0510 (6)0.0643 (7)0.0600 (7)0.0028 (5)0.0219 (5)0.0024 (5)
C100.0603 (7)0.0693 (8)0.0737 (8)0.0151 (6)0.0257 (6)0.0026 (6)
C110.0976 (11)0.0696 (9)0.0974 (12)0.0124 (8)0.0499 (9)0.0071 (8)
Geometric parameters (Å, º) top
O1—C11.4203 (15)C3—C41.3938 (17)
O1—H1O10.844 (17)C3—C81.4194 (15)
O2—C91.3306 (16)C4—C51.3792 (17)
O2—C101.4447 (15)C4—H4A0.9300
O3—C91.2065 (15)C5—C61.3880 (16)
N1—C31.3714 (14)C5—H5A0.9300
N1—C21.4465 (14)C6—C71.3972 (18)
N1—H1N10.851 (15)C6—C91.4738 (17)
N2—C81.4144 (15)C7—C81.3747 (16)
N2—H1N20.880 (17)C7—H7A0.9300
N2—H2N20.907 (16)C10—C111.486 (2)
C1—C21.5064 (17)C10—H10A0.9700
C1—H1A0.9700C10—H10B0.9700
C1—H1B0.9700C11—H11A0.9600
C2—H2A0.9700C11—H11B0.9600
C2—H2B0.9700C11—H11C0.9600
C1—O1—H1O1107.8 (11)C4—C5—H5A119.8
C9—O2—C10118.22 (10)C6—C5—H5A119.8
C3—N1—C2121.87 (10)C5—C6—C7118.72 (11)
C3—N1—H1N1119.1 (10)C5—C6—C9122.18 (11)
C2—N1—H1N1114.3 (10)C7—C6—C9119.10 (10)
C8—N2—H1N2111.4 (10)C8—C7—C6121.82 (10)
C8—N2—H2N2117.9 (9)C8—C7—H7A119.1
H1N2—N2—H2N2112.2 (13)C6—C7—H7A119.1
O1—C1—C2112.55 (9)C7—C8—N2121.69 (10)
O1—C1—H1A109.1C7—C8—C3119.27 (10)
C2—C1—H1A109.1N2—C8—C3118.86 (10)
O1—C1—H1B109.1O3—C9—O2122.72 (12)
C2—C1—H1B109.1O3—C9—C6124.60 (12)
H1A—C1—H1B107.8O2—C9—C6112.68 (10)
N1—C2—C1109.76 (10)O2—C10—C11106.38 (11)
N1—C2—H2A109.7O2—C10—H10A110.5
C1—C2—H2A109.7C11—C10—H10A110.5
N1—C2—H2B109.7O2—C10—H10B110.5
C1—C2—H2B109.7C11—C10—H10B110.5
H2A—C2—H2B108.2H10A—C10—H10B108.6
N1—C3—C4122.37 (10)C10—C11—H11A109.5
N1—C3—C8119.14 (10)C10—C11—H11B109.5
C4—C3—C8118.47 (10)H11A—C11—H11B109.5
C5—C4—C3121.38 (11)C10—C11—H11C109.5
C5—C4—H4A119.3H11A—C11—H11C109.5
C3—C4—H4A119.3H11B—C11—H11C109.5
C4—C5—C6120.33 (11)
C3—N1—C2—C1179.71 (10)C6—C7—C8—C30.13 (16)
O1—C1—C2—N156.17 (13)N1—C3—C8—C7179.22 (10)
C2—N1—C3—C49.84 (17)C4—C3—C8—C70.70 (16)
C2—N1—C3—C8171.70 (10)N1—C3—C8—N25.47 (15)
N1—C3—C4—C5179.39 (12)C4—C3—C8—N2176.01 (10)
C8—C3—C4—C50.93 (18)C10—O2—C9—O31.65 (19)
C3—C4—C5—C60.3 (2)C10—O2—C9—C6177.74 (10)
C4—C5—C6—C70.54 (19)C5—C6—C9—O3179.09 (13)
C4—C5—C6—C9179.63 (12)C7—C6—C9—O30.0 (2)
C5—C6—C7—C80.76 (17)C5—C6—C9—O20.29 (17)
C9—C6—C7—C8179.87 (10)C7—C6—C9—O2179.38 (10)
C6—C7—C8—N2175.04 (10)C9—O2—C10—C11179.15 (12)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1O1···N2i0.846 (15)2.017 (15)2.8628 (14)178.4 (14)
N2—H1N2···O3ii0.880 (19)2.145 (19)3.0083 (16)167.0 (13)
N2—H2N2···O1iii0.907 (15)2.113 (15)2.9800 (14)159.7 (13)
Symmetry codes: (i) x, y, z1/2; (ii) x+1/2, y+1/2, z; (iii) x, y, z.

Experimental details

Crystal data
Chemical formulaC11H16N2O3
Mr224.26
Crystal system, space groupMonoclinic, C2/c
Temperature (K)296
a, b, c (Å)23.2300 (5), 14.5914 (4), 7.5815 (1)
β (°) 108.931 (1)
V3)2430.81 (9)
Z8
Radiation typeMo Kα
µ (mm1)0.09
Crystal size (mm)0.55 × 0.37 × 0.25
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.953, 0.978
No. of measured, independent and
observed [I > 2σ(I)] reflections
26584, 3739, 2597
Rint0.035
(sin θ/λ)max1)0.717
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.045, 0.134, 1.02
No. of reflections3739
No. of parameters162
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.16, 0.21

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1O1···N2i0.846 (15)2.017 (15)2.8628 (14)178.4 (14)
N2—H1N2···O3ii0.880 (19)2.145 (19)3.0083 (16)167.0 (13)
N2—H2N2···O1iii0.907 (15)2.113 (15)2.9800 (14)159.7 (13)
Symmetry codes: (i) x, y, z1/2; (ii) x+1/2, y+1/2, z; (iii) x, y, z.
 

Footnotes

Additional correspondence author, e-mail: aisyah@usm.my.

§Thomson Reuters ResearcherID: A-3561-2009.

Acknowledgements

NA, ASAR and SAH gratefully acknowledge the Ministry of Science, Technology and Innovations (MOSTI) Grant 304/PFARMASI/650512/I121 and the FRGS Grant (FRGS0510–119) for funding the synthetic chemistry work. NA thanks Universiti Sains Malaysia for the award of postdoctoral fellowship. HKF and MMR thank Universiti Sains Malaysia (USM) for the Research University Golden Goose Grant (1001/PFIZIK/811012).

References

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