organic compounds
A correction has been published for this article. To view the correction, click here.
3-(tert-Butoxycarbonyl)-2-(4-chlorophenyl)-1,3-thiazolidine-4-carboxylic acid
aSchool of Chemical Engineering, Changzhou University, Changzhou 213164, People's Republic of China
*Correspondence e-mail: dsm@cczu.edu.cn
In the title compound, C15H18ClNO4S, the thiazolidine ring adopts a twisted conformation about the S—C(methylene) bond. The dihedral angle between the five- and six-membered rings is 77.2 (3)°. In the crystal, the molecules are linked by O—H⋯O hydrogen bonds, generating C(7) chains propagating in [100].
Related literature
For background to the biological properties of the title compound, see: Lu et al. (2010); Song et al. (2009). For reference bond-length data, see: Allen et al. (1987).
Experimental
Crystal data
|
Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
10.1107/S1600536810037396/hb5637sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536810037396/hb5637Isup2.hkl
A mixture of L-cysteine (1.41 g, 10 mmol) and 4-chlorobenzaldehyde (1.4 g, 10 mmol) in methanol (100 ml) was stirred at room temperature for 10 h, and the separated solid was collected, washed with diethyl ether, and dried to obtain 2-(4-chlorophenyl)thiazolidine-4-carboxylic with yield of 90%. In ice water, 2-(4-chlorophenyl)thiazolidine-4-carboxylic (1 mmol) was dissolved in 1 N NaOH (1 ml) and 1,4-dioxane (10 ml); then di-tert-butyldicarbonate (1 mmol) was added slowly and stirred at room temperature for 6 h. The reaction mixture was concentrated in a vacuum and washed with ethyl acetate (10 ml). The aqueous phase was adjusted to pH 4 by adding 1 N HCl, then extracted with ethyl acetate, dried with magnesium sulfate, filtered, After keeping the filtrate in air for 5 d, colorless block-shaped crystals of (I) were formed.
All H atoms were positioned geometrically (C—H = 0.93 Å for the aromatic H atoms and C—H = 0.96 Å for the aliphatic H atoms) and were refined as riding, with Uiso(H) = 1.2Ueq(C) and Uiso(H) = 1.2Ueq(N).
Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell
CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C15H18ClNO4S | F(000) = 360 |
Mr = 343.81 | Dx = 1.343 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 25 reflections |
a = 6.4600 (13) Å | θ = 9–12° |
b = 10.641 (2) Å | µ = 0.36 mm−1 |
c = 12.411 (3) Å | T = 293 K |
β = 94.52 (3)° | Block, colorless |
V = 850.5 (3) Å3 | 0.30 × 0.20 × 0.10 mm |
Z = 2 |
Enraf–Nonius CAD-4 diffractometer | 1363 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.000 |
Graphite monochromator | θmax = 25.3°, θmin = 1.7° |
ω/2θ scan | h = −7→7 |
Absorption correction: ψ scan (North et al., 1968) | k = 0→12 |
Tmin = 0.899, Tmax = 0.965 | l = 0→14 |
1638 measured reflections | 200 standard reflections every 3 reflections |
1638 independent reflections | intensity decay: 1% |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.062 | H-atom parameters constrained |
wR(F2) = 0.159 | w = 1/[σ2(Fo2) + (0.0649P)2 + 1.2912P] where P = (Fo2 + 2Fc2)/3 |
S = 1.08 | (Δ/σ)max < 0.001 |
1638 reflections | Δρmax = 0.43 e Å−3 |
185 parameters | Δρmin = −0.37 e Å−3 |
89 restraints | Absolute structure: Flack (1983) |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: −0.09 (19) |
C15H18ClNO4S | V = 850.5 (3) Å3 |
Mr = 343.81 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 6.4600 (13) Å | µ = 0.36 mm−1 |
b = 10.641 (2) Å | T = 293 K |
c = 12.411 (3) Å | 0.30 × 0.20 × 0.10 mm |
β = 94.52 (3)° |
Enraf–Nonius CAD-4 diffractometer | 1363 reflections with I > 2σ(I) |
Absorption correction: ψ scan (North et al., 1968) | Rint = 0.000 |
Tmin = 0.899, Tmax = 0.965 | 200 standard reflections every 3 reflections |
1638 measured reflections | intensity decay: 1% |
1638 independent reflections |
R[F2 > 2σ(F2)] = 0.062 | H-atom parameters constrained |
wR(F2) = 0.159 | Δρmax = 0.43 e Å−3 |
S = 1.08 | Δρmin = −0.37 e Å−3 |
1638 reflections | Absolute structure: Flack (1983) |
185 parameters | Absolute structure parameter: −0.09 (19) |
89 restraints |
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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.3575 (11) | 0.4607 (7) | 0.7980 (6) | 0.0457 (16) | |
H1 | 0.4776 | 0.4984 | 0.7768 | 0.055* | |
C2 | 0.3229 (12) | 0.3336 (8) | 0.7816 (6) | 0.0519 (17) | |
H2 | 0.4183 | 0.2863 | 0.7465 | 0.062* | |
C3 | 0.1505 (12) | 0.2766 (8) | 0.8162 (7) | 0.0555 (18) | |
C4 | 0.0021 (13) | 0.3440 (8) | 0.8654 (6) | 0.0585 (18) | |
H4 | −0.1163 | 0.3054 | 0.8879 | 0.070* | |
C5 | 0.0368 (11) | 0.4720 (7) | 0.8800 (6) | 0.0492 (16) | |
H5 | −0.0604 | 0.5195 | 0.9136 | 0.059* | |
C6 | 0.2109 (9) | 0.5308 (6) | 0.8464 (5) | 0.0349 (13) | |
C7 | 0.2361 (9) | 0.6677 (6) | 0.8692 (4) | 0.0358 (13) | |
H7 | 0.1036 | 0.7023 | 0.8887 | 0.043* | |
C8 | 0.4770 (9) | 0.8351 (7) | 0.8161 (5) | 0.0409 (14) | |
H8 | 0.4364 | 0.9165 | 0.7842 | 0.049* | |
O1 | 0.8408 (8) | 0.8639 (5) | 0.8109 (4) | 0.060 | |
C9 | 0.4827 (11) | 0.8471 (7) | 0.9375 (5) | 0.0494 (16) | |
H9A | 0.3760 | 0.9043 | 0.9583 | 0.059* | |
H9B | 0.6170 | 0.8774 | 0.9671 | 0.059* | |
C10 | 0.6910 (9) | 0.8031 (8) | 0.7835 (5) | 0.0459 (17) | |
C11 | 0.2163 (9) | 0.7473 (7) | 0.6838 (5) | 0.0373 (14) | |
C12 | 0.2095 (11) | 0.8500 (8) | 0.5098 (5) | 0.0520 (18) | |
C13 | 0.2564 (14) | 0.7386 (9) | 0.4443 (8) | 0.070 | |
H13A | 0.3999 | 0.7161 | 0.4586 | 0.106* | |
H13B | 0.2293 | 0.7579 | 0.3690 | 0.106* | |
H13C | 0.1705 | 0.6695 | 0.4629 | 0.106* | |
C14 | −0.0195 (13) | 0.8803 (9) | 0.4998 (8) | 0.069 | |
H14A | −0.0975 | 0.8056 | 0.5123 | 0.104* | |
H14B | −0.0583 | 0.9117 | 0.4286 | 0.104* | |
H14C | −0.0483 | 0.9429 | 0.5523 | 0.104* | |
C15 | 0.3316 (15) | 0.9649 (10) | 0.4750 (7) | 0.078 (3) | |
H15A | 0.2943 | 1.0371 | 0.5156 | 0.116* | |
H15B | 0.2992 | 0.9802 | 0.3993 | 0.116* | |
H15C | 0.4777 | 0.9492 | 0.4883 | 0.116* | |
Cl1 | 0.1156 (5) | 0.1156 (2) | 0.7961 (2) | 0.0908 (9) | |
N1 | 0.3167 (7) | 0.7456 (5) | 0.7848 (4) | 0.0336 (11) | |
O2 | 0.6980 (6) | 0.7001 (6) | 0.7256 (4) | 0.0534 (12) | |
H2A | 0.8185 | 0.6858 | 0.7131 | 0.080* | |
O3 | 0.0721 (6) | 0.6749 (5) | 0.6573 (3) | 0.0398 (10) | |
O4 | 0.2916 (7) | 0.8324 (5) | 0.6216 (3) | 0.0448 (11) | |
S1 | 0.4357 (3) | 0.68989 (18) | 0.98363 (12) | 0.0481 (5) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.047 (4) | 0.049 (3) | 0.041 (4) | 0.001 (3) | 0.003 (3) | 0.001 (3) |
C2 | 0.059 (4) | 0.055 (4) | 0.041 (4) | 0.010 (3) | 0.001 (3) | −0.006 (3) |
C3 | 0.064 (4) | 0.047 (4) | 0.053 (4) | −0.006 (3) | −0.014 (3) | 0.007 (3) |
C4 | 0.060 (4) | 0.057 (4) | 0.058 (4) | −0.014 (3) | 0.004 (3) | 0.004 (4) |
C5 | 0.046 (3) | 0.056 (4) | 0.045 (4) | −0.004 (3) | 0.003 (3) | 0.011 (3) |
C6 | 0.039 (3) | 0.035 (3) | 0.031 (3) | 0.000 (2) | 0.002 (2) | 0.008 (3) |
C7 | 0.035 (3) | 0.043 (4) | 0.030 (3) | 0.005 (3) | 0.003 (2) | 0.006 (3) |
C8 | 0.042 (3) | 0.038 (3) | 0.042 (3) | 0.001 (3) | −0.004 (3) | 0.001 (3) |
O1 | 0.060 | 0.060 | 0.060 | 0.000 | 0.005 | 0.000 |
C9 | 0.052 (4) | 0.052 (4) | 0.043 (3) | 0.008 (3) | −0.006 (3) | −0.009 (3) |
C10 | 0.026 (3) | 0.074 (5) | 0.037 (3) | −0.015 (3) | −0.006 (2) | −0.002 (3) |
C11 | 0.028 (3) | 0.053 (4) | 0.031 (3) | 0.009 (3) | −0.002 (2) | −0.002 (3) |
C12 | 0.050 (4) | 0.070 (5) | 0.035 (3) | −0.008 (4) | −0.003 (3) | 0.019 (4) |
C13 | 0.070 | 0.070 | 0.070 | 0.000 | 0.006 | 0.000 |
C14 | 0.070 | 0.070 | 0.070 | 0.000 | 0.006 | 0.000 |
C15 | 0.086 (6) | 0.085 (7) | 0.061 (5) | −0.007 (5) | 0.006 (4) | 0.036 (5) |
Cl1 | 0.115 (2) | 0.0475 (12) | 0.1032 (19) | −0.0122 (13) | −0.0338 (16) | 0.0021 (13) |
N1 | 0.030 (2) | 0.038 (3) | 0.033 (2) | 0.004 (2) | 0.0010 (19) | 0.001 (2) |
O2 | 0.032 (2) | 0.066 (3) | 0.064 (3) | −0.010 (2) | 0.012 (2) | −0.018 (3) |
O3 | 0.029 (2) | 0.058 (3) | 0.0317 (19) | −0.007 (2) | −0.0026 (15) | −0.005 (2) |
O4 | 0.044 (2) | 0.055 (3) | 0.035 (2) | −0.015 (2) | 0.0001 (18) | 0.016 (2) |
S1 | 0.0578 (10) | 0.0564 (10) | 0.0285 (7) | −0.0005 (9) | −0.0071 (6) | −0.0025 (9) |
C1—C6 | 1.379 (9) | C9—H9A | 0.9700 |
C1—C2 | 1.384 (11) | C9—H9B | 0.9700 |
C1—H1 | 0.9300 | C10—O2 | 1.313 (9) |
C2—C3 | 1.367 (11) | C11—O3 | 1.234 (8) |
C2—H2 | 0.9300 | C11—O4 | 1.308 (8) |
C3—C4 | 1.378 (12) | C11—N1 | 1.365 (8) |
C3—Cl1 | 1.744 (8) | C12—O4 | 1.457 (8) |
C4—C5 | 1.390 (11) | C12—C13 | 1.483 (12) |
C4—H4 | 0.9300 | C12—C14 | 1.510 (11) |
C5—C6 | 1.380 (9) | C12—C15 | 1.535 (11) |
C5—H5 | 0.9300 | C13—H13A | 0.9600 |
C6—C7 | 1.490 (9) | C13—H13B | 0.9600 |
C7—N1 | 1.464 (8) | C13—H13C | 0.9600 |
C7—S1 | 1.857 (6) | C14—H14A | 0.9600 |
C7—H7 | 0.9800 | C14—H14B | 0.9600 |
C8—N1 | 1.437 (8) | C14—H14C | 0.9600 |
C8—C10 | 1.510 (9) | C15—H15A | 0.9600 |
C8—C9 | 1.510 (9) | C15—H15B | 0.9600 |
C8—H8 | 0.9800 | C15—H15C | 0.9600 |
O1—C10 | 1.191 (8) | O2—H2A | 0.8200 |
C9—S1 | 1.801 (8) | ||
C6—C1—C2 | 119.0 (7) | O1—C10—O2 | 123.2 (6) |
C6—C1—H1 | 120.5 | O1—C10—C8 | 122.8 (7) |
C2—C1—H1 | 120.5 | O2—C10—C8 | 114.0 (5) |
C3—C2—C1 | 120.9 (7) | O3—C11—O4 | 125.6 (5) |
C3—C2—H2 | 119.6 | O3—C11—N1 | 122.1 (6) |
C1—C2—H2 | 119.6 | O4—C11—N1 | 112.3 (5) |
C2—C3—C4 | 121.4 (8) | O4—C12—C13 | 110.1 (7) |
C2—C3—Cl1 | 119.4 (7) | O4—C12—C14 | 112.7 (6) |
C4—C3—Cl1 | 119.2 (7) | C13—C12—C14 | 111.5 (7) |
C3—C4—C5 | 117.2 (8) | O4—C12—C15 | 102.4 (6) |
C3—C4—H4 | 121.4 | C13—C12—C15 | 110.5 (6) |
C5—C4—H4 | 121.4 | C14—C12—C15 | 109.2 (7) |
C6—C5—C4 | 122.2 (8) | C12—C13—H13A | 109.5 |
C6—C5—H5 | 118.9 | C12—C13—H13B | 109.5 |
C4—C5—H5 | 118.9 | H13A—C13—H13B | 109.5 |
C1—C6—C5 | 119.3 (6) | C12—C13—H13C | 109.5 |
C1—C6—C7 | 122.9 (6) | H13A—C13—H13C | 109.5 |
C5—C6—C7 | 117.8 (6) | H13B—C13—H13C | 109.5 |
N1—C7—C6 | 117.2 (5) | C12—C14—H14A | 109.5 |
N1—C7—S1 | 102.2 (4) | C12—C14—H14B | 109.5 |
C6—C7—S1 | 109.2 (4) | H14A—C14—H14B | 109.5 |
N1—C7—H7 | 109.3 | C12—C14—H14C | 109.5 |
C6—C7—H7 | 109.3 | H14A—C14—H14C | 109.5 |
S1—C7—H7 | 109.3 | H14B—C14—H14C | 109.5 |
N1—C8—C10 | 115.7 (6) | C12—C15—H15A | 109.5 |
N1—C8—C9 | 106.7 (5) | C12—C15—H15B | 109.5 |
C10—C8—C9 | 109.6 (5) | H15A—C15—H15B | 109.5 |
N1—C8—H8 | 108.2 | C12—C15—H15C | 109.5 |
C10—C8—H8 | 108.2 | H15A—C15—H15C | 109.5 |
C9—C8—H8 | 108.2 | H15B—C15—H15C | 109.5 |
C8—C9—S1 | 104.3 (5) | C11—N1—C8 | 121.3 (5) |
C8—C9—H9A | 110.9 | C11—N1—C7 | 119.6 (5) |
S1—C9—H9A | 110.9 | C8—N1—C7 | 118.1 (5) |
C8—C9—H9B | 110.9 | C10—O2—H2A | 109.5 |
S1—C9—H9B | 110.9 | C11—O4—C12 | 121.8 (5) |
H9A—C9—H9B | 108.9 | C9—S1—C7 | 90.0 (3) |
C6—C1—C2—C3 | −2.5 (11) | O3—C11—N1—C8 | −176.7 (6) |
C1—C2—C3—C4 | 2.1 (12) | O4—C11—N1—C8 | 3.6 (8) |
C1—C2—C3—Cl1 | −178.8 (6) | O3—C11—N1—C7 | −8.1 (9) |
C2—C3—C4—C5 | −1.1 (11) | O4—C11—N1—C7 | 172.2 (5) |
Cl1—C3—C4—C5 | 179.8 (6) | C10—C8—N1—C11 | −83.3 (7) |
C3—C4—C5—C6 | 0.5 (11) | C9—C8—N1—C11 | 154.5 (5) |
C2—C1—C6—C5 | 1.9 (10) | C10—C8—N1—C7 | 107.9 (6) |
C2—C1—C6—C7 | 178.9 (6) | C9—C8—N1—C7 | −14.2 (7) |
C4—C5—C6—C1 | −0.9 (10) | C6—C7—N1—C11 | 56.7 (7) |
C4—C5—C6—C7 | −178.1 (6) | S1—C7—N1—C11 | 176.0 (4) |
C1—C6—C7—N1 | 42.7 (8) | C6—C7—N1—C8 | −134.4 (6) |
C5—C6—C7—N1 | −140.2 (6) | S1—C7—N1—C8 | −15.1 (6) |
C1—C6—C7—S1 | −72.7 (7) | O3—C11—O4—C12 | −0.4 (10) |
C5—C6—C7—S1 | 104.3 (6) | N1—C11—O4—C12 | 179.3 (6) |
N1—C8—C9—S1 | 37.6 (6) | C13—C12—O4—C11 | −67.2 (8) |
C10—C8—C9—S1 | −88.4 (6) | C14—C12—O4—C11 | 58.1 (10) |
N1—C8—C10—O1 | −174.4 (6) | C15—C12—O4—C11 | 175.3 (6) |
C9—C8—C10—O1 | −53.8 (9) | C8—C9—S1—C7 | −40.6 (5) |
N1—C8—C10—O2 | 3.4 (8) | N1—C7—S1—C9 | 31.7 (4) |
C9—C8—C10—O2 | 124.0 (6) | C6—C7—S1—C9 | 156.5 (5) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2A···O3i | 0.82 | 1.83 | 2.638 (6) | 167 |
Symmetry code: (i) x+1, y, z. |
Experimental details
Crystal data | |
Chemical formula | C15H18ClNO4S |
Mr | 343.81 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 293 |
a, b, c (Å) | 6.4600 (13), 10.641 (2), 12.411 (3) |
β (°) | 94.52 (3) |
V (Å3) | 850.5 (3) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.36 |
Crystal size (mm) | 0.30 × 0.20 × 0.10 |
Data collection | |
Diffractometer | Enraf–Nonius CAD-4 diffractometer |
Absorption correction | ψ scan (North et al., 1968) |
Tmin, Tmax | 0.899, 0.965 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 1638, 1638, 1363 |
Rint | 0.000 |
(sin θ/λ)max (Å−1) | 0.600 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.062, 0.159, 1.08 |
No. of reflections | 1638 |
No. of parameters | 185 |
No. of restraints | 89 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.43, −0.37 |
Absolute structure | Flack (1983) |
Absolute structure parameter | −0.09 (19) |
Computer programs: CAD-4 Software (Enraf–Nonius, 1989), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2A···O3i | 0.82 | 1.83 | 2.638 (6) | 167 |
Symmetry code: (i) x+1, y, z. |
Acknowledgements
The work was supported by youthfund project (project JQ201006) of Changzhou University.
References
Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. CrossRef Web of Science Google Scholar
Enraf–Nonius (1989). CAD-4 Software. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
Lu, Y., Wang, Z., Li, C.-M., Chen, J.-J., Dalton, J. T., Li, W. & Miller, D. D. (2010). Bioorg. Med. Chem. 18, 477–495. Web of Science CrossRef CAS PubMed Google Scholar
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359. CrossRef IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Song, Z.-C., Ma, G.-Y., Lv, P.-C., Li, H.-Q., Xiao, Z.-P. & Zhu, H.-L. (2009). Eur. J. Med. Chem. 44, 3903–3908. Web of Science CSD CrossRef PubMed CAS Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Recently, 3-tert-butoxycarbonyl-2-arylthiazolidine-4-carboxylic acid derivatives have been reported to possess antimicrobial and antitumor activities (Song et al., 2009; Lu et al., 2010). In this work, we report here the crystal structure of the title compound, (I). In (I), all bond lengths are within normal ranges (Allen et al., 1987) (Fig. 1). There are intermolecular O—H···O hydrogen bonds in (I).