Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807045308/gg2023sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807045308/gg2023Isup2.hkl |
CCDC reference: 663822
Key indicators
- Single-crystal X-ray study
- T = 150 K
- Mean (C-C) = 0.003 Å
- R factor = 0.036
- wR factor = 0.069
- Data-to-parameter ratio = 8.0
checkCIF/PLATON results
No syntax errors found
Alert level C PLAT222_ALERT_3_C Large Non-Solvent H Ueq(max)/Ueq(min) ... 3.99 Ratio PLAT720_ALERT_4_C Number of Unusual/Non-Standard Label(s) ........ 8
Alert level G REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is correct. If it is not, please give the correct count in the _publ_section_exptl_refinement section of the submitted CIF. From the CIF: _diffrn_reflns_theta_max 26.02 From the CIF: _reflns_number_total 1737 Count of symmetry unique reflns 1738 Completeness (_total/calc) 99.94% TEST3: Check Friedels for noncentro structure Estimate of Friedel pairs measured 0 Fraction of Friedel pairs measured 0.000 Are heavy atom types Z>Si present no PLAT791_ALERT_1_G Confirm the Absolute Configuration of C1' = . S PLAT791_ALERT_1_G Confirm the Absolute Configuration of C3 = . R PLAT791_ALERT_1_G Confirm the Absolute Configuration of C3' = . S PLAT860_ALERT_3_G Note: Number of Least-Squares Restraints ....... 2
0 ALERT level A = In general: serious problem 0 ALERT level B = Potentially serious problem 2 ALERT level C = Check and explain 5 ALERT level G = General alerts; check 3 ALERT type 1 CIF construction/syntax error, inconsistent or missing data 0 ALERT type 2 Indicator that the structure model may be wrong or deficient 2 ALERT type 3 Indicator that the structure quality may be low 2 ALERT type 4 Improvement, methodology, query or suggestion 0 ALERT type 5 Informative message, check
The reaction has been described in the preceeding paper (Urban et al., 2007). At least two products were produced by the reaction. Column chromatography afforded 256 mg of the title compound (I), 150 mg after its recrystallization from CHCl3:n–C6H14.
In the absence of significant anomalous scattering effects 1249 Friedel pairs have been merged (Rint = 0.022). All of the H atoms could be discerned in the difference Fourier maps, nevertheless, all of the H attached to the C atoms were constrained in a riding motion approximation while the hydroxyl H atoms were restrained (0.820 (1) Å) and their isotropic displacement parameters were freely refined, Caryl—H = 0.93, Cmethylene—H = 0.97, Cmethine—H = 0.98 Å while UisoH = 1.2UeqC. The absolute configuration has not been determined.
Our research project deals with chemical and electrochemical properties of diketones (Zuman, 2004). As a part of this study, we have observed that a main product of the reaction of orthophthalaldehyde with amines in low concentrations about 10 -3 mol/l is reducible about 0.5 V more negatively than the parent dialdehyde. In order to study this reaction as well as in order to identify the product (isoindoline derivative is expected to be formed) the reaction of phthalaldehyde with kolamine (2-aminoethanol) was performed.
In ethanol, however, the reaction results in a mixture of non-separable, viscous, probably polymeric compounds. On the other hand, the reaction in acetonitrile leads to two minor products together with formation of a non-separable mixture. The minor products were isolated, purified, crystallized and analyzed by NMR and single-crystal X-ray diffraction.
One of these compounds was identified as 2-(2''-hydroxyethyl)-3-(3'-hydroxy-1'H,3'H-benzo[c]furan-1'-yl-1H,3H- benzo[c]pyrrol-1-one (here reported as a title structure) while the second compound was characterized as 2-(2-hydroxyethyl)-1H,3H benzo[c]pyrrol-1-one (Urban et al., 2007) as described in the preceeding article.
For more details, see Urban et al. (2007).
Two kinds of the O—H···O hydrogen bonds bind the title molecules into layers parallel to (001). The graph set motifs are C11(9) and C11(10) for the O1···O3 and O4···O3 hydrogen bonds, respectively.
The atoms in the five-membered ring N2–C1–C7a–C4a–C3 (substituted pyrrole) form a fair plane with a maximal deviation of C4a from the mean plane that is 0.010 (2) Å. On the other hand, the atoms in the five-membered ring O2'–C3'–C4'a–C7'a–C1' (substituted furan) are situated approximately in the plane with a maximal deviation from the mean plane for C3' that is 0.082 (3) Å.
The dihedral angle between the pyrrole and the attached phenyl ring is 1.19 (8)° while the dihedral angle between the substituted furan and the attached phenyl ring is 6.97 (8)°. These values also indicate a lesser aromaticity of the isobenzofuran ring in comparison with the isoindoline ring.
There is also a short π–π electron interaction between the aromatic rings O2'–C3'–C4'a–C7'a–C1' and N2–C1–C7a–C4a–C3 as indicates the distance between the respective centroids being 3.3172 (13) Å.
Many isoindoline derivatives display biological as well as pharmaceutical activity (Mukherjee et al., 2000).
For the structure of a closely related compound isolated from the same reaction, see: Urban et al. (2007). For related literature, see: Becker & Coppens (1974); Zuman (2004). For an article on the biological activity of isoindolines, see: Mukherjee et al. (2000).
Data collection: COLLECT (Nonius, 1998) and DENZO (Otwinowski & Minor, 1997); cell refinement: COLLECT (Nonius, 1998) and DENZO (Otwinowski & Minor, 1997); data reduction: COLLECT (Nonius, 1998) and DENZO (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: JANA2000 (Petříček et al., 2000); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: JANA2000 (Petříček et al., 2000).
Fig. 1. The molecules of the title structure (I) with displacement parameters shown at 50% probability level. | |
Fig. 2. A view of the title structure (I) with O—H···O hydrogen bonds. |
C18H17NO4 | F(000) = 656 |
Mr = 311.3 | Dx = 1.363 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 1756 reflections |
a = 7.0292 (1) Å | θ = 1–26.0° |
b = 11.9861 (5) Å | µ = 0.10 mm−1 |
c = 18.0014 (7) Å | T = 150 K |
V = 1516.67 (9) Å3 | Prism, colourless |
Z = 4 | 0.2 × 0.08 × 0.05 mm |
Nonius KappaCCD area-detector diffractometer | 1482 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.058 |
Graphite monochromator | θmax = 26.0°, θmin = 2.0° |
Detector resolution: 9.091 pixels mm-1 | h = −8→8 |
φ and ω scans | k = −14→14 |
18223 measured reflections | l = −22→22 |
1737 independent reflections |
Refinement on F2 | H atoms treated by a mixture of independent and constrained refinement |
R[F > 3σ(F)] = 0.037 | Weighting scheme based on measured s.u.'s w = 1/(σ2(I) + 0.0004I2) |
wR(F) = 0.069 | (Δ/σ)max = 0.006 |
S = 1.65 | Δρmax = 0.16 e Å−3 |
1737 reflections | Δρmin = −0.17 e Å−3 |
217 parameters | Extinction correction: B-C type 1 Lorentzian isotropic (Becker & Coppens, 1974) |
2 restraints | Extinction coefficient: 1.57 (16) |
60 constraints |
C18H17NO4 | V = 1516.67 (9) Å3 |
Mr = 311.3 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 7.0292 (1) Å | µ = 0.10 mm−1 |
b = 11.9861 (5) Å | T = 150 K |
c = 18.0014 (7) Å | 0.2 × 0.08 × 0.05 mm |
Nonius KappaCCD area-detector diffractometer | 1482 reflections with I > 2σ(I) |
18223 measured reflections | Rint = 0.058 |
1737 independent reflections |
R[F > 3σ(F)] = 0.037 | 2 restraints |
wR(F) = 0.069 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.65 | Δρmax = 0.16 e Å−3 |
1737 reflections | Δρmin = −0.17 e Å−3 |
217 parameters |
x | y | z | Uiso*/Ueq | ||
C1 | 0.6319 (3) | 0.35574 (19) | 0.31944 (13) | 0.0247 (7) | |
O1 | 0.4921 (2) | 0.36611 (15) | 0.36055 (9) | 0.0344 (6) | |
N2 | 0.7803 (2) | 0.28509 (16) | 0.33170 (10) | 0.0228 (6) | |
C3 | 0.9250 (3) | 0.28969 (18) | 0.27316 (12) | 0.0223 (7) | |
H3 | 1.049523 | 0.313389 | 0.291876 | 0.0268* | |
C4a | 0.8429 (3) | 0.37409 (19) | 0.22012 (12) | 0.0229 (7) | |
C7a | 0.6721 (3) | 0.41363 (19) | 0.24872 (13) | 0.0243 (7) | |
C4 | 0.9105 (3) | 0.41434 (19) | 0.15273 (12) | 0.0254 (8) | |
H4 | 1.025186 | 0.389264 | 0.133152 | 0.0305* | |
C5 | 0.8021 (3) | 0.49305 (18) | 0.11539 (13) | 0.0286 (8) | |
H5 | 0.843911 | 0.519653 | 0.069689 | 0.0344* | |
C6 | 0.6330 (3) | 0.5332 (2) | 0.14428 (13) | 0.0304 (8) | |
H6 | 0.564561 | 0.58684 | 0.118234 | 0.0364* | |
C7 | 0.5651 (3) | 0.49403 (19) | 0.21169 (13) | 0.0300 (8) | |
H7 | 0.451645 | 0.520785 | 0.231403 | 0.036* | |
O2' | 0.8001 (2) | 0.13188 (13) | 0.20416 (8) | 0.0284 (5) | |
C3' | 0.8425 (3) | 0.09010 (18) | 0.13168 (13) | 0.0256 (7) | |
H3' | 0.742632 | 0.110399 | 0.096186 | 0.0307* | |
C4'a | 1.0382 (3) | 0.13391 (19) | 0.11551 (12) | 0.0221 (7) | |
C7'a | 1.1135 (3) | 0.18025 (19) | 0.17942 (13) | 0.0222 (7) | |
C1' | 0.9675 (3) | 0.17481 (19) | 0.23995 (12) | 0.0239 (7) | |
H1' | 1.008275 | 0.125368 | 0.280284 | 0.0286* | |
C4' | 1.1405 (3) | 0.13336 (19) | 0.04959 (13) | 0.0297 (8) | |
H4' | 1.091314 | 0.100496 | 0.006917 | 0.0356* | |
C5' | 1.3188 (3) | 0.18345 (19) | 0.04942 (14) | 0.0322 (8) | |
H5' | 1.388937 | 0.18607 | 0.005654 | 0.0387* | |
C6' | 1.3937 (3) | 0.2297 (2) | 0.11368 (14) | 0.0310 (8) | |
H6' | 1.513096 | 0.262987 | 0.112345 | 0.0372* | |
C7' | 1.2934 (3) | 0.22706 (19) | 0.17991 (14) | 0.0271 (8) | |
H7' | 1.345299 | 0.255859 | 0.223395 | 0.0325* | |
O3 | 0.8433 (2) | −0.02678 (14) | 0.13010 (10) | 0.0316 (6) | |
H3O | 0.737 (2) | −0.055 (3) | 0.131 (2) | 0.107 (14)* | |
C1'' | 0.7943 (3) | 0.21383 (19) | 0.39678 (12) | 0.0254 (7) | |
H1''a | 0.675818 | 0.216763 | 0.424362 | 0.0304* | |
H1''b | 0.807196 | 0.136731 | 0.381209 | 0.0304* | |
C2'' | 0.9573 (3) | 0.24420 (19) | 0.44749 (13) | 0.0278 (8) | |
H2''a | 0.963299 | 0.191412 | 0.488262 | 0.0334* | |
H2''b | 1.076237 | 0.238248 | 0.420462 | 0.0334* | |
O4 | 0.9379 (3) | 0.35389 (15) | 0.47616 (10) | 0.0349 (6) | |
H4O | 0.993 (4) | 0.395 (2) | 0.4465 (14) | 0.086 (14)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0259 (12) | 0.0258 (14) | 0.0224 (13) | −0.0003 (11) | 0.0000 (11) | −0.0029 (11) |
O1 | 0.0323 (9) | 0.0402 (11) | 0.0308 (10) | 0.0089 (8) | 0.0089 (8) | 0.0042 (9) |
N2 | 0.0266 (10) | 0.0256 (11) | 0.0162 (10) | 0.0031 (8) | 0.0011 (8) | 0.0006 (9) |
C3 | 0.0205 (11) | 0.0269 (13) | 0.0195 (13) | 0.0011 (10) | 0.0018 (9) | 0.0005 (11) |
C4a | 0.0270 (11) | 0.0219 (12) | 0.0199 (12) | −0.0033 (10) | −0.0029 (10) | −0.0029 (11) |
C7a | 0.0284 (11) | 0.0223 (12) | 0.0222 (13) | −0.0014 (10) | −0.0027 (10) | −0.0026 (10) |
C4 | 0.0291 (12) | 0.0221 (13) | 0.0249 (14) | −0.0007 (10) | 0.0011 (10) | −0.0029 (11) |
C5 | 0.0361 (14) | 0.0242 (14) | 0.0256 (14) | −0.0039 (11) | −0.0021 (11) | 0.0011 (11) |
C6 | 0.0363 (13) | 0.0262 (14) | 0.0286 (14) | 0.0022 (11) | −0.0081 (11) | 0.0025 (12) |
C7 | 0.0305 (13) | 0.0300 (14) | 0.0295 (14) | 0.0066 (12) | −0.0029 (11) | −0.0018 (12) |
O2' | 0.0248 (8) | 0.0306 (9) | 0.0298 (10) | −0.0061 (7) | 0.0054 (7) | −0.0079 (8) |
C3' | 0.0273 (12) | 0.0239 (13) | 0.0254 (14) | 0.0016 (10) | 0.0045 (11) | −0.0027 (11) |
C4'a | 0.0227 (11) | 0.0196 (12) | 0.0241 (13) | 0.0025 (10) | 0.0008 (10) | 0.0006 (11) |
C7'a | 0.0220 (11) | 0.0210 (13) | 0.0237 (13) | 0.0045 (9) | 0.0020 (10) | 0.0023 (10) |
C1' | 0.0228 (11) | 0.0266 (13) | 0.0222 (13) | 0.0004 (10) | −0.0006 (10) | −0.0005 (11) |
C4' | 0.0347 (13) | 0.0268 (13) | 0.0276 (14) | −0.0003 (11) | 0.0019 (11) | −0.0014 (12) |
C5' | 0.0311 (12) | 0.0331 (14) | 0.0324 (15) | −0.0028 (12) | 0.0122 (12) | −0.0018 (13) |
C6' | 0.0229 (11) | 0.0315 (15) | 0.0387 (16) | −0.0015 (10) | 0.0053 (11) | −0.0001 (12) |
C7' | 0.0225 (11) | 0.0291 (15) | 0.0296 (15) | 0.0002 (10) | −0.0011 (11) | −0.0019 (12) |
O3 | 0.0296 (9) | 0.0230 (10) | 0.0422 (11) | −0.0031 (7) | 0.0046 (8) | −0.0034 (8) |
C1'' | 0.0302 (12) | 0.0264 (14) | 0.0195 (13) | 0.0006 (10) | 0.0033 (10) | 0.0022 (11) |
C2'' | 0.0356 (13) | 0.0255 (13) | 0.0224 (13) | −0.0007 (11) | −0.0002 (11) | 0.0017 (11) |
O4 | 0.0498 (10) | 0.0271 (11) | 0.0279 (11) | −0.0029 (9) | 0.0007 (8) | −0.0038 (9) |
C1—O1 | 1.237 (3) | C5'—C6' | 1.387 (3) |
C1—N2 | 1.362 (3) | C6'—C7' | 1.385 (3) |
C1—C7a | 1.477 (3) | C1''—C2'' | 1.510 (3) |
N2—C3 | 1.466 (3) | C2''—O4 | 1.419 (3) |
N2—C1'' | 1.453 (3) | C3—H3 | 0.98 |
C3—C4a | 1.506 (3) | C4—H4 | 0.93 |
C3—C1' | 1.531 (3) | C5—H5 | 0.93 |
C4a—C7a | 1.390 (3) | C6—H6 | 0.93 |
C4a—C4 | 1.389 (3) | C7—H7 | 0.93 |
C7a—C7 | 1.392 (3) | C3'—H3' | 0.98 |
C4—C5 | 1.387 (3) | C1'—H1' | 0.98 |
C5—C6 | 1.384 (3) | C4'—H4' | 0.93 |
C6—C7 | 1.386 (3) | C5'—H5' | 0.93 |
O2'—C3' | 1.429 (3) | C6'—H6' | 0.93 |
O2'—C1' | 1.437 (3) | C7'—H7' | 0.93 |
C3'—C4'a | 1.501 (3) | O3—H3O | 0.82 (2) |
C3'—O3 | 1.401 (3) | C1''—H1''a | 0.97 |
C4'a—C7'a | 1.383 (3) | C1''—H1''b | 0.97 |
C4'a—C4' | 1.388 (3) | C2''—H2''a | 0.97 |
C7'a—C1' | 1.499 (3) | C2''—H2''b | 0.97 |
C7'a—C7' | 1.383 (3) | O4—H4O | 0.82 (3) |
C4'—C5' | 1.389 (3) | ||
O1—C1—N2 | 125.1 (2) | O2'—C3'—C4'a | 104.22 (17) |
O1—C1—C7a | 128.4 (2) | O2'—C3'—O3 | 111.69 (18) |
N2—C1—C7a | 106.57 (18) | C4'a—C3'—O3 | 110.02 (18) |
C1—N2—C3 | 113.06 (18) | C3'—C4'a—C7'a | 109.29 (19) |
C1—N2—C1'' | 123.23 (18) | C3'—C4'a—C4' | 129.7 (2) |
C3—N2—C1'' | 123.70 (17) | C7'a—C4'a—C4' | 120.97 (19) |
N2—C3—C4a | 102.43 (16) | C4'a—C7'a—C1' | 108.97 (17) |
N2—C3—C1' | 112.48 (17) | C4'a—C7'a—C7' | 121.2 (2) |
C4a—C3—C1' | 115.56 (18) | C1'—C7'a—C7' | 129.7 (2) |
C3—C4a—C7a | 108.98 (18) | C3—C1'—O2' | 109.73 (16) |
C3—C4a—C4 | 130.99 (19) | C3—C1'—C7'a | 112.24 (18) |
C7a—C4a—C4 | 120.0 (2) | O2'—C1'—C7'a | 104.50 (17) |
C1—C7a—C4a | 108.93 (19) | C4'a—C4'—C5' | 117.9 (2) |
C1—C7a—C7 | 129.4 (2) | C4'—C5'—C6' | 120.9 (2) |
C4a—C7a—C7 | 121.7 (2) | C5'—C6'—C7' | 121.1 (2) |
C4a—C4—C5 | 118.2 (2) | C7'a—C7'—C6' | 117.9 (2) |
C4—C5—C6 | 121.8 (2) | N2—C1''—C2'' | 113.39 (18) |
C5—C6—C7 | 120.5 (2) | C1''—C2''—O4 | 111.75 (19) |
C7a—C7—C6 | 117.9 (2) | H1''a—C1''—H1''b | 105.2 |
C3'—O2'—C1' | 111.36 (15) | H2''a—C2''—H2''b | 107.1 |
Experimental details
Crystal data | |
Chemical formula | C18H17NO4 |
Mr | 311.3 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 150 |
a, b, c (Å) | 7.0292 (1), 11.9861 (5), 18.0014 (7) |
V (Å3) | 1516.67 (9) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.2 × 0.08 × 0.05 |
Data collection | |
Diffractometer | Nonius KappaCCD area-detector |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 18223, 1737, 1482 |
Rint | 0.058 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F > 3σ(F)], wR(F), S | 0.037, 0.069, 1.65 |
No. of reflections | 1737 |
No. of parameters | 217 |
No. of restraints | 2 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.16, −0.17 |
Computer programs: COLLECT (Nonius, 1998) and DENZO (Otwinowski & Minor, 1997), SIR97 (Altomare et al., 1999), JANA2000 (Petříček et al., 2000), PLATON (Spek, 2003).
D—H···A/Cg | D—H | H···A/Cg | D···A/Cg | D—H···A/Cg |
O4-H4O···O3 | 0.82 (2) | 2.03 (2) | 2.841 (2) | 170 (2) |
O3-H3O···O1 | 0.82 (2) | 1.87 (2) | 2.690 (2) | 172 (2) |
C1''-H1''a···O1 | 0.97 | 2.49 | 2.876 (2) | 104 |
C1''-H1''a···O4 | 0.97 | 2.59 | 3.488 (3) | 154 |
C3-H3···O3 | 0.98 | 2.49 | 3.244 (2) | 133 |
C7-H7···O2' | 0.93 | 2.50 | 3.408 (2) | 165 |
C4-H4···Cg1 | 0.93 | 2.85 | 3.591 (2) | 137 |
C1'-H1'···Cg2v | 0.98 | 2.81 | 3.645 (2) | 144 |
Symmetry codes: (i) -x+2, y+1/2, -z+1/2; (ii) -x+1, y-1/2, 1/2-z; (iii) x-1/2, 1/2-y, 1-z; (iv) -x+1, y+1/2, 1/2-z; (v) -x, y-1/2, 1/2-z. |
Our research project deals with chemical and electrochemical properties of diketones (Zuman, 2004). As a part of this study, we have observed that a main product of the reaction of orthophthalaldehyde with amines in low concentrations about 10 -3 mol/l is reducible about 0.5 V more negatively than the parent dialdehyde. In order to study this reaction as well as in order to identify the product (isoindoline derivative is expected to be formed) the reaction of phthalaldehyde with kolamine (2-aminoethanol) was performed.
In ethanol, however, the reaction results in a mixture of non-separable, viscous, probably polymeric compounds. On the other hand, the reaction in acetonitrile leads to two minor products together with formation of a non-separable mixture. The minor products were isolated, purified, crystallized and analyzed by NMR and single-crystal X-ray diffraction.
One of these compounds was identified as 2-(2''-hydroxyethyl)-3-(3'-hydroxy-1'H,3'H-benzo[c]furan-1'-yl-1H,3H- benzo[c]pyrrol-1-one (here reported as a title structure) while the second compound was characterized as 2-(2-hydroxyethyl)-1H,3H benzo[c]pyrrol-1-one (Urban et al., 2007) as described in the preceeding article.
For more details, see Urban et al. (2007).
Two kinds of the O—H···O hydrogen bonds bind the title molecules into layers parallel to (001). The graph set motifs are C11(9) and C11(10) for the O1···O3 and O4···O3 hydrogen bonds, respectively.
The atoms in the five-membered ring N2–C1–C7a–C4a–C3 (substituted pyrrole) form a fair plane with a maximal deviation of C4a from the mean plane that is 0.010 (2) Å. On the other hand, the atoms in the five-membered ring O2'–C3'–C4'a–C7'a–C1' (substituted furan) are situated approximately in the plane with a maximal deviation from the mean plane for C3' that is 0.082 (3) Å.
The dihedral angle between the pyrrole and the attached phenyl ring is 1.19 (8)° while the dihedral angle between the substituted furan and the attached phenyl ring is 6.97 (8)°. These values also indicate a lesser aromaticity of the isobenzofuran ring in comparison with the isoindoline ring.
There is also a short π–π electron interaction between the aromatic rings O2'–C3'–C4'a–C7'a–C1' and N2–C1–C7a–C4a–C3 as indicates the distance between the respective centroids being 3.3172 (13) Å.
Many isoindoline derivatives display biological as well as pharmaceutical activity (Mukherjee et al., 2000).