Supporting information
Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536807026785/bh2108sup1.cif | |
Structure factor file (CIF format) https://doi.org/10.1107/S1600536807026785/bh2108Isup2.hkl |
CCDC reference: 655602
To a well stirred solution of N-cyclohexyl-2-nitrobenzenesulfonamide (5.68 g, 0.02 mol) in 20 ml of dry THF was added 50% NaH (1.44 g, 0.03 mol) slowly. After 1 h under stirring, a solution of ethyl oxalyl chloride (2.73 g, 0.02 mol) in 5 ml of dry THF was dropwise added and the mixture further stirred at 313–323 K for 3 h. After removing the solvent, water was added (20 ml), and the mixture was extracted with ethyl acetate and dried over magnesium sulfate. The ester was removed and the residue was purified by chromatography over silica gel with petroleum ether/ethyl acetate as eluent (9:1), affording (I). Yield: 87%; m.p. 391–392 K. 1H NMR (CDCl3) δ: 8.34–7.75 (m, 4H, Ph—H), 4.36 (q, J=7.20 Hz, 2H, CH2), 3.88–3.78 (m, 1H, cyclohexyl-CH), 1.37 (t, J=7.20 Hz, 3H, CH3), 2.23–1.11 (m, 10H, cyclohexyl-CH2). Anal. Calcd. for C16H20N2O7S: C 49.99, H 5.24, N 7.29%. Found: C 50.13, H 5.31, N 7.61%. Colourless single crystals suitable for X-ray diffraction analysis were obtained by recrystallization from petroleum ether and ethyl acetate (1:1).
H atoms were placed in idealized positions and constrained to ride on their parent atoms, with C—H distances of 0.93 (aromatic CH), 0.96 (methyl CH3), 0.97 (methylene CH2) or 0.98 Å (methine CH), and with Uiso(H) = 1.5Ueq(carrier C atom) for methyl group and Uiso(H) = 1.2Ueq(carrier C atom) for other H atoms.
Inhibitors of KARI (ketol-acid reductoisomerase) have been synthesized and tested as herbicides. 2-Dimethylphosphinoyl-2-hydroxy acetic acid (Hoe 704, Schulz et al., 1988), N-hydroxy-N-isopropyloxamate (IpOHA, Aulabaugh et al., 1990) and cyclopropane-1,1-dicarboxylate (CPD, Lee et al., 2005) are potent inhibitors of the enzyme in vitro but their activity as herbicides are weak. There are few reports about the design, synthesis and biological activity of new KARI inhibitors. Nevertheless, inhibitors of KARI remain a potential source for finding novel herbicidal compounds (Wang et al., 2005). With this in mind, a series of ethyl-2-(N-substituted-arylsulfonamido)-2-oxoacetate compounds has been designed and synthesized, based on the structure of KARI inhibitor IpOHA. The X-ray crystal structure determination of the title compound, (I), was undertaken in order to investigate the relationship between structure and herbicidal activity.
The X-ray analysis reveals that in the title compound, the cyclohexane ring is in a chair conformation and is bonded to the amine N atom (Fig. 1). Two C═ O groups are trans arranged, with the torsion angle O5—C13—C14—O6 being -114.0 (5)°. The dihedral angle between the tertiary amine plane (S1/C7/C13/N2) and ethoxylcarbonyl O—C═O group (O6/O7/O14) is 75.1 (2)°. The dihedral angle between the amine plane and benzene ring C1···C6 is 74.0 (2)°.
For related reports, see: Schulz et al. (1988); Aulabaugh & Schloss (1990); Lee et al. (2005); Wang et al. (2005).
Data collection: SMART (Bruker, 1998); cell refinement: SAINT (Bruker, 1998); 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, 1998); software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).
Fig. 1. The molecular structure of (I). Displacement ellipsoids are drawn at the 20% probability level. |
C16H20N2O7S | F(000) = 808 |
Mr = 384.40 | Dx = 1.388 Mg m−3 |
Monoclinic, P21/n | Melting point = 391–392 K |
Hall symbol: -P 2yn | Mo Kα radiation, λ = 0.71073 Å |
a = 10.962 (7) Å | Cell parameters from 1731 reflections |
b = 12.352 (7) Å | θ = 2.2–21.7° |
c = 13.879 (8) Å | µ = 0.22 mm−1 |
β = 101.813 (11)° | T = 294 K |
V = 1839.5 (19) Å3 | Block, colourless |
Z = 4 | 0.24 × 0.22 × 0.20 mm |
Bruker SMART 1000 CCD area-detector diffractometer | 3240 independent reflections |
Radiation source: fine-focus sealed tube | 1813 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.074 |
φ and ω scans | θmax = 25.0°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | h = −13→11 |
Tmin = 0.896, Tmax = 0.960 | k = −14→12 |
9177 measured reflections | l = −16→16 |
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)] = 0.047 | H-atom parameters constrained |
wR(F2) = 0.129 | w = 1/[σ2(Fo2) + (0.0538P)2] where P = (Fo2 + 2Fc2)/3 |
S = 1.01 | (Δ/σ)max = 0.001 |
3240 reflections | Δρmax = 0.23 e Å−3 |
237 parameters | Δρmin = −0.26 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.029 (2) |
C16H20N2O7S | V = 1839.5 (19) Å3 |
Mr = 384.40 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 10.962 (7) Å | µ = 0.22 mm−1 |
b = 12.352 (7) Å | T = 294 K |
c = 13.879 (8) Å | 0.24 × 0.22 × 0.20 mm |
β = 101.813 (11)° |
Bruker SMART 1000 CCD area-detector diffractometer | 3240 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 1998) | 1813 reflections with I > 2σ(I) |
Tmin = 0.896, Tmax = 0.960 | Rint = 0.074 |
9177 measured reflections |
R[F2 > 2σ(F2)] = 0.047 | 0 restraints |
wR(F2) = 0.129 | H-atom parameters constrained |
S = 1.01 | Δρmax = 0.23 e Å−3 |
3240 reflections | Δρmin = −0.26 e Å−3 |
237 parameters |
x | y | z | Uiso*/Ueq | ||
S1 | 0.30775 (8) | 0.54366 (6) | 0.13647 (6) | 0.0434 (3) | |
O1 | −0.0287 (3) | 0.6633 (2) | 0.0056 (2) | 0.0895 (10) | |
O2 | 0.1287 (3) | 0.7293 (2) | 0.10732 (18) | 0.0711 (8) | |
O3 | 0.2700 (2) | 0.56089 (16) | 0.03315 (15) | 0.0525 (6) | |
O4 | 0.3794 (2) | 0.62380 (16) | 0.19704 (17) | 0.0578 (7) | |
O5 | 0.5814 (3) | 0.3564 (2) | 0.2134 (2) | 0.1016 (11) | |
O6 | 0.4471 (3) | 0.4822 (2) | 0.36867 (19) | 0.0739 (8) | |
O7 | 0.6185 (2) | 0.55085 (19) | 0.32483 (16) | 0.0622 (7) | |
N1 | 0.0524 (3) | 0.6590 (2) | 0.0797 (2) | 0.0554 (8) | |
N2 | 0.3898 (2) | 0.42994 (18) | 0.15192 (18) | 0.0429 (7) | |
C1 | 0.0573 (3) | 0.5618 (2) | 0.1426 (2) | 0.0444 (8) | |
C2 | −0.0531 (3) | 0.5281 (3) | 0.1653 (3) | 0.0630 (10) | |
H2 | −0.1273 | 0.5634 | 0.1389 | 0.076* | |
C3 | −0.0524 (4) | 0.4413 (3) | 0.2278 (3) | 0.0704 (11) | |
H3 | −0.1263 | 0.4173 | 0.2438 | 0.085* | |
C4 | 0.0586 (4) | 0.3903 (3) | 0.2665 (3) | 0.0645 (11) | |
H4 | 0.0592 | 0.3324 | 0.3094 | 0.077* | |
C5 | 0.1687 (3) | 0.4233 (2) | 0.2427 (2) | 0.0494 (9) | |
H5 | 0.2425 | 0.3874 | 0.2694 | 0.059* | |
C6 | 0.1703 (3) | 0.5101 (2) | 0.1792 (2) | 0.0396 (8) | |
C7 | 0.3473 (3) | 0.3418 (2) | 0.0781 (2) | 0.0423 (8) | |
H7 | 0.2593 | 0.3564 | 0.0502 | 0.051* | |
C8 | 0.4136 (3) | 0.3436 (3) | −0.0075 (2) | 0.0556 (10) | |
H8A | 0.5012 | 0.3272 | 0.0158 | 0.067* | |
H8B | 0.4072 | 0.4152 | −0.0368 | 0.067* | |
C9 | 0.3552 (3) | 0.2602 (3) | −0.0844 (2) | 0.0618 (11) | |
H9A | 0.2698 | 0.2809 | −0.1121 | 0.074* | |
H9B | 0.4008 | 0.2591 | −0.1374 | 0.074* | |
C10 | 0.3567 (4) | 0.1474 (3) | −0.0398 (3) | 0.0631 (11) | |
H10A | 0.3144 | 0.0972 | −0.0892 | 0.076* | |
H10B | 0.4422 | 0.1232 | −0.0186 | 0.076* | |
C11 | 0.2935 (4) | 0.1475 (3) | 0.0467 (3) | 0.0668 (11) | |
H11A | 0.2993 | 0.0757 | 0.0757 | 0.080* | |
H11B | 0.2059 | 0.1644 | 0.0241 | 0.080* | |
C12 | 0.3517 (4) | 0.2296 (3) | 0.1251 (2) | 0.0613 (10) | |
H12A | 0.4374 | 0.2097 | 0.1524 | 0.074* | |
H12B | 0.3061 | 0.2302 | 0.1780 | 0.074* | |
C13 | 0.5018 (4) | 0.4223 (3) | 0.2206 (3) | 0.0598 (10) | |
C14 | 0.5169 (4) | 0.4910 (3) | 0.3133 (3) | 0.0539 (9) | |
C15 | 0.6404 (4) | 0.6210 (3) | 0.4111 (3) | 0.0705 (11) | |
H15A | 0.6423 | 0.5787 | 0.4702 | 0.085* | |
H15B | 0.5742 | 0.6743 | 0.4057 | 0.085* | |
C16 | 0.7611 (4) | 0.6753 (4) | 0.4156 (4) | 0.1046 (16) | |
H16A | 0.8246 | 0.6219 | 0.4152 | 0.157* | |
H16B | 0.7816 | 0.7173 | 0.4749 | 0.157* | |
H16C | 0.7557 | 0.7221 | 0.3597 | 0.157* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0479 (5) | 0.0345 (5) | 0.0484 (5) | −0.0014 (4) | 0.0111 (4) | −0.0009 (4) |
O1 | 0.068 (2) | 0.105 (2) | 0.083 (2) | 0.0049 (16) | −0.0142 (17) | 0.0407 (17) |
O2 | 0.099 (2) | 0.0392 (15) | 0.0726 (18) | −0.0055 (15) | 0.0123 (16) | 0.0008 (13) |
O3 | 0.0659 (16) | 0.0518 (14) | 0.0419 (13) | 0.0043 (11) | 0.0156 (11) | 0.0094 (11) |
O4 | 0.0561 (16) | 0.0374 (13) | 0.0761 (16) | −0.0097 (11) | 0.0047 (13) | −0.0102 (12) |
O5 | 0.070 (2) | 0.104 (2) | 0.112 (2) | 0.0413 (18) | −0.0251 (17) | −0.0567 (19) |
O6 | 0.082 (2) | 0.0768 (19) | 0.0632 (17) | −0.0175 (15) | 0.0156 (16) | −0.0083 (14) |
O7 | 0.0566 (16) | 0.0690 (17) | 0.0578 (15) | −0.0069 (13) | 0.0042 (12) | −0.0229 (13) |
N1 | 0.056 (2) | 0.050 (2) | 0.059 (2) | 0.0125 (16) | 0.0109 (17) | 0.0091 (16) |
N2 | 0.0451 (17) | 0.0363 (15) | 0.0455 (16) | 0.0027 (12) | 0.0050 (13) | −0.0092 (12) |
C1 | 0.050 (2) | 0.042 (2) | 0.0414 (19) | 0.0009 (17) | 0.0101 (16) | 0.0018 (15) |
C2 | 0.047 (2) | 0.070 (3) | 0.073 (3) | 0.006 (2) | 0.017 (2) | 0.003 (2) |
C3 | 0.062 (3) | 0.072 (3) | 0.084 (3) | −0.008 (2) | 0.032 (2) | 0.012 (2) |
C4 | 0.075 (3) | 0.056 (2) | 0.070 (3) | −0.006 (2) | 0.032 (2) | 0.014 (2) |
C5 | 0.056 (2) | 0.039 (2) | 0.054 (2) | 0.0025 (16) | 0.0137 (18) | 0.0072 (16) |
C6 | 0.046 (2) | 0.0351 (18) | 0.0382 (18) | −0.0046 (15) | 0.0088 (15) | −0.0032 (14) |
C7 | 0.045 (2) | 0.0376 (19) | 0.0441 (19) | −0.0018 (15) | 0.0078 (16) | −0.0091 (15) |
C8 | 0.059 (2) | 0.051 (2) | 0.062 (2) | −0.0047 (17) | 0.026 (2) | −0.0094 (18) |
C9 | 0.076 (3) | 0.061 (2) | 0.054 (2) | −0.002 (2) | 0.025 (2) | −0.0127 (19) |
C10 | 0.078 (3) | 0.051 (2) | 0.061 (2) | −0.0043 (19) | 0.016 (2) | −0.0168 (19) |
C11 | 0.095 (3) | 0.041 (2) | 0.067 (3) | −0.007 (2) | 0.022 (2) | −0.0048 (19) |
C12 | 0.088 (3) | 0.046 (2) | 0.050 (2) | 0.000 (2) | 0.014 (2) | −0.0057 (18) |
C13 | 0.054 (2) | 0.054 (2) | 0.066 (2) | 0.0071 (19) | −0.002 (2) | −0.0185 (19) |
C14 | 0.051 (2) | 0.050 (2) | 0.055 (2) | 0.0026 (19) | −0.005 (2) | −0.0090 (18) |
C15 | 0.072 (3) | 0.066 (3) | 0.069 (3) | −0.012 (2) | 0.003 (2) | −0.027 (2) |
C16 | 0.094 (4) | 0.094 (3) | 0.125 (4) | −0.035 (3) | 0.019 (3) | −0.045 (3) |
S1—O3 | 1.425 (2) | C7—C12 | 1.528 (4) |
S1—O4 | 1.426 (2) | C7—H7 | 0.9800 |
S1—N2 | 1.658 (3) | C8—C9 | 1.527 (4) |
O5—C13 | 1.212 (4) | C8—H8A | 0.9700 |
N2—C13 | 1.395 (4) | C8—H8B | 0.9700 |
N2—C7 | 1.502 (4) | C9—C10 | 1.524 (4) |
S1—C6 | 1.778 (3) | C9—H9A | 0.9700 |
O1—N1 | 1.216 (4) | C9—H9B | 0.9700 |
O2—N1 | 1.212 (3) | C10—C11 | 1.504 (5) |
O6—C14 | 1.195 (4) | C10—H10A | 0.9700 |
O7—C14 | 1.319 (4) | C10—H10B | 0.9700 |
O7—C15 | 1.458 (4) | C11—C12 | 1.528 (4) |
N1—C1 | 1.478 (4) | C11—H11A | 0.9700 |
C1—C2 | 1.377 (5) | C11—H11B | 0.9700 |
C1—C6 | 1.395 (4) | C12—H12A | 0.9700 |
C2—C3 | 1.377 (5) | C12—H12B | 0.9700 |
C2—H2 | 0.9300 | C13—C14 | 1.522 (5) |
C3—C4 | 1.378 (5) | C15—C16 | 1.473 (5) |
C3—H3 | 0.9300 | C15—H15A | 0.9700 |
C4—C5 | 1.376 (5) | C15—H15B | 0.9700 |
C4—H4 | 0.9300 | C16—H16A | 0.9600 |
C5—C6 | 1.390 (4) | C16—H16B | 0.9600 |
C5—H5 | 0.9300 | C16—H16C | 0.9600 |
C7—C8 | 1.514 (4) | ||
O3—S1—C6 | 106.24 (15) | C10—C9—C8 | 111.4 (3) |
O3—S1—O4 | 120.07 (14) | C10—C9—H9A | 109.4 |
O3—S1—N2 | 107.14 (13) | C8—C9—H9A | 109.4 |
O4—S1—N2 | 107.06 (14) | C10—C9—H9B | 109.4 |
O4—S1—C6 | 111.55 (14) | C8—C9—H9B | 109.4 |
N2—S1—C6 | 103.50 (14) | H9A—C9—H9B | 108.0 |
C7—N2—S1 | 116.2 (2) | C11—C10—C9 | 110.8 (3) |
C13—N2—C7 | 121.6 (2) | C11—C10—H10A | 109.5 |
C13—N2—S1 | 121.6 (2) | C9—C10—H10A | 109.5 |
C14—O7—C15 | 115.2 (3) | C11—C10—H10B | 109.5 |
O2—N1—O1 | 125.0 (3) | C9—C10—H10B | 109.5 |
O2—N1—C1 | 117.1 (3) | H10A—C10—H10B | 108.1 |
O1—N1—C1 | 117.8 (3) | C10—C11—C12 | 112.0 (3) |
C2—C1—C6 | 122.3 (3) | C10—C11—H11A | 109.2 |
C2—C1—N1 | 117.0 (3) | C12—C11—H11A | 109.2 |
C6—C1—N1 | 120.6 (3) | C10—C11—H11B | 109.2 |
C1—C2—C3 | 119.2 (3) | C12—C11—H11B | 109.2 |
C1—C2—H2 | 120.4 | H11A—C11—H11B | 107.9 |
C3—C2—H2 | 120.4 | C11—C12—C7 | 109.1 (3) |
C2—C3—C4 | 119.4 (4) | C11—C12—H12A | 109.9 |
C2—C3—H3 | 120.3 | C7—C12—H12A | 109.9 |
C4—C3—H3 | 120.3 | C11—C12—H12B | 109.9 |
C5—C4—C3 | 121.3 (3) | C7—C12—H12B | 109.9 |
C5—C4—H4 | 119.4 | H12A—C12—H12B | 108.3 |
C3—C4—H4 | 119.4 | O5—C13—N2 | 122.5 (3) |
C4—C5—C6 | 120.4 (3) | O5—C13—C14 | 119.3 (3) |
C4—C5—H5 | 119.8 | N2—C13—C14 | 117.9 (3) |
C6—C5—H5 | 119.8 | O6—C14—O7 | 127.5 (3) |
C5—C6—C1 | 117.3 (3) | O6—C14—C13 | 121.3 (3) |
C5—C6—S1 | 120.9 (2) | O7—C14—C13 | 111.0 (4) |
C1—C6—S1 | 121.4 (2) | O7—C15—C16 | 107.5 (3) |
N2—C7—C8 | 113.1 (2) | O7—C15—H15A | 110.2 |
N2—C7—C12 | 112.9 (2) | C16—C15—H15A | 110.2 |
C8—C7—C12 | 111.7 (3) | O7—C15—H15B | 110.2 |
N2—C7—H7 | 106.2 | C16—C15—H15B | 110.2 |
C8—C7—H7 | 106.2 | H15A—C15—H15B | 108.5 |
C12—C7—H7 | 106.2 | C15—C16—H16A | 109.5 |
C7—C8—C9 | 109.8 (3) | C15—C16—H16B | 109.5 |
C7—C8—H8A | 109.7 | H16A—C16—H16B | 109.5 |
C9—C8—H8A | 109.7 | C15—C16—H16C | 109.5 |
C7—C8—H8B | 109.7 | H16A—C16—H16C | 109.5 |
C9—C8—H8B | 109.7 | H16B—C16—H16C | 109.5 |
H8A—C8—H8B | 108.2 | ||
O3—S1—N2—C13 | 135.1 (3) | O4—S1—C6—C1 | 93.4 (3) |
O4—S1—N2—C13 | 5.1 (3) | N2—S1—C6—C1 | −151.9 (2) |
C6—S1—N2—C13 | −112.9 (3) | C13—N2—C7—C8 | −77.8 (4) |
O3—S1—N2—C7 | −35.9 (2) | S1—N2—C7—C8 | 93.3 (3) |
O4—S1—N2—C7 | −166.0 (2) | C13—N2—C7—C12 | 50.3 (4) |
C6—S1—N2—C7 | 76.1 (2) | S1—N2—C7—C12 | −138.7 (2) |
O2—N1—C1—C2 | 130.9 (3) | N2—C7—C8—C9 | −173.6 (3) |
O1—N1—C1—C2 | −47.8 (4) | C12—C7—C8—C9 | 57.7 (4) |
O2—N1—C1—C6 | −46.9 (4) | C7—C8—C9—C10 | −56.1 (4) |
O1—N1—C1—C6 | 134.4 (3) | C8—C9—C10—C11 | 55.5 (4) |
C6—C1—C2—C3 | 1.1 (5) | C9—C10—C11—C12 | −56.1 (4) |
N1—C1—C2—C3 | −176.7 (3) | C10—C11—C12—C7 | 56.6 (4) |
C1—C2—C3—C4 | 0.2 (6) | N2—C7—C12—C11 | 173.7 (3) |
C2—C3—C4—C5 | −1.0 (6) | C8—C7—C12—C11 | −57.5 (4) |
C3—C4—C5—C6 | 0.4 (5) | C7—N2—C13—O5 | 14.3 (6) |
C4—C5—C6—C1 | 0.8 (5) | S1—N2—C13—O5 | −156.2 (3) |
C4—C5—C6—S1 | −172.5 (3) | C7—N2—C13—C14 | −158.5 (3) |
C2—C1—C6—C5 | −1.6 (5) | S1—N2—C13—C14 | 30.9 (4) |
N1—C1—C6—C5 | 176.1 (3) | C15—O7—C14—O6 | −6.1 (5) |
C2—C1—C6—S1 | 171.7 (3) | C15—O7—C14—C13 | 179.1 (3) |
N1—C1—C6—S1 | −10.6 (4) | O5—C13—C14—O6 | −114.0 (5) |
O3—S1—C6—C5 | 133.9 (2) | N2—C13—C14—O6 | 59.1 (5) |
O4—S1—C6—C5 | −93.6 (3) | O5—C13—C14—O7 | 61.2 (5) |
N2—S1—C6—C5 | 21.2 (3) | N2—C13—C14—O7 | −125.7 (3) |
O3—S1—C6—C1 | −39.2 (3) | C14—O7—C15—C16 | 176.2 (3) |
Experimental details
Crystal data | |
Chemical formula | C16H20N2O7S |
Mr | 384.40 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 294 |
a, b, c (Å) | 10.962 (7), 12.352 (7), 13.879 (8) |
β (°) | 101.813 (11) |
V (Å3) | 1839.5 (19) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.22 |
Crystal size (mm) | 0.24 × 0.22 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART 1000 CCD area-detector |
Absorption correction | Multi-scan (SADABS; Bruker, 1998) |
Tmin, Tmax | 0.896, 0.960 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 9177, 3240, 1813 |
Rint | 0.074 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.047, 0.129, 1.01 |
No. of reflections | 3240 |
No. of parameters | 237 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.26 |
Computer programs: SMART (Bruker, 1998), SAINT (Bruker, 1998), SAINT, SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1998), SHELXTL and PLATON (Spek, 2003).
Inhibitors of KARI (ketol-acid reductoisomerase) have been synthesized and tested as herbicides. 2-Dimethylphosphinoyl-2-hydroxy acetic acid (Hoe 704, Schulz et al., 1988), N-hydroxy-N-isopropyloxamate (IpOHA, Aulabaugh et al., 1990) and cyclopropane-1,1-dicarboxylate (CPD, Lee et al., 2005) are potent inhibitors of the enzyme in vitro but their activity as herbicides are weak. There are few reports about the design, synthesis and biological activity of new KARI inhibitors. Nevertheless, inhibitors of KARI remain a potential source for finding novel herbicidal compounds (Wang et al., 2005). With this in mind, a series of ethyl-2-(N-substituted-arylsulfonamido)-2-oxoacetate compounds has been designed and synthesized, based on the structure of KARI inhibitor IpOHA. The X-ray crystal structure determination of the title compound, (I), was undertaken in order to investigate the relationship between structure and herbicidal activity.
The X-ray analysis reveals that in the title compound, the cyclohexane ring is in a chair conformation and is bonded to the amine N atom (Fig. 1). Two C═ O groups are trans arranged, with the torsion angle O5—C13—C14—O6 being -114.0 (5)°. The dihedral angle between the tertiary amine plane (S1/C7/C13/N2) and ethoxylcarbonyl O—C═O group (O6/O7/O14) is 75.1 (2)°. The dihedral angle between the amine plane and benzene ring C1···C6 is 74.0 (2)°.