The preparation, characterization, and molecular and crystal structures of the title compound [IUPAC name: 2-nitrophenyl 2-methyl-2-(para-toluenesulfonylamino)propanoate], C17H18N2O6S, are reported. The phenyl group is almost perpendicular to the plane of the adjacent ester moiety. One O atom of the nitro group is wedged between the two ester O atoms. The implications of this peculiar conformation for the chemistry of ortho-nitrophenyl esters in peptide synthesis are discussed.
Supporting information
CCDC reference: 184490
Data collection: FEBO (Belletti, 1993); cell refinement: FEBO; data reduction: FEBO; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: PARST96 (Nardelli, 1995).
2-nitrophenyl 2-methyl-2-(
para-toluenesulfonylamino)propanoate
top
Crystal data top
C17H18N2O6S | F(000) = 1584 |
Mr = 378.39 | Dx = 1.358 Mg m−3 |
Monoclinic, C2/c | Melting point = 413–414 K |
Hall symbol: -C 2yc | Mo Kα radiation, λ = 0.71073 Å |
a = 36.449 (3) Å | Cell parameters from 48 reflections |
b = 9.082 (2) Å | θ = 7–12° |
c = 11.636 (2) Å | µ = 0.21 mm−1 |
β = 106.10 (7)° | T = 293 K |
V = 3700.8 (17) Å3 | Prism, colourless |
Z = 8 | 0.5 × 0.3 × 0.3 mm |
Data collection top
Philips PW1100 diffractometer | Rint = 0.021 |
Radiation source: fine-focus sealed tube | θmax = 26.4°, θmin = 2.8° |
Graphite monochromator | h = −45→43 |
θ/2θ scans | k = 0→11 |
3981 measured reflections | l = 0→14 |
3785 independent reflections | 3 standard reflections every 50 reflections |
2144 reflections with I > 2σ(I) | intensity decay: none |
Refinement top
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.047 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.144 | H-atom parameters constrained |
S = 0.92 | w = 1/[σ2(Fo2) + (0.0825P)2] where P = (Fo2 + 2Fc2)/3 |
3785 reflections | (Δ/σ)max = 0.001 |
237 parameters | Δρmax = 0.32 e Å−3 |
0 restraints | Δρmin = −0.33 e Å−3 |
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 | x | y | z | Uiso*/Ueq | Occ. (<1) |
S1 | 0.159604 (19) | 0.06512 (7) | 0.85370 (5) | 0.0460 (2) | |
O4 | 0.08239 (5) | 0.25421 (18) | 0.65733 (13) | 0.0464 (4) | |
O1 | 0.16466 (5) | 0.1328 (2) | 0.74772 (16) | 0.0602 (5) | |
O2 | 0.17315 (6) | 0.1374 (2) | 0.96724 (16) | 0.0620 (6) | |
O3 | 0.09049 (6) | 0.0876 (2) | 0.52594 (15) | 0.0667 (6) | |
O5 | 0.01270 (7) | 0.2280 (4) | 0.5083 (3) | 0.1359 (14) | |
O6 | −0.00882 (9) | 0.3861 (4) | 0.3773 (3) | 0.1406 (14) | |
N1 | 0.11416 (6) | 0.0471 (2) | 0.83265 (16) | 0.0443 (5) | |
H1 | 0.1053 | 0.0653 | 0.8923 | 0.053* | |
N2 | 0.01754 (8) | 0.3320 (3) | 0.4525 (2) | 0.0755 (8) | |
C1 | 0.22880 (11) | −0.5468 (4) | 0.8990 (4) | 0.1073 (15) | |
H1A | 0.2279 | −0.5880 | 0.9742 | 0.161* | 0.50 |
H1B | 0.2548 | −0.5437 | 0.8955 | 0.161* | 0.50 |
H1C | 0.2140 | −0.6067 | 0.8349 | 0.161* | 0.50 |
H1D | 0.2365 | −0.5709 | 0.8289 | 0.161* | 0.50 |
H1E | 0.2096 | −0.6152 | 0.9075 | 0.161* | 0.50 |
H1F | 0.2505 | −0.5522 | 0.9682 | 0.161* | 0.50 |
C2 | 0.21266 (8) | −0.3926 (3) | 0.8873 (3) | 0.0692 (9) | |
C3 | 0.21036 (9) | −0.3058 (4) | 0.7880 (3) | 0.0734 (9) | |
H3 | 0.2195 | −0.3428 | 0.7268 | 0.088* | |
C4 | 0.19487 (8) | −0.1660 (4) | 0.7766 (3) | 0.0627 (8) | |
H4 | 0.1936 | −0.1101 | 0.7086 | 0.075* | |
C5 | 0.18121 (7) | −0.1099 (3) | 0.8676 (2) | 0.0453 (6) | |
C6 | 0.18382 (8) | −0.1932 (3) | 0.9692 (2) | 0.0575 (7) | |
H6 | 0.1751 | −0.1557 | 1.0312 | 0.069* | |
C7 | 0.19947 (9) | −0.3322 (3) | 0.9776 (3) | 0.0689 (9) | |
H7 | 0.2012 | −0.3873 | 1.0463 | 0.083* | |
C8 | 0.08643 (7) | 0.0016 (3) | 0.7187 (2) | 0.0443 (6) | |
C9 | 0.04642 (8) | 0.0087 (4) | 0.7398 (3) | 0.0630 (8) | |
H9A | 0.0445 | −0.0655 | 0.7966 | 0.094* | |
H9B | 0.0273 | −0.0082 | 0.6656 | 0.094* | |
H9C | 0.0427 | 0.1040 | 0.7703 | 0.094* | |
C10 | 0.09383 (9) | −0.1514 (3) | 0.6765 (3) | 0.0663 (8) | |
H10A | 0.1172 | −0.1507 | 0.6538 | 0.099* | |
H10B | 0.0731 | −0.1791 | 0.6091 | 0.099* | |
H10C | 0.0958 | −0.2208 | 0.7402 | 0.099* | |
C11 | 0.08728 (7) | 0.1153 (3) | 0.6234 (2) | 0.0421 (6) | |
C12 | 0.08504 (8) | 0.3656 (3) | 0.5769 (2) | 0.0450 (6) | |
C13 | 0.11873 (8) | 0.4419 (3) | 0.6004 (2) | 0.0560 (7) | |
H13 | 0.1387 | 0.4177 | 0.6669 | 0.067* | |
C14 | 0.12326 (9) | 0.5552 (3) | 0.5254 (3) | 0.0658 (8) | |
H14 | 0.1462 | 0.6068 | 0.5417 | 0.079* | |
C15 | 0.09371 (11) | 0.5906 (4) | 0.4271 (3) | 0.0717 (9) | |
H15 | 0.0969 | 0.6651 | 0.3758 | 0.086* | |
C16 | 0.05983 (11) | 0.5173 (4) | 0.4043 (3) | 0.0733 (9) | |
H16 | 0.0399 | 0.5429 | 0.3380 | 0.088* | |
C17 | 0.05484 (8) | 0.4043 (3) | 0.4793 (2) | 0.0551 (7) | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
S1 | 0.0514 (4) | 0.0496 (4) | 0.0368 (3) | −0.0020 (3) | 0.0119 (3) | 0.0042 (3) |
O4 | 0.0665 (12) | 0.0432 (10) | 0.0323 (9) | 0.0020 (9) | 0.0186 (8) | −0.0006 (7) |
O1 | 0.0591 (12) | 0.0714 (13) | 0.0538 (11) | −0.0032 (10) | 0.0220 (9) | 0.0221 (10) |
O2 | 0.0692 (13) | 0.0618 (13) | 0.0457 (10) | 0.0005 (10) | 0.0004 (9) | −0.0092 (9) |
O3 | 0.1056 (17) | 0.0647 (13) | 0.0366 (10) | 0.0067 (12) | 0.0311 (10) | −0.0055 (9) |
O5 | 0.0758 (18) | 0.124 (2) | 0.177 (3) | −0.0286 (17) | −0.0166 (19) | 0.078 (2) |
O6 | 0.091 (2) | 0.190 (3) | 0.104 (2) | −0.027 (2) | −0.0328 (17) | 0.053 (2) |
N1 | 0.0517 (12) | 0.0549 (13) | 0.0291 (10) | 0.0022 (10) | 0.0158 (9) | 0.0020 (9) |
N2 | 0.0690 (18) | 0.080 (2) | 0.0648 (17) | −0.0004 (16) | −0.0031 (14) | 0.0096 (15) |
C1 | 0.077 (3) | 0.063 (2) | 0.170 (4) | 0.0108 (19) | 0.016 (3) | −0.018 (3) |
C2 | 0.0454 (17) | 0.0568 (19) | 0.100 (3) | 0.0000 (14) | 0.0115 (17) | −0.0140 (19) |
C3 | 0.064 (2) | 0.085 (2) | 0.072 (2) | 0.0101 (18) | 0.0216 (17) | −0.023 (2) |
C4 | 0.0596 (18) | 0.083 (2) | 0.0482 (16) | 0.0054 (16) | 0.0202 (14) | −0.0010 (15) |
C5 | 0.0431 (14) | 0.0548 (16) | 0.0378 (13) | −0.0001 (12) | 0.0108 (11) | −0.0004 (12) |
C6 | 0.0673 (19) | 0.0578 (17) | 0.0509 (16) | 0.0040 (15) | 0.0224 (14) | 0.0090 (14) |
C7 | 0.068 (2) | 0.0587 (19) | 0.080 (2) | 0.0045 (16) | 0.0200 (17) | 0.0188 (17) |
C8 | 0.0468 (14) | 0.0466 (14) | 0.0392 (13) | −0.0035 (12) | 0.0116 (11) | −0.0014 (11) |
C9 | 0.0533 (17) | 0.078 (2) | 0.0606 (18) | −0.0101 (16) | 0.0213 (14) | 0.0106 (16) |
C10 | 0.078 (2) | 0.0474 (17) | 0.0668 (19) | −0.0073 (15) | 0.0087 (16) | −0.0062 (15) |
C11 | 0.0453 (14) | 0.0492 (15) | 0.0324 (12) | 0.0006 (12) | 0.0116 (10) | −0.0059 (11) |
C12 | 0.0598 (16) | 0.0421 (14) | 0.0347 (13) | 0.0012 (13) | 0.0158 (11) | 0.0017 (11) |
C13 | 0.0608 (18) | 0.0544 (17) | 0.0511 (16) | 0.0005 (14) | 0.0126 (13) | 0.0082 (14) |
C14 | 0.079 (2) | 0.0556 (18) | 0.0657 (19) | −0.0081 (16) | 0.0242 (17) | 0.0080 (15) |
C15 | 0.107 (3) | 0.0558 (19) | 0.0533 (18) | −0.0030 (19) | 0.0237 (18) | 0.0139 (15) |
C16 | 0.096 (3) | 0.067 (2) | 0.0459 (17) | 0.0031 (19) | 0.0010 (16) | 0.0139 (15) |
C17 | 0.0639 (18) | 0.0544 (17) | 0.0427 (14) | 0.0021 (14) | 0.0077 (13) | 0.0018 (13) |
Geometric parameters (Å, º) top
S1—O2 | 1.4348 (19) | C4—H4 | 0.9300 |
S1—O1 | 1.4347 (18) | C5—C6 | 1.385 (3) |
S1—N1 | 1.614 (2) | C6—C7 | 1.377 (4) |
S1—C5 | 1.761 (3) | C6—H6 | 0.9300 |
O4—C11 | 1.348 (3) | C7—H7 | 0.9300 |
O4—C12 | 1.399 (3) | C8—C11 | 1.521 (3) |
O3—C11 | 1.199 (3) | C8—C10 | 1.522 (4) |
O5—N2 | 1.186 (3) | C8—C9 | 1.546 (3) |
O6—N2 | 1.210 (4) | C9—H9A | 0.9600 |
N1—C8 | 1.485 (3) | C9—H9B | 0.9600 |
N1—H1 | 0.8600 | C9—H9C | 0.9600 |
N2—C17 | 1.463 (4) | C10—H10A | 0.9600 |
C1—C2 | 1.511 (4) | C10—H10B | 0.9600 |
C1—H1A | 0.9600 | C10—H10C | 0.9600 |
C1—H1B | 0.9600 | C12—C13 | 1.370 (4) |
C1—H1C | 0.9600 | C12—C17 | 1.390 (4) |
C1—H1D | 0.9600 | C13—C14 | 1.388 (4) |
C1—H1E | 0.9600 | C13—H13 | 0.9300 |
C1—H1F | 0.9600 | C14—C15 | 1.375 (4) |
C2—C3 | 1.382 (5) | C14—H14 | 0.9300 |
C2—C7 | 1.385 (4) | C15—C16 | 1.362 (5) |
C3—C4 | 1.382 (5) | C15—H15 | 0.9300 |
C3—H3 | 0.9300 | C16—C17 | 1.392 (4) |
C4—C5 | 1.386 (4) | C16—H16 | 0.9300 |
| | | |
O2—S1—O1 | 120.14 (13) | C7—C6—C5 | 119.4 (3) |
O2—S1—N1 | 105.23 (13) | C7—C6—H6 | 120.3 |
O1—S1—N1 | 106.51 (12) | C5—C6—H6 | 120.3 |
O2—S1—C5 | 107.31 (12) | C6—C7—C2 | 122.2 (3) |
O1—S1—C5 | 107.74 (12) | C6—C7—H7 | 118.9 |
N1—S1—C5 | 109.65 (12) | C2—C7—H7 | 118.9 |
C11—O4—C12 | 116.22 (18) | N1—C8—C11 | 108.4 (2) |
C8—N1—S1 | 125.39 (16) | N1—C8—C10 | 113.8 (2) |
C8—N1—H1 | 117.3 | C11—C8—C10 | 110.1 (2) |
S1—N1—H1 | 117.3 | N1—C8—C9 | 106.6 (2) |
O5—N2—O6 | 120.7 (3) | C11—C8—C9 | 107.4 (2) |
O5—N2—C17 | 120.7 (3) | C10—C8—C9 | 110.4 (2) |
O6—N2—C17 | 118.4 (3) | C8—C9—H9A | 109.5 |
C2—C1—H1A | 109.5 | C8—C9—H9B | 109.5 |
C2—C1—H1B | 109.5 | H9A—C9—H9B | 109.5 |
H1A—C1—H1B | 109.5 | C8—C9—H9C | 109.5 |
C2—C1—H1C | 109.5 | H9A—C9—H9C | 109.5 |
H1A—C1—H1C | 109.5 | H9B—C9—H9C | 109.5 |
H1B—C1—H1C | 109.5 | C8—C10—H10A | 109.5 |
C2—C1—H1D | 109.5 | C8—C10—H10B | 109.5 |
H1A—C1—H1D | 141.1 | H10A—C10—H10B | 109.5 |
H1B—C1—H1D | 56.3 | C8—C10—H10C | 109.5 |
H1C—C1—H1D | 56.3 | H10A—C10—H10C | 109.5 |
C2—C1—H1E | 109.5 | H10B—C10—H10C | 109.5 |
H1A—C1—H1E | 56.3 | O3—C11—O4 | 121.9 (2) |
H1B—C1—H1E | 141.1 | O3—C11—C8 | 125.0 (2) |
H1C—C1—H1E | 56.3 | O4—C11—C8 | 113.00 (19) |
H1D—C1—H1E | 109.5 | C13—C12—C17 | 119.9 (2) |
C2—C1—H1F | 109.5 | C13—C12—O4 | 117.2 (2) |
H1A—C1—H1F | 56.3 | C17—C12—O4 | 122.9 (2) |
H1B—C1—H1F | 56.3 | C12—C13—C14 | 120.4 (3) |
H1C—C1—H1F | 141.1 | C12—C13—H13 | 119.8 |
H1D—C1—H1F | 109.5 | C14—C13—H13 | 119.8 |
H1E—C1—H1F | 109.5 | C15—C14—C13 | 119.6 (3) |
C3—C2—C7 | 117.1 (3) | C15—C14—H14 | 120.2 |
C3—C2—C1 | 122.4 (4) | C13—C14—H14 | 120.2 |
C7—C2—C1 | 120.5 (4) | C16—C15—C14 | 120.4 (3) |
C2—C3—C4 | 122.2 (3) | C16—C15—H15 | 119.8 |
C2—C3—H3 | 118.9 | C14—C15—H15 | 119.8 |
C4—C3—H3 | 118.9 | C15—C16—C17 | 120.5 (3) |
C3—C4—C5 | 119.2 (3) | C15—C16—H16 | 119.8 |
C3—C4—H4 | 120.4 | C17—C16—H16 | 119.8 |
C5—C4—H4 | 120.4 | C12—C17—C16 | 119.2 (3) |
C6—C5—C4 | 119.8 (3) | C12—C17—N2 | 122.6 (3) |
C6—C5—S1 | 119.7 (2) | C16—C17—N2 | 118.2 (3) |
C4—C5—S1 | 120.5 (2) | | |
| | | |
O2—S1—N1—C8 | 168.99 (19) | N1—C8—C11—O3 | 130.1 (3) |
O1—S1—N1—C8 | 40.4 (2) | C10—C8—C11—O3 | 5.1 (4) |
C5—S1—N1—C8 | −75.9 (2) | C9—C8—C11—O3 | −115.1 (3) |
C7—C2—C3—C4 | −1.4 (5) | N1—C8—C11—O4 | −52.5 (3) |
C1—C2—C3—C4 | 178.7 (3) | C10—C8—C11—O4 | −177.5 (2) |
C2—C3—C4—C5 | 0.2 (5) | C9—C8—C11—O4 | 62.3 (3) |
C3—C4—C5—C6 | 1.1 (4) | C11—O4—C12—C13 | −100.6 (3) |
C3—C4—C5—S1 | −177.5 (2) | C11—O4—C12—C17 | 82.1 (3) |
O2—S1—C5—C6 | 42.9 (2) | C17—C12—C13—C14 | −1.7 (4) |
O1—S1—C5—C6 | 173.6 (2) | O4—C12—C13—C14 | −179.2 (2) |
N1—S1—C5—C6 | −70.9 (2) | C12—C13—C14—C15 | −0.1 (4) |
O2—S1—C5—C4 | −138.5 (2) | C13—C14—C15—C16 | 1.3 (5) |
O1—S1—C5—C4 | −7.8 (3) | C14—C15—C16—C17 | −0.8 (5) |
N1—S1—C5—C4 | 107.7 (2) | C13—C12—C17—C16 | 2.2 (4) |
C4—C5—C6—C7 | −1.0 (4) | O4—C12—C17—C16 | 179.5 (3) |
S1—C5—C6—C7 | 177.6 (2) | C13—C12—C17—N2 | −177.0 (3) |
C5—C6—C7—C2 | −0.3 (5) | O4—C12—C17—N2 | 0.3 (4) |
C3—C2—C7—C6 | 1.5 (5) | C15—C16—C17—C12 | −1.0 (5) |
C1—C2—C7—C6 | −178.6 (3) | C15—C16—C17—N2 | 178.3 (3) |
S1—N1—C8—C11 | −61.5 (3) | O5—N2—C17—C12 | −6.5 (5) |
S1—N1—C8—C10 | 61.3 (3) | O6—N2—C17—C12 | 169.0 (3) |
S1—N1—C8—C9 | −176.83 (18) | O5—N2—C17—C16 | 174.3 (4) |
C12—O4—C11—O3 | −6.1 (3) | O6—N2—C17—C16 | −10.2 (5) |
C12—O4—C11—C8 | 176.4 (2) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O3i | 0.86 | 2.26 | 2.894 (3) | 131 |
Symmetry code: (i) x, −y, z+1/2. |