The title compound, C
24H
22N
2O
4, is a methyl ester of a 2-pyridylalanine in which the amine group is protected. The molecule has four essentially planar segments. Apart from a relatively weak N—H
O hydrogen bond, molecules are held together in the solid state only by van der Waals interactions.
Supporting information
CCDC reference: 222847
Key indicators
- Single-crystal X-ray study
- T = 173 K
- Mean (C-C) = 0.007 Å
- R factor = 0.052
- wR factor = 0.090
- Data-to-parameter ratio = 6.8
checkCIF/PLATON results
No syntax errors found
Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low ..... 0.92
Alert level B
RINTA01_ALERT_3_B The value of Rint is greater than 0.15
Rint given 0.158
PLAT020_ALERT_3_B The value of Rint is greater than 0.10 ....... 0.16
Alert level C
GOODF01_ALERT_2_C The least squares goodness of fit parameter lies
outside the range 0.80 <> 2.00
Goodness of fit given = 0.797
REFLT03_ALERT_1_C Reflection count < 95% complete
From the CIF: _diffrn_reflns_theta_max 25.00
From the CIF: _diffrn_reflns_theta_full 0.00
From the CIF: _reflns_number_total 1863
TEST2: Reflns within _diffrn_reflns_theta_max
Count of symmetry unique reflns 2023
Completeness (_total/calc) 92.09%
REFNR01_ALERT_3_C Ratio of reflections to parameters is < 8 for a
non-centrosymmetric structure, where ZMAX < 18
sine(theta)/lambda -0.1862
Proportion of unique data used 1.0000
Ratio reflections to parameters 6.8242
PLAT022_ALERT_3_C Ratio Unique / Expected Reflections too Low .. 0.92
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) ... 6.82
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given ..... ?
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang.. 7
Alert level G
REFLT03_ALERT_1_G ALERT: Expected hkl max differ from CIF values
From the CIF: _diffrn_reflns_theta_max 25.00
From the CIF: _reflns_number_total 1863
From the CIF: _diffrn_reflns_limit_ max hkl 6. 15. 28.
From the CIF: _diffrn_reflns_limit_ min hkl -6. -11. -28.
TEST1: Expected hkl limits for theta max
Calculated maximum hkl 6. 17. 28.
Calculated minimum hkl -6. -17. -28.
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 25.00
From the CIF: _reflns_number_total 1863
Count of symmetry unique reflns 2023
Completeness (_total/calc) 92.09%
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
1 ALERT level A = In general: serious problem
2 ALERT level B = Potentially serious problem
7 ALERT level C = Check and explain
2 ALERT level G = General alerts; check
2 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
1 ALERT type 2 Indicator that the structure model may be wrong or deficient
7 ALERT type 3 Indicator that the structure quality may be low
2 ALERT type 4 Improvement, methodology, query or suggestion
The synthesis of the title compound is described by Tabanella et al. (2003).
H atoms were positioned geometrically and refined with a riding model (including free rotation about C—C bonds), and with Uiso constrained to be 1.2 (1.5 for methyl groups) times Ueq of the carrier atom. In the absence of significant anomalous scattering effects, the absolute configuration could not be confirmed from the diffraction data; it was assumed from the known configuration of the starting material, and Friedel pairs were merged.
Data collection: SMART (Bruker, 2001); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2001); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and local programs.
Methyl 2(
S)-(
N-fluoren-9-ylmethoxycarbonylamino)-3-(2-pyridyl)propionate
top
Crystal data top
C24H22N2O4 | Dx = 1.371 Mg m−3 |
Mr = 402.44 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, P212121 | Cell parameters from 2523 reflections |
a = 5.524 (4) Å | θ = 2.2–25.8° |
b = 14.988 (11) Å | µ = 0.09 mm−1 |
c = 23.557 (18) Å | T = 173 K |
V = 1950 (3) Å3 | Needle, colourless |
Z = 4 | 0.48 × 0.09 × 0.06 mm |
F(000) = 848 | |
Data collection top
Bruker SMART 1K CCD diffractometer | 1042 reflections with I > 2σ(I) |
Radiation source: sealed tube | Rint = 0.158 |
Graphite monochromator | θmax = 25.0°, θmin = 1.7° |
Detector resolution: 8.192 pixels mm-1 | h = −6→6 |
narrow–frame ω scans | k = −11→15 |
6519 measured reflections | l = −28→28 |
1863 independent reflections | |
Refinement top
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)] = 0.052 | H-atom parameters constrained |
wR(F2) = 0.090 | w = 1/[σ2(Fo2) + (0.0258P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.80 | (Δ/σ)max < 0.001 |
1863 reflections | Δρmax = 0.19 e Å−3 |
273 parameters | Δρmin = −0.23 e Å−3 |
0 restraints | Extinction correction: SHELXTL, Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0073 (12) |
Crystal data top
C24H22N2O4 | V = 1950 (3) Å3 |
Mr = 402.44 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 5.524 (4) Å | µ = 0.09 mm−1 |
b = 14.988 (11) Å | T = 173 K |
c = 23.557 (18) Å | 0.48 × 0.09 × 0.06 mm |
Data collection top
Bruker SMART 1K CCD diffractometer | 1042 reflections with I > 2σ(I) |
6519 measured reflections | Rint = 0.158 |
1863 independent reflections | |
Refinement top
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.090 | H-atom parameters constrained |
S = 0.80 | Δρmax = 0.19 e Å−3 |
1863 reflections | Δρmin = −0.23 e Å−3 |
273 parameters | |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
C1 | 0.3623 (8) | 0.5721 (4) | 0.5524 (2) | 0.0315 (14) | |
N1 | 0.4492 (8) | 0.6179 (3) | 0.50819 (16) | 0.0370 (12) | |
C2 | 0.6059 (10) | 0.6832 (4) | 0.5197 (2) | 0.0479 (16) | |
H2 | 0.6654 | 0.7176 | 0.4888 | 0.058* | |
C3 | 0.6875 (9) | 0.7044 (4) | 0.5736 (2) | 0.0466 (16) | |
H3 | 0.8014 | 0.7509 | 0.5797 | 0.056* | |
C4 | 0.5957 (10) | 0.6547 (4) | 0.6180 (2) | 0.0525 (18) | |
H4 | 0.6437 | 0.6671 | 0.6559 | 0.063* | |
C5 | 0.4364 (9) | 0.5880 (4) | 0.6069 (2) | 0.0435 (16) | |
H5 | 0.3761 | 0.5523 | 0.6371 | 0.052* | |
C6 | 0.1889 (8) | 0.4990 (4) | 0.53975 (17) | 0.0330 (14) | |
H6A | 0.0228 | 0.5237 | 0.5411 | 0.040* | |
H6B | 0.2016 | 0.4536 | 0.5701 | 0.040* | |
C7 | 0.2238 (8) | 0.4524 (3) | 0.48228 (19) | 0.0334 (14) | |
H7 | 0.1217 | 0.3973 | 0.4837 | 0.040* | |
C8 | 0.1370 (8) | 0.5049 (4) | 0.4303 (2) | 0.0310 (14) | |
O1 | 0.2444 (6) | 0.5094 (3) | 0.38623 (13) | 0.0479 (11) | |
O2 | −0.0756 (5) | 0.5433 (2) | 0.43985 (12) | 0.0369 (10) | |
C9 | −0.1820 (8) | 0.5855 (4) | 0.39104 (19) | 0.0436 (15) | |
H9A | −0.2013 | 0.5415 | 0.3606 | 0.065* | |
H9B | −0.0766 | 0.6339 | 0.3780 | 0.065* | |
H9C | −0.3408 | 0.6099 | 0.4013 | 0.065* | |
N2 | 0.4662 (6) | 0.4224 (3) | 0.47369 (14) | 0.0295 (11) | |
H2N | 0.5880 | 0.4576 | 0.4826 | 0.035* | |
C10 | 0.5101 (9) | 0.3413 (4) | 0.45225 (18) | 0.0274 (14) | |
O3 | 0.3698 (6) | 0.2803 (3) | 0.44961 (13) | 0.0363 (10) | |
O4 | 0.7398 (5) | 0.3359 (2) | 0.43328 (12) | 0.0320 (9) | |
C11 | 0.8216 (8) | 0.2504 (3) | 0.41180 (18) | 0.0325 (15) | |
H11A | 0.6871 | 0.2068 | 0.4130 | 0.039* | |
H11B | 0.9551 | 0.2275 | 0.4358 | 0.039* | |
C12 | 0.9088 (8) | 0.2619 (3) | 0.35102 (17) | 0.0274 (14) | |
H12 | 1.0297 | 0.3115 | 0.3491 | 0.033* | |
C13 | 0.7100 (9) | 0.2773 (4) | 0.30720 (19) | 0.0309 (14) | |
C14 | 0.7130 (8) | 0.2090 (4) | 0.26681 (19) | 0.0302 (14) | |
C15 | 0.5458 (9) | 0.2071 (4) | 0.22334 (19) | 0.0389 (16) | |
H15 | 0.5476 | 0.1601 | 0.1963 | 0.047* | |
C16 | 0.3776 (10) | 0.2737 (4) | 0.2197 (2) | 0.0447 (16) | |
H16 | 0.2623 | 0.2732 | 0.1898 | 0.054* | |
C17 | 0.3740 (9) | 0.3424 (4) | 0.2596 (2) | 0.0419 (16) | |
H17 | 0.2562 | 0.3882 | 0.2561 | 0.050* | |
C18 | 0.5392 (9) | 0.3457 (4) | 0.3046 (2) | 0.0365 (15) | |
H18 | 0.5352 | 0.3922 | 0.3320 | 0.044* | |
C19 | 1.0234 (8) | 0.1756 (3) | 0.32964 (18) | 0.0264 (13) | |
C20 | 0.9025 (8) | 0.1454 (4) | 0.2814 (2) | 0.0301 (13) | |
C21 | 0.9781 (9) | 0.0691 (4) | 0.25342 (19) | 0.0371 (15) | |
H21 | 0.8979 | 0.0494 | 0.2200 | 0.045* | |
C22 | 1.1738 (9) | 0.0221 (4) | 0.2752 (2) | 0.0459 (16) | |
H22 | 1.2251 | −0.0317 | 0.2576 | 0.055* | |
C23 | 1.2932 (9) | 0.0534 (4) | 0.3225 (2) | 0.0436 (16) | |
H23 | 1.4323 | 0.0225 | 0.3358 | 0.052* | |
C24 | 1.2155 (8) | 0.1289 (3) | 0.35116 (19) | 0.0323 (14) | |
H24 | 1.2939 | 0.1479 | 0.3850 | 0.039* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
C1 | 0.021 (3) | 0.035 (4) | 0.039 (3) | 0.006 (3) | −0.002 (2) | −0.007 (3) |
N1 | 0.042 (3) | 0.028 (4) | 0.041 (2) | −0.006 (2) | −0.003 (2) | 0.002 (3) |
C2 | 0.043 (3) | 0.044 (5) | 0.057 (4) | −0.008 (3) | −0.002 (3) | 0.004 (4) |
C3 | 0.029 (3) | 0.049 (5) | 0.062 (4) | −0.005 (3) | −0.007 (3) | −0.020 (4) |
C4 | 0.035 (3) | 0.086 (6) | 0.036 (3) | −0.011 (4) | 0.001 (3) | −0.018 (4) |
C5 | 0.033 (3) | 0.061 (5) | 0.036 (3) | −0.011 (3) | 0.001 (3) | −0.007 (3) |
C6 | 0.029 (3) | 0.042 (4) | 0.028 (2) | 0.004 (3) | 0.004 (2) | 0.004 (3) |
C7 | 0.024 (3) | 0.036 (4) | 0.040 (3) | 0.006 (3) | 0.008 (3) | −0.008 (3) |
C8 | 0.019 (3) | 0.037 (4) | 0.037 (3) | −0.002 (3) | −0.002 (3) | −0.009 (3) |
O1 | 0.028 (2) | 0.085 (3) | 0.0312 (18) | −0.001 (2) | 0.0046 (19) | −0.001 (2) |
O2 | 0.0220 (19) | 0.051 (3) | 0.0376 (19) | 0.0104 (18) | 0.0038 (17) | 0.002 (2) |
C9 | 0.025 (3) | 0.060 (4) | 0.046 (3) | 0.007 (3) | −0.011 (3) | 0.002 (3) |
N2 | 0.021 (2) | 0.026 (3) | 0.041 (2) | 0.003 (2) | −0.002 (2) | −0.014 (2) |
C10 | 0.024 (3) | 0.036 (5) | 0.022 (3) | 0.000 (3) | 0.003 (2) | −0.003 (3) |
O3 | 0.0234 (19) | 0.034 (3) | 0.051 (2) | −0.0078 (19) | 0.0073 (17) | −0.009 (2) |
O4 | 0.0190 (18) | 0.039 (3) | 0.0381 (17) | 0.0017 (19) | 0.0068 (16) | −0.0047 (19) |
C11 | 0.022 (3) | 0.040 (4) | 0.036 (3) | 0.004 (3) | 0.001 (2) | −0.004 (3) |
C12 | 0.019 (3) | 0.028 (4) | 0.035 (3) | −0.008 (3) | 0.008 (2) | −0.007 (3) |
C13 | 0.025 (3) | 0.036 (4) | 0.032 (3) | −0.011 (3) | 0.009 (2) | −0.001 (3) |
C14 | 0.028 (3) | 0.034 (4) | 0.028 (3) | −0.011 (3) | 0.005 (2) | 0.006 (3) |
C15 | 0.035 (3) | 0.053 (5) | 0.028 (3) | −0.013 (3) | 0.000 (3) | 0.003 (3) |
C16 | 0.033 (3) | 0.055 (5) | 0.046 (3) | −0.005 (3) | −0.009 (3) | 0.012 (4) |
C17 | 0.024 (3) | 0.051 (5) | 0.050 (3) | −0.001 (3) | 0.001 (3) | 0.024 (4) |
C18 | 0.030 (3) | 0.039 (4) | 0.040 (3) | −0.001 (3) | 0.011 (3) | 0.006 (3) |
C19 | 0.016 (3) | 0.032 (4) | 0.031 (3) | −0.005 (3) | 0.001 (2) | 0.001 (3) |
C20 | 0.024 (3) | 0.032 (4) | 0.034 (3) | −0.006 (3) | 0.001 (2) | −0.003 (3) |
C21 | 0.033 (3) | 0.048 (5) | 0.030 (3) | −0.007 (3) | 0.000 (3) | −0.006 (3) |
C22 | 0.041 (4) | 0.057 (5) | 0.039 (3) | 0.003 (3) | 0.007 (3) | −0.008 (3) |
C23 | 0.024 (3) | 0.056 (5) | 0.050 (3) | 0.009 (3) | 0.003 (3) | −0.003 (3) |
C24 | 0.023 (3) | 0.042 (4) | 0.031 (3) | −0.005 (3) | −0.002 (2) | 0.004 (3) |
Geometric parameters (Å, º) top
C1—N1 | 1.338 (6) | C11—H11A | 0.990 |
C1—C5 | 1.368 (6) | C11—H11B | 0.990 |
C1—C6 | 1.485 (7) | C11—C12 | 1.521 (6) |
N1—C2 | 1.334 (6) | C12—H12 | 1.000 |
C2—H2 | 0.950 | C12—C13 | 1.525 (6) |
C2—C3 | 1.383 (6) | C12—C19 | 1.525 (6) |
C3—H3 | 0.950 | C13—C14 | 1.398 (6) |
C3—C4 | 1.381 (7) | C13—C18 | 1.394 (6) |
C4—H4 | 0.950 | C14—C15 | 1.379 (6) |
C4—C5 | 1.357 (7) | C14—C20 | 1.457 (6) |
C5—H5 | 0.950 | C15—H15 | 0.950 |
C6—H6A | 0.990 | C15—C16 | 1.366 (7) |
C6—H6B | 0.990 | C16—H16 | 0.950 |
C6—C7 | 1.536 (6) | C16—C17 | 1.394 (7) |
C7—H7 | 1.000 | C17—H17 | 0.950 |
C7—C8 | 1.533 (6) | C17—C18 | 1.400 (6) |
C7—N2 | 1.427 (6) | C18—H18 | 0.950 |
C8—O1 | 1.197 (5) | C19—C20 | 1.394 (6) |
C8—O2 | 1.327 (5) | C19—C24 | 1.368 (6) |
O2—C9 | 1.438 (5) | C20—C21 | 1.384 (6) |
C9—H9A | 0.980 | C21—H21 | 0.950 |
C9—H9B | 0.980 | C21—C22 | 1.390 (7) |
C9—H9C | 0.980 | C22—H22 | 0.950 |
N2—H2N | 0.880 | C22—C23 | 1.377 (6) |
N2—C10 | 1.338 (6) | C23—H23 | 0.950 |
C10—O3 | 1.201 (5) | C23—C24 | 1.386 (6) |
C10—O4 | 1.347 (5) | C24—H24 | 0.950 |
O4—C11 | 1.450 (5) | | |
| | | |
N1—C1—C5 | 122.3 (5) | O4—C11—C12 | 109.1 (4) |
N1—C1—C6 | 117.0 (4) | H11A—C11—H11B | 108.3 |
C5—C1—C6 | 120.7 (5) | H11A—C11—C12 | 109.9 |
C1—N1—C2 | 116.8 (5) | H11B—C11—C12 | 109.9 |
N1—C2—H2 | 117.7 | C11—C12—H12 | 109.8 |
N1—C2—C3 | 124.5 (6) | C11—C12—C13 | 115.2 (4) |
H2—C2—C3 | 117.7 | C11—C12—C19 | 110.3 (4) |
C2—C3—H3 | 121.6 | H12—C12—C13 | 109.8 |
C2—C3—C4 | 116.9 (5) | H12—C12—C19 | 109.8 |
H3—C3—C4 | 121.6 | C13—C12—C19 | 101.8 (4) |
C3—C4—H4 | 120.4 | C12—C13—C14 | 110.0 (4) |
C3—C4—C5 | 119.3 (5) | C12—C13—C18 | 128.9 (5) |
H4—C4—C5 | 120.4 | C14—C13—C18 | 121.1 (5) |
C1—C5—C4 | 120.2 (5) | C13—C14—C15 | 120.8 (5) |
C1—C5—H5 | 119.9 | C13—C14—C20 | 109.1 (4) |
C4—C5—H5 | 119.9 | C15—C14—C20 | 130.0 (5) |
C1—C6—H6A | 108.4 | C14—C15—H15 | 120.4 |
C1—C6—H6B | 108.4 | C14—C15—C16 | 119.1 (5) |
C1—C6—C7 | 115.6 (4) | H15—C15—C16 | 120.4 |
H6A—C6—H6B | 107.4 | C15—C16—H16 | 119.8 |
H6A—C6—C7 | 108.4 | C15—C16—C17 | 120.5 (5) |
H6B—C6—C7 | 108.4 | H16—C16—C17 | 119.8 |
C6—C7—H7 | 105.9 | C16—C17—H17 | 119.1 |
C6—C7—C8 | 115.5 (4) | C16—C17—C18 | 121.8 (5) |
C6—C7—N2 | 112.7 (4) | H17—C17—C18 | 119.1 |
H7—C7—C8 | 105.9 | C13—C18—C17 | 116.6 (5) |
H7—C7—N2 | 105.9 | C13—C18—H18 | 121.7 |
C8—C7—N2 | 110.0 (4) | C17—C18—H18 | 121.7 |
C7—C8—O1 | 124.5 (4) | C12—C19—C20 | 110.2 (4) |
C7—C8—O2 | 111.4 (4) | C12—C19—C24 | 129.3 (4) |
O1—C8—O2 | 124.1 (5) | C20—C19—C24 | 120.5 (5) |
C8—O2—C9 | 114.7 (4) | C14—C20—C19 | 108.9 (5) |
O2—C9—H9A | 109.5 | C14—C20—C21 | 130.2 (5) |
O2—C9—H9B | 109.5 | C19—C20—C21 | 120.8 (5) |
O2—C9—H9C | 109.5 | C20—C21—H21 | 120.7 |
H9A—C9—H9B | 109.5 | C20—C21—C22 | 118.6 (5) |
H9A—C9—H9C | 109.5 | H21—C21—C22 | 120.7 |
H9B—C9—H9C | 109.5 | C21—C22—H22 | 120.1 |
C7—N2—H2N | 119.7 | C21—C22—C23 | 119.9 (5) |
C7—N2—C10 | 120.6 (4) | H22—C22—C23 | 120.1 |
H2N—N2—C10 | 119.7 | C22—C23—H23 | 119.2 |
N2—C10—O3 | 126.5 (5) | C22—C23—C24 | 121.6 (5) |
N2—C10—O4 | 110.5 (5) | H23—C23—C24 | 119.2 |
O3—C10—O4 | 123.0 (5) | C19—C24—C23 | 118.5 (4) |
C10—O4—C11 | 117.5 (4) | C19—C24—H24 | 120.7 |
O4—C11—H11A | 109.9 | C23—C24—H24 | 120.7 |
O4—C11—H11B | 109.9 | | |
| | | |
C5—C1—N1—C2 | −2.7 (7) | C12—C13—C14—C15 | 178.5 (4) |
C6—C1—N1—C2 | −179.7 (4) | C12—C13—C14—C20 | 1.2 (5) |
C1—N1—C2—C3 | 1.8 (8) | C18—C13—C14—C15 | −0.3 (7) |
N1—C2—C3—C4 | −1.1 (8) | C18—C13—C14—C20 | −177.6 (4) |
C2—C3—C4—C5 | 1.0 (8) | C13—C14—C15—C16 | 0.7 (7) |
C3—C4—C5—C1 | −1.9 (9) | C20—C14—C15—C16 | 177.4 (5) |
N1—C1—C5—C4 | 2.8 (8) | C14—C15—C16—C17 | −0.3 (8) |
C6—C1—C5—C4 | 179.7 (5) | C15—C16—C17—C18 | −0.4 (8) |
N1—C1—C6—C7 | 30.3 (6) | C12—C13—C18—C17 | −179.0 (4) |
C5—C1—C6—C7 | −146.7 (5) | C14—C13—C18—C17 | −0.4 (7) |
C1—C6—C7—C8 | −75.6 (5) | C16—C17—C18—C13 | 0.8 (7) |
C1—C6—C7—N2 | 52.0 (6) | C11—C12—C19—C20 | 121.5 (4) |
C6—C7—C8—O1 | 138.5 (5) | C11—C12—C19—C24 | −58.4 (6) |
C6—C7—C8—O2 | −42.9 (6) | C13—C12—C19—C20 | −1.3 (5) |
N2—C7—C8—O1 | 9.5 (7) | C13—C12—C19—C24 | 178.8 (5) |
N2—C7—C8—O2 | −171.9 (4) | C12—C19—C20—C14 | 2.1 (5) |
C7—C8—O2—C9 | −173.3 (4) | C12—C19—C20—C21 | 178.3 (4) |
O1—C8—O2—C9 | 5.3 (7) | C24—C19—C20—C14 | −178.0 (4) |
C6—C7—N2—C10 | 136.1 (4) | C24—C19—C20—C21 | −1.8 (7) |
C8—C7—N2—C10 | −93.4 (5) | C13—C14—C20—C19 | −2.1 (5) |
C7—N2—C10—O3 | −17.0 (7) | C13—C14—C20—C21 | −177.8 (5) |
C7—N2—C10—O4 | 163.1 (4) | C15—C14—C20—C19 | −179.1 (5) |
N2—C10—O4—C11 | 176.3 (3) | C15—C14—C20—C21 | 5.2 (9) |
O3—C10—O4—C11 | −3.6 (6) | C14—C20—C21—C22 | 176.8 (5) |
C10—O4—C11—C12 | 122.7 (4) | C19—C20—C21—C22 | 1.5 (7) |
O4—C11—C12—C13 | −72.2 (5) | C20—C21—C22—C23 | −2.3 (7) |
O4—C11—C12—C19 | 173.4 (3) | C21—C22—C23—C24 | 3.5 (7) |
C11—C12—C13—C14 | −119.3 (4) | C12—C19—C24—C23 | −177.3 (4) |
C11—C12—C13—C18 | 59.4 (7) | C20—C19—C24—C23 | 2.8 (7) |
C19—C12—C13—C14 | 0.0 (5) | C22—C23—C24—C19 | −3.7 (7) |
C19—C12—C13—C18 | 178.7 (5) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
N2—H2N···O2i | 0.88 | 2.47 | 3.214 (5) | 142 |
Symmetry code: (i) x+1, y, z. |
Experimental details
Crystal data |
Chemical formula | C24H22N2O4 |
Mr | 402.44 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 173 |
a, b, c (Å) | 5.524 (4), 14.988 (11), 23.557 (18) |
V (Å3) | 1950 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.48 × 0.09 × 0.06 |
|
Data collection |
Diffractometer | Bruker SMART 1K CCD diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 6519, 1863, 1042 |
Rint | 0.158 |
(sin θ/λ)max (Å−1) | 0.595 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.090, 0.80 |
No. of reflections | 1863 |
No. of parameters | 273 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.19, −0.23 |
Selected torsion angles (º) topN1—C1—C6—C7 | 30.3 (6) | C6—C7—N2—C10 | 136.1 (4) |
C5—C1—C6—C7 | −146.7 (5) | C8—C7—N2—C10 | −93.4 (5) |
C1—C6—C7—C8 | −75.6 (5) | C7—N2—C10—O4 | 163.1 (4) |
C1—C6—C7—N2 | 52.0 (6) | N2—C10—O4—C11 | 176.3 (3) |
C6—C7—C8—O2 | −42.9 (6) | C10—O4—C11—C12 | 122.7 (4) |
N2—C7—C8—O2 | −171.9 (4) | O4—C11—C12—C13 | −72.2 (5) |
C7—C8—O2—C9 | −173.3 (4) | O4—C11—C12—C19 | 173.4 (3) |
The title compound, (I), was prepared in a study of the preparation of enantiomerically pure pyridylamino acids (Tabanella et al., 2003). It was obtained from a palladium-catalysed coupling reaction of 2-bromopyridine with a fluorenylmethyoxycarbonyl-protected (Fmoc-protected) zinc reagent derived from iodoalanine methyl ester. Its structure was determined in order to confirm the identity of the product and to establish the nature of any inter- or intramolecular hydrogen bonding.
The molecule consists of four planar segments (Fig. 1), viz. the fluorene group, the ester and amine linkage from C7 to C11, the methyl ester attached to C7, and the pyridylmethyl group. The main torsion angles defining the conformational arrangement of these segments are given in Table 1. Bond lengths and angles are unexceptional.
Only one, relatively weak, intermolecular hydrogen bond is found, linking the single donor, the N—H group, with atom O2 of an adjacent molecule, with an N···O distance of 3.214 (5) Å and an angle of 142° at the H atom. Neither of the carbonyl O atoms acts as a hydrogen-bond acceptor.
Although complexes with deprotonated β-(2-pyridyl)-α-alanine as a ligand have been crystallographically characterized (Ebner et al., 1979, 1980; Ebner & Angelici, 1981), no crystal structures have been reported for the amino acid itself or for protected derivatives.