organic compounds
(S)-(Z)-Methyl 2-[2,3-bis(benzyloxycarbonyl)guanidino]-4-methylpentanoate
aDepartment of Chemistry, Louisiana State University, Baton Rouge, LA 70803-1804, USA, and bDepartment of Chemistry, University of South Florida, 4202 E. Fowler Avenue, CHE 205A, Tampa, FL 33620-5250, USA
*Correspondence e-mail: ffroncz@lsu.edu
The title molecule, C24H29N3O6, has a nearly planar ten-atom C3N3O4 core, on account of both N—H groups forming six-membered-ring intramolecular hydrogen bonds to carbamate carbonyl O atoms. The was determined from of light atoms in Mo Kα radiation, agreeing with the configuration of starting materials.
Related literature
For related structures, see: Travlos & White (1994); Feichtinger et al. (1998); Marsh (2002). For graph sets, see: Etter (1990). For based on from light atoms, see: Hooft et al. (2008); Fronczek (2010); Lutz & van Krieken (2010); Thompson et al. (2008).
Experimental
Crystal data
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Data collection
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Data collection: COLLECT (Nonius, 2000); cell SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO (Otwinowski & Minor, 1997) and SCALEPACK; program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97.
Supporting information
https://doi.org/10.1107/S1600536810050130/om2385sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810050130/om2385Isup2.hkl
A mixture of 1,3-bis(benzyloxycarbonyl)-2-methyl-2-thiopseudourea (2.79 mmol, 1 g), L-leucine methyl ester hydrochloride (2.79 mmol, 0.51 g), and triethylamine (2.79 mmole, 0.4 ml) in THF (absolute, 10 mL) was stirred at 338 K. The mixture was brought to room temperature, and the precipitate was filtered by vacuum. After evaporation of all solvents from the filtrate, the product was purified by δ 0.85–0.88 (dd, 6H), 1.58–1.60 (m, 2H), 1.67–1.74 (m, 1H), 3.63 (s, 3H), 4.54–4.59 (m, 1H), 7.28–7.43 (m, 10H), 8.53–8.55 (d, 1H), 11.47 (s, 1H). 13C NMR (Methanol, 400 MHz): δ 22.12, 24.95, 67.08, 68.47, 128.44, 128.54, 128.93, 129.01, 129.13, 155.36, 163.12, 172.39. MS m/z 456.21 [M+H]+, 478.19 [M+Na]+.
(EtOAc/hexane, 1:4). The product was isolated as colorless crystals in 46% yield. 1H NMR (Methanol, 400 MHz):All H atoms were visible in difference maps, and those on C were placed in idealized positions with C—H distances 0.95 - 1.00 Å and thereafter treated as riding. Coordinates for the H atoms on N were refined. Uiso for H was assigned as 1.2 times Ueq of the attached atoms (1.5 for methyl). A torsional parameter was refined for each methyl group. Friedel pairs were kept separate in the refinement.
Molecules used as drugs frequently contain heterocyclic subunits, and substituted guanidine or amidine compounds are very important intermediates in the synthesis of many
However, substituted guanidines and amidine compounds themselves can be difficult to synthesize. Thus, synthesis of substituted guanidines is important and interesting. One possible route to these compounds is to use 1,3-bis(benzyloxycarbonyl)-2-methyl-2-thiopseudourea, which has a good and L-leucine methyl ester hydrochloride, which is a good Reaction of these starting materials led to successful synthesis of the chiral title compound, which was confirmed by determination.The structure, shown in Figure 1, has a guanidine at its core. The three C—N distances of the guanidine vary from 1.3225 (12) to 1.3864 (12) Å, with the shortest being the formal double bond to the unprotonated N atom N2 and the longest being to the other carbamate N atom N3. These values are in good agreement with those seen in 1,2-bis(methoxycarbonyl)-3-phenylguanidine, (Travlos & White, 1994), in which the length pattern is the same and the range of lengths is 1.309 (3) to 1.388 (4) Å. In N,N',N''-tris(t-butoxycarbonyl)guanidine (Feichtinger et al., 1998; ═N and C—NH groups are disordered, and the C—N distance is 1.343 Å. In the title compound, the two N—H groups form intramolecular hydrogen bonds with graph set (Etter, 1990) S(6). The hydrogen bonding leads to a fairly planar central C3N3O4 portion of the molecule, which has a mean deviation 0.019 Å from coplanarity and a maximum deviation 0.0533 (10) Å for N3.
corrected by Marsh, 2002), the CThe lone stereocenter is carbon C3, with (S) configuration, as known from starting material L-leucine. α radiation was possible for this structure, on account of the excellent quality of the crystal, the fact that it is relatively rich in O and N, the high resolution of the data, and the completeness of the set of 4545 Bijvoet pairs, which were kept separate in the While the Flack (1983) parameter is unconvincing, with a value of 0.2 (5), the Hooft et al. (2008) parameter y = 0.0 (2) has a much smaller uncertainty, and the Hooft P2(true) value is 1.000. A number of oxygen-rich compounds producing Mo data sets of similar high quality have been shown to yield similarly reliable absolute-structure results, agreeing with the known configurations (Fronczek, 2010; Lutz & van Krieken, 2010; Thompson et al., 2008).
determination based on of the light atoms in Mo KFor related structures, see: Travlos & White (1994); Feichtinger et al. (1998); Marsh (2002). For graph sets, see: Etter (1990). For
based on from light atoms, see: Hooft et al. (2008); Fronczek (2010); Lutz & van Krieken (2010); Thompson et al. (2008).Data collection: COLLECT (Nonius, 2000); cell
SCALEPACK (Otwinowski & Minor, 1997); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).C24H29N3O6 | F(000) = 968 |
Mr = 455.50 | Dx = 1.297 Mg m−3 |
Orthorhombic, P212121 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2ac 2ab | Cell parameters from 5760 reflections |
a = 7.7203 (5) Å | θ = 2.5–36.1° |
b = 14.2043 (10) Å | µ = 0.09 mm−1 |
c = 21.280 (2) Å | T = 90 K |
V = 2333.6 (3) Å3 | Fragment, colourless |
Z = 4 | 0.30 × 0.28 × 0.15 mm |
Nonius KappaCCD (with an Oxford Cryosystems Cryostream cooler) diffractometer | 9219 reflections with I > 2σ(I) |
Radiation source: fine-focus sealed tube | Rint = 0.056 |
Graphite monochromator | θmax = 36.1°, θmin = 2.8° |
ω and φ scans | h = −12→12 |
43001 measured reflections | k = −22→22 |
10411 independent reflections | l = −34→34 |
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)] = 0.043 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.101 | w = 1/[σ2(Fo2) + (0.0473P)2 + 0.6349P] where P = (Fo2 + 2Fc2)/3 |
S = 1.02 | (Δ/σ)max = 0.001 |
10411 reflections | Δρmax = 0.33 e Å−3 |
307 parameters | Δρmin = −0.28 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 4545 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.2 (5) |
C24H29N3O6 | V = 2333.6 (3) Å3 |
Mr = 455.50 | Z = 4 |
Orthorhombic, P212121 | Mo Kα radiation |
a = 7.7203 (5) Å | µ = 0.09 mm−1 |
b = 14.2043 (10) Å | T = 90 K |
c = 21.280 (2) Å | 0.30 × 0.28 × 0.15 mm |
Nonius KappaCCD (with an Oxford Cryosystems Cryostream cooler) diffractometer | 9219 reflections with I > 2σ(I) |
43001 measured reflections | Rint = 0.056 |
10411 independent reflections |
R[F2 > 2σ(F2)] = 0.043 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.101 | Δρmax = 0.33 e Å−3 |
S = 1.02 | Δρmin = −0.28 e Å−3 |
10411 reflections | Absolute structure: Flack (1983), 4545 Friedel pairs |
307 parameters | Absolute structure parameter: 0.2 (5) |
0 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 | ||
O1 | 0.58734 (12) | 0.48105 (6) | 0.79229 (4) | 0.01853 (16) | |
O2 | 0.69349 (11) | 0.37173 (6) | 0.72588 (4) | 0.01797 (15) | |
O3 | 0.66892 (11) | 0.75163 (5) | 0.55412 (3) | 0.01520 (14) | |
O4 | 0.70303 (12) | 0.64048 (5) | 0.47943 (4) | 0.01833 (15) | |
O5 | 0.57441 (13) | 0.31412 (5) | 0.54332 (4) | 0.02052 (17) | |
O6 | 0.65667 (11) | 0.35908 (5) | 0.44569 (3) | 0.01435 (13) | |
N1 | 0.55713 (12) | 0.46022 (6) | 0.62459 (4) | 0.01239 (14) | |
H1N | 0.555 (2) | 0.4008 (11) | 0.6200 (7) | 0.015* | |
N2 | 0.62092 (12) | 0.60509 (5) | 0.58336 (4) | 0.01166 (14) | |
N3 | 0.63981 (13) | 0.46856 (6) | 0.51925 (4) | 0.01316 (15) | |
H3N | 0.665 (2) | 0.5094 (11) | 0.4900 (7) | 0.016* | |
C1 | 0.66331 (18) | 0.43149 (9) | 0.84503 (5) | 0.0225 (2) | |
H1A | 0.6032 | 0.3714 | 0.8511 | 0.034* | |
H1B | 0.6519 | 0.4699 | 0.8831 | 0.034* | |
H1C | 0.7862 | 0.4197 | 0.8366 | 0.034* | |
C2 | 0.61124 (13) | 0.44220 (7) | 0.73573 (4) | 0.01164 (15) | |
C3 | 0.51657 (13) | 0.49959 (7) | 0.68598 (4) | 0.01065 (15) | |
H3 | 0.5592 | 0.5660 | 0.6876 | 0.013* | |
C4 | 0.32033 (13) | 0.49892 (7) | 0.69888 (4) | 0.01355 (16) | |
H4A | 0.2779 | 0.4334 | 0.6954 | 0.016* | |
H4B | 0.3005 | 0.5198 | 0.7427 | 0.016* | |
C5 | 0.21252 (14) | 0.56144 (7) | 0.65481 (5) | 0.01525 (17) | |
H5 | 0.2404 | 0.5437 | 0.6105 | 0.018* | |
C6 | 0.01921 (16) | 0.54251 (9) | 0.66614 (7) | 0.0256 (2) | |
H6A | −0.0103 | 0.5586 | 0.7096 | 0.038* | |
H6B | −0.0055 | 0.4758 | 0.6587 | 0.038* | |
H6C | −0.0499 | 0.5811 | 0.6374 | 0.038* | |
C7 | 0.25316 (14) | 0.66599 (7) | 0.66332 (5) | 0.01623 (18) | |
H7A | 0.1775 | 0.7033 | 0.6360 | 0.024* | |
H7B | 0.3744 | 0.6778 | 0.6522 | 0.024* | |
H7C | 0.2336 | 0.6839 | 0.7072 | 0.024* | |
C8 | 0.60582 (13) | 0.51301 (6) | 0.57593 (4) | 0.01072 (15) | |
C9 | 0.66760 (13) | 0.66107 (7) | 0.53418 (4) | 0.01203 (15) | |
C10 | 0.70649 (16) | 0.82125 (7) | 0.50644 (5) | 0.01594 (18) | |
H10A | 0.6129 | 0.8227 | 0.4747 | 0.019* | |
H10B | 0.8168 | 0.8061 | 0.4850 | 0.019* | |
C11 | 0.71972 (14) | 0.91503 (7) | 0.53912 (5) | 0.01436 (17) | |
C12 | 0.83270 (16) | 0.92721 (8) | 0.58972 (5) | 0.01901 (19) | |
H12 | 0.9022 | 0.8761 | 0.6036 | 0.023* | |
C13 | 0.84373 (17) | 1.01415 (9) | 0.61988 (6) | 0.0235 (2) | |
H13 | 0.9205 | 1.0221 | 0.6544 | 0.028* | |
C14 | 0.74245 (17) | 1.08929 (8) | 0.59950 (6) | 0.0243 (2) | |
H14 | 0.7502 | 1.1485 | 0.6201 | 0.029* | |
C15 | 0.63033 (17) | 1.07768 (7) | 0.54924 (6) | 0.0220 (2) | |
H15 | 0.5616 | 1.1290 | 0.5353 | 0.026* | |
C16 | 0.61826 (16) | 0.99065 (7) | 0.51914 (5) | 0.01785 (18) | |
H16 | 0.5406 | 0.9828 | 0.4849 | 0.021* | |
C17 | 0.61893 (14) | 0.37440 (7) | 0.50618 (5) | 0.01343 (16) | |
C18 | 0.63343 (15) | 0.26163 (7) | 0.42515 (5) | 0.01528 (18) | |
H18A | 0.5126 | 0.2412 | 0.4326 | 0.018* | |
H18B | 0.7119 | 0.2194 | 0.4489 | 0.018* | |
C19 | 0.67470 (14) | 0.25779 (6) | 0.35627 (4) | 0.01216 (15) | |
C20 | 0.55057 (14) | 0.22770 (7) | 0.31311 (5) | 0.01544 (17) | |
H20 | 0.4373 | 0.2120 | 0.3270 | 0.019* | |
C21 | 0.59258 (16) | 0.22057 (8) | 0.24956 (5) | 0.0188 (2) | |
H21 | 0.5084 | 0.1988 | 0.2204 | 0.023* | |
C22 | 0.75696 (16) | 0.24510 (8) | 0.22862 (5) | 0.0190 (2) | |
H22 | 0.7849 | 0.2410 | 0.1852 | 0.023* | |
C23 | 0.88041 (15) | 0.27570 (7) | 0.27170 (5) | 0.01767 (18) | |
H23 | 0.9928 | 0.2928 | 0.2576 | 0.021* | |
C24 | 0.84025 (14) | 0.28140 (7) | 0.33530 (5) | 0.01503 (17) | |
H24 | 0.9257 | 0.3014 | 0.3645 | 0.018* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0276 (4) | 0.0184 (3) | 0.0095 (3) | 0.0087 (3) | −0.0024 (3) | −0.0005 (3) |
O2 | 0.0190 (4) | 0.0179 (3) | 0.0170 (3) | 0.0076 (3) | 0.0007 (3) | 0.0004 (3) |
O3 | 0.0251 (4) | 0.0083 (3) | 0.0122 (3) | −0.0017 (3) | 0.0044 (3) | 0.0002 (2) |
O4 | 0.0303 (4) | 0.0128 (3) | 0.0120 (3) | −0.0029 (3) | 0.0067 (3) | −0.0006 (2) |
O5 | 0.0370 (5) | 0.0108 (3) | 0.0137 (3) | −0.0018 (3) | 0.0072 (3) | −0.0001 (3) |
O6 | 0.0222 (4) | 0.0101 (3) | 0.0107 (3) | −0.0015 (3) | 0.0039 (3) | −0.0022 (2) |
N1 | 0.0194 (4) | 0.0083 (3) | 0.0095 (3) | −0.0002 (3) | 0.0026 (3) | −0.0005 (2) |
N2 | 0.0163 (4) | 0.0084 (3) | 0.0103 (3) | −0.0011 (3) | 0.0016 (3) | 0.0001 (2) |
N3 | 0.0209 (4) | 0.0087 (3) | 0.0099 (3) | −0.0009 (3) | 0.0035 (3) | −0.0003 (2) |
C1 | 0.0282 (6) | 0.0277 (5) | 0.0115 (4) | 0.0081 (5) | −0.0040 (4) | 0.0028 (4) |
C2 | 0.0121 (4) | 0.0126 (4) | 0.0103 (3) | −0.0008 (3) | 0.0002 (3) | 0.0011 (3) |
C3 | 0.0141 (4) | 0.0096 (3) | 0.0083 (3) | 0.0009 (3) | 0.0012 (3) | 0.0000 (3) |
C4 | 0.0127 (4) | 0.0144 (4) | 0.0136 (4) | 0.0011 (3) | 0.0005 (3) | 0.0016 (3) |
C5 | 0.0156 (4) | 0.0147 (4) | 0.0154 (4) | 0.0030 (3) | −0.0035 (3) | −0.0015 (3) |
C6 | 0.0152 (5) | 0.0239 (5) | 0.0377 (7) | 0.0013 (4) | −0.0054 (5) | −0.0014 (5) |
C7 | 0.0177 (5) | 0.0139 (4) | 0.0171 (4) | 0.0043 (3) | −0.0029 (3) | −0.0012 (3) |
C8 | 0.0124 (4) | 0.0105 (3) | 0.0092 (3) | 0.0006 (3) | 0.0005 (3) | −0.0004 (3) |
C9 | 0.0128 (4) | 0.0100 (3) | 0.0132 (4) | −0.0004 (3) | 0.0006 (3) | 0.0002 (3) |
C10 | 0.0252 (5) | 0.0099 (4) | 0.0127 (4) | −0.0022 (3) | 0.0047 (4) | 0.0019 (3) |
C11 | 0.0193 (4) | 0.0094 (3) | 0.0144 (4) | −0.0018 (3) | 0.0053 (3) | 0.0004 (3) |
C12 | 0.0218 (5) | 0.0158 (4) | 0.0195 (4) | −0.0004 (4) | 0.0029 (4) | −0.0013 (4) |
C13 | 0.0238 (5) | 0.0228 (5) | 0.0239 (5) | −0.0051 (4) | 0.0040 (4) | −0.0084 (4) |
C14 | 0.0280 (6) | 0.0147 (4) | 0.0302 (6) | −0.0059 (4) | 0.0126 (5) | −0.0070 (4) |
C15 | 0.0289 (6) | 0.0111 (4) | 0.0259 (5) | 0.0028 (4) | 0.0118 (4) | 0.0016 (4) |
C16 | 0.0223 (5) | 0.0137 (4) | 0.0175 (4) | 0.0019 (4) | 0.0059 (4) | 0.0024 (3) |
C17 | 0.0180 (4) | 0.0108 (4) | 0.0115 (4) | 0.0009 (3) | 0.0024 (3) | −0.0022 (3) |
C18 | 0.0231 (5) | 0.0096 (4) | 0.0132 (4) | −0.0026 (3) | 0.0042 (3) | −0.0027 (3) |
C19 | 0.0155 (4) | 0.0097 (3) | 0.0113 (3) | 0.0005 (3) | 0.0013 (3) | −0.0017 (3) |
C20 | 0.0140 (4) | 0.0146 (4) | 0.0178 (4) | 0.0018 (3) | −0.0006 (3) | −0.0039 (3) |
C21 | 0.0219 (5) | 0.0186 (4) | 0.0158 (4) | 0.0056 (4) | −0.0070 (4) | −0.0041 (4) |
C22 | 0.0287 (6) | 0.0165 (4) | 0.0118 (4) | 0.0045 (4) | 0.0010 (4) | 0.0008 (3) |
C23 | 0.0199 (5) | 0.0169 (4) | 0.0163 (4) | −0.0009 (4) | 0.0045 (4) | 0.0015 (3) |
C24 | 0.0163 (4) | 0.0150 (4) | 0.0138 (4) | −0.0025 (3) | 0.0005 (3) | −0.0005 (3) |
O1—C2 | 1.3369 (12) | C7—H7A | 0.9800 |
O1—C1 | 1.4488 (13) | C7—H7B | 0.9800 |
O2—C2 | 1.2037 (12) | C7—H7C | 0.9800 |
O3—C9 | 1.3546 (12) | C10—C11 | 1.5061 (14) |
O3—C10 | 1.4462 (12) | C10—H10A | 0.9900 |
O4—C9 | 1.2321 (12) | C10—H10B | 0.9900 |
O5—C17 | 1.2147 (12) | C11—C16 | 1.3958 (15) |
O6—C17 | 1.3377 (12) | C11—C12 | 1.3966 (16) |
O6—C18 | 1.4626 (12) | C12—C13 | 1.3943 (16) |
N1—C8 | 1.3326 (12) | C12—H12 | 0.9500 |
N1—C3 | 1.4550 (12) | C13—C14 | 1.3923 (19) |
N1—H1N | 0.849 (16) | C13—H13 | 0.9500 |
N2—C8 | 1.3225 (12) | C14—C15 | 1.386 (2) |
N2—C9 | 1.3628 (12) | C14—H14 | 0.9500 |
N3—C17 | 1.3756 (12) | C15—C16 | 1.3954 (15) |
N3—C8 | 1.3864 (12) | C15—H15 | 0.9500 |
N3—H3N | 0.873 (16) | C16—H16 | 0.9500 |
C1—H1A | 0.9800 | C18—C19 | 1.5011 (14) |
C1—H1B | 0.9800 | C18—H18A | 0.9900 |
C1—H1C | 0.9800 | C18—H18B | 0.9900 |
C2—C3 | 1.5230 (13) | C19—C20 | 1.3944 (14) |
C3—C4 | 1.5397 (14) | C19—C24 | 1.3947 (15) |
C3—H3 | 1.0000 | C20—C21 | 1.3944 (16) |
C4—C5 | 1.5366 (14) | C20—H20 | 0.9500 |
C4—H4A | 0.9900 | C21—C22 | 1.3895 (18) |
C4—H4B | 0.9900 | C21—H21 | 0.9500 |
C5—C7 | 1.5286 (15) | C22—C23 | 1.3920 (17) |
C5—C6 | 1.5355 (17) | C22—H22 | 0.9500 |
C5—H5 | 1.0000 | C23—C24 | 1.3910 (15) |
C6—H6A | 0.9800 | C23—H23 | 0.9500 |
C6—H6B | 0.9800 | C24—H24 | 0.9500 |
C6—H6C | 0.9800 | ||
C2—O1—C1 | 116.17 (8) | O4—C9—N2 | 130.27 (9) |
C9—O3—C10 | 115.54 (8) | O3—C9—N2 | 108.40 (8) |
C17—O6—C18 | 114.50 (8) | O3—C10—C11 | 107.12 (8) |
C8—N1—C3 | 122.83 (8) | O3—C10—H10A | 110.3 |
C8—N1—H1N | 118.5 (11) | C11—C10—H10A | 110.3 |
C3—N1—H1N | 118.6 (11) | O3—C10—H10B | 110.3 |
C8—N2—C9 | 120.56 (8) | C11—C10—H10B | 110.3 |
C17—N3—C8 | 126.62 (8) | H10A—C10—H10B | 108.5 |
C17—N3—H3N | 121.8 (10) | C16—C11—C12 | 119.34 (10) |
C8—N3—H3N | 111.1 (10) | C16—C11—C10 | 120.13 (10) |
O1—C1—H1A | 109.5 | C12—C11—C10 | 120.53 (10) |
O1—C1—H1B | 109.5 | C13—C12—C11 | 120.18 (11) |
H1A—C1—H1B | 109.5 | C13—C12—H12 | 119.9 |
O1—C1—H1C | 109.5 | C11—C12—H12 | 119.9 |
H1A—C1—H1C | 109.5 | C14—C13—C12 | 120.09 (12) |
H1B—C1—H1C | 109.5 | C14—C13—H13 | 120.0 |
O2—C2—O1 | 124.94 (9) | C12—C13—H13 | 120.0 |
O2—C2—C3 | 125.25 (9) | C15—C14—C13 | 119.99 (11) |
O1—C2—C3 | 109.80 (8) | C15—C14—H14 | 120.0 |
N1—C3—C2 | 108.37 (8) | C13—C14—H14 | 120.0 |
N1—C3—C4 | 111.68 (8) | C14—C15—C16 | 120.10 (11) |
C2—C3—C4 | 110.18 (8) | C14—C15—H15 | 120.0 |
N1—C3—H3 | 108.9 | C16—C15—H15 | 120.0 |
C2—C3—H3 | 108.9 | C15—C16—C11 | 120.30 (11) |
C4—C3—H3 | 108.9 | C15—C16—H16 | 119.9 |
C5—C4—C3 | 114.87 (8) | C11—C16—H16 | 119.9 |
C5—C4—H4A | 108.5 | O5—C17—O6 | 124.96 (9) |
C3—C4—H4A | 108.5 | O5—C17—N3 | 125.94 (9) |
C5—C4—H4B | 108.5 | O6—C17—N3 | 109.10 (8) |
C3—C4—H4B | 108.5 | O6—C18—C19 | 107.47 (8) |
H4A—C4—H4B | 107.5 | O6—C18—H18A | 110.2 |
C7—C5—C6 | 110.55 (9) | C19—C18—H18A | 110.2 |
C7—C5—C4 | 112.21 (8) | O6—C18—H18B | 110.2 |
C6—C5—C4 | 109.24 (9) | C19—C18—H18B | 110.2 |
C7—C5—H5 | 108.2 | H18A—C18—H18B | 108.5 |
C6—C5—H5 | 108.2 | C20—C19—C24 | 119.53 (9) |
C4—C5—H5 | 108.2 | C20—C19—C18 | 120.56 (9) |
C5—C6—H6A | 109.5 | C24—C19—C18 | 119.88 (9) |
C5—C6—H6B | 109.5 | C19—C20—C21 | 120.08 (10) |
H6A—C6—H6B | 109.5 | C19—C20—H20 | 120.0 |
C5—C6—H6C | 109.5 | C21—C20—H20 | 120.0 |
H6A—C6—H6C | 109.5 | C22—C21—C20 | 120.35 (10) |
H6B—C6—H6C | 109.5 | C22—C21—H21 | 119.8 |
C5—C7—H7A | 109.5 | C20—C21—H21 | 119.8 |
C5—C7—H7B | 109.5 | C21—C22—C23 | 119.50 (10) |
H7A—C7—H7B | 109.5 | C21—C22—H22 | 120.2 |
C5—C7—H7C | 109.5 | C23—C22—H22 | 120.2 |
H7A—C7—H7C | 109.5 | C24—C23—C22 | 120.42 (11) |
H7B—C7—H7C | 109.5 | C24—C23—H23 | 119.8 |
N2—C8—N1 | 119.24 (8) | C22—C23—H23 | 119.8 |
N2—C8—N3 | 122.53 (8) | C23—C24—C19 | 120.10 (10) |
N1—C8—N3 | 118.24 (8) | C23—C24—H24 | 119.9 |
O4—C9—O3 | 121.32 (9) | C19—C24—H24 | 119.9 |
C1—O1—C2—O2 | −1.94 (16) | O3—C10—C11—C12 | 54.29 (13) |
C1—O1—C2—C3 | 177.18 (9) | C16—C11—C12—C13 | 0.00 (16) |
C8—N1—C3—C2 | −132.15 (10) | C10—C11—C12—C13 | −179.77 (10) |
C8—N1—C3—C4 | 106.31 (11) | C11—C12—C13—C14 | −0.20 (18) |
O2—C2—C3—N1 | −5.64 (14) | C12—C13—C14—C15 | 0.08 (18) |
O1—C2—C3—N1 | 175.24 (8) | C13—C14—C15—C16 | 0.24 (18) |
O2—C2—C3—C4 | 116.82 (11) | C14—C15—C16—C11 | −0.45 (17) |
O1—C2—C3—C4 | −62.30 (11) | C12—C11—C16—C15 | 0.33 (16) |
N1—C3—C4—C5 | −64.38 (11) | C10—C11—C16—C15 | −179.91 (10) |
C2—C3—C4—C5 | 175.13 (8) | C18—O6—C17—O5 | 2.47 (16) |
C3—C4—C5—C7 | −65.68 (11) | C18—O6—C17—N3 | −177.91 (9) |
C3—C4—C5—C6 | 171.35 (9) | C8—N3—C17—O5 | −3.52 (19) |
C9—N2—C8—N1 | −178.87 (9) | C8—N3—C17—O6 | 176.87 (10) |
C9—N2—C8—N3 | 1.53 (15) | C17—O6—C18—C19 | 177.95 (9) |
C3—N1—C8—N2 | 1.03 (15) | O6—C18—C19—C20 | −120.63 (10) |
C3—N1—C8—N3 | −179.35 (9) | O6—C18—C19—C24 | 61.55 (12) |
C17—N3—C8—N2 | −176.29 (10) | C24—C19—C20—C21 | 0.56 (15) |
C17—N3—C8—N1 | 4.11 (16) | C18—C19—C20—C21 | −177.26 (9) |
C10—O3—C9—O4 | 2.71 (15) | C19—C20—C21—C22 | −1.28 (16) |
C10—O3—C9—N2 | −176.60 (9) | C20—C21—C22—C23 | 0.85 (16) |
C8—N2—C9—O4 | −0.78 (18) | C21—C22—C23—C24 | 0.28 (16) |
C8—N2—C9—O3 | 178.44 (9) | C22—C23—C24—C19 | −0.99 (16) |
C9—O3—C10—C11 | −174.34 (9) | C20—C19—C24—C23 | 0.56 (15) |
O3—C10—C11—C16 | −125.47 (10) | C18—C19—C24—C23 | 178.40 (9) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O5 | 0.849 (16) | 2.051 (16) | 2.7047 (11) | 133.3 (14) |
N3—H3N···O4 | 0.873 (16) | 1.898 (16) | 2.6306 (11) | 140.4 (14) |
Experimental details
Crystal data | |
Chemical formula | C24H29N3O6 |
Mr | 455.50 |
Crystal system, space group | Orthorhombic, P212121 |
Temperature (K) | 90 |
a, b, c (Å) | 7.7203 (5), 14.2043 (10), 21.280 (2) |
V (Å3) | 2333.6 (3) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.30 × 0.28 × 0.15 |
Data collection | |
Diffractometer | Nonius KappaCCD (with an Oxford Cryosystems Cryostream cooler) |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 43001, 10411, 9219 |
Rint | 0.056 |
(sin θ/λ)max (Å−1) | 0.829 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.043, 0.101, 1.02 |
No. of reflections | 10411 |
No. of parameters | 307 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.33, −0.28 |
Absolute structure | Flack (1983), 4545 Friedel pairs |
Absolute structure parameter | 0.2 (5) |
Computer programs: COLLECT (Nonius, 2000), DENZO and SCALEPACK (Otwinowski & Minor, 1997), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1N···O5 | 0.849 (16) | 2.051 (16) | 2.7047 (11) | 133.3 (14) |
N3—H3N···O4 | 0.873 (16) | 1.898 (16) | 2.6306 (11) | 140.4 (14) |
Acknowledgements
The purchase of the diffractometer at Louisiana State University was made possible by grant No. LEQSF(1999–2000)-ENH-TR-13, administered by the Louisiana Board of Regents. We thank MingZhou Zhou for helpful discussions and Melissa Topper for assistance with crystallization.
References
Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115–119. Web of Science CrossRef CAS IUCr Journals Google Scholar
Etter, M. C. (1990). Acc. Chem. Res. 23, 120–126. CrossRef CAS Web of Science Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Feichtinger, K., Sings, H. L., Baker, T. J., Matthews, K. & Goodman, M. (1998). J. Org. Chem. 63, 8432–8439. Web of Science CSD CrossRef CAS Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Fronczek, F. (2010). ACA Annual Meeting, Chicago, Illinois, USA. Abstract 07.06.5. Google Scholar
Hooft, R. W. W., Straver, L. H. & Spek, A. L. (2008). J. Appl. Cryst. 41, 96–103. Web of Science CrossRef CAS IUCr Journals Google Scholar
Lutz, M. & van Krieken, J. (2010). Acta Cryst. C66, o401–o405. Web of Science CSD CrossRef IUCr Journals Google Scholar
Marsh, R. E. (2002). Acta Cryst. B58, 893–899. CSD CrossRef CAS IUCr Journals Google Scholar
Nonius (2000). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307-326. New York: Academic Press. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Thompson, A. L., Watkin, D. J., Gal, Z. A., Jones, L., Hollinshead, J., Jenkinson, S. F., Fleet, G. W. J. & Nash, R. J. (2008). Acta Cryst. C64, o649–o652. Web of Science CSD CrossRef IUCr Journals Google Scholar
Travlos, S. D. & White, J. (1994). Acta Cryst. C50, 1631–1632. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
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Molecules used as drugs frequently contain heterocyclic subunits, and substituted guanidine or amidine compounds are very important intermediates in the synthesis of many heterocyclic compounds. However, substituted guanidines and amidine compounds themselves can be difficult to synthesize. Thus, synthesis of substituted guanidines is important and interesting. One possible route to these compounds is to use 1,3-bis(benzyloxycarbonyl)-2-methyl-2-thiopseudourea, which has a good leaving group and L-leucine methyl ester hydrochloride, which is a good nucleophile. Reaction of these starting materials led to successful synthesis of the chiral title compound, which was confirmed by crystal structure determination.
The structure, shown in Figure 1, has a guanidine at its core. The three C—N distances of the guanidine vary from 1.3225 (12) to 1.3864 (12) Å, with the shortest being the formal double bond to the unprotonated N atom N2 and the longest being to the other carbamate N atom N3. These values are in good agreement with those seen in 1,2-bis(methoxycarbonyl)-3-phenylguanidine, (Travlos & White, 1994), in which the length pattern is the same and the range of lengths is 1.309 (3) to 1.388 (4) Å. In N,N',N''-tris(t-butoxycarbonyl)guanidine (Feichtinger et al., 1998; space group corrected by Marsh, 2002), the C═N and C—NH groups are disordered, and the C—N distance is 1.343 Å. In the title compound, the two N—H groups form intramolecular hydrogen bonds with graph set (Etter, 1990) S(6). The hydrogen bonding leads to a fairly planar central C3N3O4 portion of the molecule, which has a mean deviation 0.019 Å from coplanarity and a maximum deviation 0.0533 (10) Å for N3.
The lone stereocenter is carbon C3, with (S) configuration, as known from starting material L-leucine. Absolute configuration determination based on resonant scattering of the light atoms in Mo Kα radiation was possible for this structure, on account of the excellent quality of the crystal, the fact that it is relatively rich in O and N, the high resolution of the data, and the completeness of the set of 4545 Bijvoet pairs, which were kept separate in the refinement. While the Flack (1983) parameter is unconvincing, with a value of 0.2 (5), the Hooft et al. (2008) parameter y = 0.0 (2) has a much smaller uncertainty, and the Hooft P2(true) value is 1.000. A number of oxygen-rich compounds producing Mo data sets of similar high quality have been shown to yield similarly reliable absolute-structure results, agreeing with the known configurations (Fronczek, 2010; Lutz & van Krieken, 2010; Thompson et al., 2008).