Methyl 3-carb­oxy-7-(tert-butoxy­carbonyl)-4,7-diaza­hepta­noate

In the mol­ecule of the title compound, C₁₂H₂₂N₂O₆, the dihedral angle between the planar carbamo­yloxy and ester C—COO units is 22.23 (3)°. In the crystal structure, inter­molecular O—H...N and N—H...O hydrogen bonds link the mol­ecules into chains.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.057
• wR factor = 0.129
• Data-to-parameter ratio = 8.5

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT340_ALERT_3_C Low Bond Precision on C-C Bonds (x 1000) Ang ...          7

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           25.96
           From the CIF: _reflns_number_total               1540
           Count of symmetry unique reflns         1540
           Completeness (_total/calc)            100.00%
           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
PLAT792_ALERT_1_G Check the Absolute Configuration of C8     = ...          R

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   2 ALERT level G = General alerts; check

   1 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
   1 ALERT type 3 Indicator that the structure quality may be low
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

In the process of synthesis, we obtained the title compound, (I), and we herein report its crystal structure.

In the molecule of (I), (Fig. 1), the bond lengths and angles are within normal ranges (Allen et al., 1987). The dihedral angle between the planar (O1/O2/N1/C5) and (O5/O6/C10/C11) units is 22.23 (3)°.

In the crystal structure, the intermolecular O—H···N and N—H···O hydrogen bonds (Table 1) link the molecules into chains, in which they may be effective in the stabilization of the structure.

Related literature

For general background, see: Allen et al. (1987).

S2. Experimental

For the preparation of the title compound, maleic anhydride (10 g, 100 mmol) and methanol (50 ml) were added into a four-necked round-bottom flask fitted with a mechanical stirrer, dropping funnel and thermometer. After the mixture was refluxed in a water bath for 30 min, excess methanol was distilled off. Triethylamine (20 ml) was added to the reside, cooled in ice, and stirred very slowly. Then, N-(tert-butoxycarbonyl)-1,2-ethane diamine (16 g, 100 mmol) was added, and the mixture was stirred in a water bath for 2 h. The mixture was filtrated and washed twice with hot acetone (100 ml). Crystals of (I) suitable for X-ray analsyis were obtained by slow evaporation of methanol (10 ml) (yield; 23.5 g, 72%, m.p. 454 K).

S3. Refinement

H atoms were positioned geometrically, with O—H = 0.82 Å (for OH), N—H = 0.86 Å (for NH) and C—H = 0.98, 0.97 and 0.96 Å for methine, methylene and methyl H, respectively, and constrained to ride on their parent atoms, with U_iso(H) = xU_eq(C,N,O), where x = 1.5 for NH and methyl H atoms, and x = 1.2 for all other H atoms.

Computing details

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
	Fig. 2. A packing diagram for (I). Hydrogen bonds are shown as dashed lines.

Methyl 3-carboxy-7-(tert-butoxycarbonyl)-4,7-diazaheptanoate

Crystal data

C12H22N2O6	Dx = 1.312 Mg m^−3
Mr = 290.32	Melting point: 454 K
Orthorhombic, Pca21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2ac	Cell parameters from 25 reflections
a = 10.824 (2) Å	θ = 9–12°
b = 15.204 (3) Å	µ = 0.11 mm^−1
c = 8.9300 (18) Å	T = 298 K
V = 1469.6 (5) Å^3	Block, colourless
Z = 4	0.40 × 0.30 × 0.10 mm
F(000) = 624

Data collection

Enraf–Nonius CAD-4 diffractometer	984 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.042
Graphite monochromator	θmax = 26.0°, θmin = 1.3°
ω/2θ scans	h = 0→13
Absorption correction: ψ scan (North et al., 1968)	k = 0→18
Tmin = 0.954, Tmax = 0.990	l = 0→10
1921 measured reflections	3 standard reflections every 200 reflections
1540 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.057	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.129	H-atom parameters constrained
S = 0.90	w = 1/[σ^2(Fo^2) + (0.059P)^2 + 3.5659P] where P = (Fo^2 + 2Fc^2)/3
1540 reflections	(Δ/σ)max < 0.001
182 parameters	Δρmax = 0.23 e Å^−3
0 restraints	Δρmin = −0.13 e Å^−3

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.9191 (4)	0.8093 (3)	0.6834 (6)	0.0502 (12)
O2	0.9209 (5)	0.8738 (3)	0.4545 (6)	0.0675 (15)
O3	1.1376 (4)	0.4304 (3)	0.1506 (6)	0.0587 (15)
H3	1.2097	0.4253	0.1777	0.088*
O4	1.1218 (3)	0.5130 (3)	0.3553 (5)	0.0538 (12)
O5	0.8910 (4)	0.3791 (3)	0.4610 (6)	0.0600 (13)
O6	0.7747 (4)	0.2899 (3)	0.3195 (6)	0.0562 (13)
N1	0.8734 (5)	0.7303 (4)	0.4871 (7)	0.0542 (15)
H1	0.8748	0.6869	0.5487	0.065*
N2	0.8842 (4)	0.5550 (3)	0.3022 (6)	0.0385 (13)
H2	0.8391	0.5417	0.3782	0.046*
C1	0.8483 (4)	0.9585 (4)	0.7424 (5)	0.072 (3)
H1B	0.8520	0.9787	0.6407	0.108*
H1C	0.8605	1.0072	0.8091	0.108*
H1A	0.7690	0.9325	0.7610	0.108*
C2	0.9464 (4)	0.8585 (4)	0.9272 (5)	0.070 (3)
H2B	1.0113	0.8162	0.9403	0.105*
H2C	0.8682	0.8314	0.9484	0.105*
H2A	0.9591	0.9070	0.9944	0.105*
C3	1.0736 (4)	0.9238 (4)	0.7211 (4)	0.070 (2)
H3A	1.0700	0.9451	0.6200	0.105*
H3B	1.1318	0.8763	0.7272	0.105*
H3C	1.0991	0.9706	0.7864	0.105*
C4	0.9472 (4)	0.8915 (4)	0.7681 (5)	0.055 (2)
C5	0.9062 (4)	0.8111 (4)	0.5360 (5)	0.0466 (17)
C6	0.8359 (4)	0.7149 (4)	0.3337 (4)	0.065 (2)
H6A	0.8419	0.7698	0.2786	0.078*
H6B	0.7499	0.6969	0.3328	0.078*
C7	0.9117 (4)	0.6461 (4)	0.2543 (4)	0.0552 (19)
H7A	0.8972	0.6509	0.1474	0.066*
H7B	0.9986	0.6579	0.2720	0.066*
C8	0.9439 (4)	0.4897 (4)	0.2033 (4)	0.0359 (14)
H8	0.9422	0.5149	0.1023	0.043*
C9	1.0804 (4)	0.4764 (4)	0.2425 (5)	0.0365 (14)
C10	0.8706 (4)	0.4040 (4)	0.1954 (4)	0.0362 (14)
H10A	0.7907	0.4162	0.1507	0.043*
H10B	0.9209	0.3647	0.1354	0.043*
C11	0.8504 (4)	0.3591 (4)	0.3417 (4)	0.0420 (15)
C12	0.7384 (4)	0.2387 (4)	0.4468 (5)	0.070 (2)
H12A	0.8051	0.2366	0.5175	0.105*
H12B	0.7182	0.1801	0.4152	0.105*
H12C	0.6674	0.2652	0.4931	0.105*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.046 (3)	0.045 (2)	0.059 (3)	−0.009 (2)	−0.003 (3)	−0.002 (2)
O2	0.086 (4)	0.050 (3)	0.067 (4)	−0.005 (3)	0.000 (3)	0.013 (3)
O3	0.025 (2)	0.052 (3)	0.099 (4)	0.002 (2)	0.016 (3)	−0.012 (3)
O4	0.0221 (18)	0.092 (4)	0.047 (3)	−0.010 (2)	−0.008 (2)	0.009 (3)
O5	0.049 (3)	0.076 (3)	0.055 (3)	−0.013 (2)	−0.007 (3)	−0.005 (3)
O6	0.049 (3)	0.058 (3)	0.062 (3)	−0.015 (2)	0.010 (3)	−0.010 (3)
N1	0.061 (4)	0.048 (3)	0.053 (4)	0.008 (3)	−0.009 (3)	−0.006 (3)
N2	0.020 (2)	0.050 (3)	0.045 (3)	0.001 (2)	−0.001 (2)	0.002 (3)
C1	0.051 (5)	0.067 (5)	0.102 (9)	0.024 (4)	−0.010 (6)	−0.022 (6)
C2	0.049 (4)	0.087 (7)	0.074 (6)	−0.011 (4)	0.004 (4)	−0.028 (5)
C3	0.045 (4)	0.061 (4)	0.104 (7)	−0.006 (3)	−0.008 (5)	−0.008 (5)
C4	0.034 (3)	0.047 (4)	0.082 (6)	0.002 (3)	−0.007 (4)	−0.018 (4)
C5	0.027 (3)	0.061 (5)	0.052 (4)	0.005 (3)	0.003 (3)	0.008 (4)
C6	0.071 (5)	0.067 (5)	0.059 (5)	0.025 (4)	−0.011 (5)	−0.002 (5)
C7	0.076 (5)	0.049 (4)	0.041 (4)	0.011 (4)	−0.002 (4)	0.006 (3)
C8	0.018 (2)	0.045 (3)	0.044 (4)	0.001 (2)	0.001 (3)	0.000 (3)
C9	0.018 (2)	0.047 (3)	0.044 (4)	0.005 (3)	−0.001 (3)	0.002 (3)
C10	0.021 (3)	0.052 (3)	0.036 (3)	−0.001 (3)	−0.001 (3)	−0.008 (3)
C11	0.020 (3)	0.052 (4)	0.054 (4)	0.003 (3)	0.002 (3)	−0.016 (4)
C12	0.058 (4)	0.070 (4)	0.083 (6)	−0.004 (4)	0.029 (5)	−0.002 (5)

Geometric parameters (Å, º)

O1—C5	1.324 (8)	C2—H2C	0.9600
O1—C4	1.492 (8)	C2—H2A	0.9600
O2—C5	1.211 (8)	C3—C4	1.513 (9)
O3—C9	1.244 (7)	C3—H3A	0.9600
O3—H3	0.8200	C3—H3B	0.9600
O4—C9	1.235 (7)	C3—H3C	0.9600
O5—C11	1.192 (8)	C6—C7	1.508 (9)
O6—C11	1.348 (7)	C6—H6A	0.9700
O6—C12	1.433 (8)	C6—H6B	0.9700
N1—C5	1.351 (8)	C7—H7A	0.9700
N1—C6	1.448 (10)	C7—H7B	0.9700
N1—H1	0.8600	C8—C9	1.531 (7)
N2—C8	1.477 (7)	C8—C10	1.528 (7)
N2—C7	1.479 (8)	C8—H8	0.9800
N2—H2	0.8600	C10—C11	1.491 (9)
C1—C4	1.495 (9)	C10—H10A	0.9700
C1—H1B	0.9600	C10—H10B	0.9701
C1—H1C	0.9600	C12—H12A	0.9600
C1—H1A	0.9600	C12—H12B	0.9600
C2—C4	1.507 (11)	C12—H12C	0.9600
C2—H2B	0.9600
C5—O1—C4	120.5 (6)	N1—C6—C7	113.8 (6)
C9—O3—H3	109.5	N1—C6—H6A	108.8
C11—O6—C12	118.3 (6)	C7—C6—H6A	108.8
C5—N1—C6	121.8 (6)	N1—C6—H6B	108.8
C5—N1—H1	119.1	C7—C6—H6B	108.8
C6—N1—H1	119.1	H6A—C6—H6B	107.7
C8—N2—C7	111.6 (5)	N2—C7—C6	113.8 (6)
C8—N2—H2	124.2	N2—C7—H7A	108.8
C7—N2—H2	124.2	C6—C7—H7A	108.8
C4—C1—H1B	109.5	N2—C7—H7B	108.8
C4—C1—H1C	109.5	C6—C7—H7B	108.8
H1B—C1—H1C	109.5	H7A—C7—H7B	107.7
C4—C1—H1A	109.5	N2—C8—C9	112.0 (5)
H1B—C1—H1A	109.5	N2—C8—C10	111.9 (4)
H1C—C1—H1A	109.5	C9—C8—C10	113.5 (5)
C4—C2—H2B	109.5	N2—C8—H8	106.3
C4—C2—H2C	109.5	C9—C8—H8	106.3
H2B—C2—H2C	109.5	C10—C8—H8	106.3
C4—C2—H2A	109.5	O4—C9—O3	127.6 (5)
H2B—C2—H2A	109.5	O4—C9—C8	118.5 (5)
H2C—C2—H2A	109.5	O3—C9—C8	113.9 (6)
C4—C3—H3A	109.5	C11—C10—C8	115.2 (5)
C4—C3—H3B	109.5	C11—C10—H10A	108.5
H3A—C3—H3B	109.5	C8—C10—H10A	108.6
C4—C3—H3C	109.5	C11—C10—H10B	106.5
H3A—C3—H3C	109.5	C8—C10—H10B	105.1
H3B—C3—H3C	109.5	H10A—C10—H10B	113.0
O1—C4—C1	110.3 (6)	O5—C11—O6	123.7 (7)
O1—C4—C2	101.5 (6)	O5—C11—C10	127.8 (5)
C1—C4—C2	111.5 (7)	O6—C11—C10	108.5 (6)
O1—C4—C3	108.4 (6)	O6—C12—H12A	109.5
C1—C4—C3	112.5 (6)	O6—C12—H12B	109.5
C2—C4—C3	112.0 (6)	H12A—C12—H12B	109.5
O2—C5—O1	126.9 (7)	O6—C12—H12C	109.5
O2—C5—N1	123.8 (7)	H12A—C12—H12C	109.5
O1—C5—N1	109.3 (6)	H12B—C12—H12C	109.5
C5—O1—C4—C1	58.8 (9)	C7—N2—C8—C10	−150.7 (5)
C5—O1—C4—C2	177.1 (6)	N2—C8—C9—O4	6.5 (8)
C5—O1—C4—C3	−64.9 (7)	C10—C8—C9—O4	−121.5 (6)
C4—O1—C5—O2	4.1 (10)	N2—C8—C9—O3	−171.6 (5)
C4—O1—C5—N1	−176.0 (5)	C10—C8—C9—O3	60.5 (7)
C6—N1—C5—O2	−8.8 (10)	N2—C8—C10—C11	−58.4 (6)
C6—N1—C5—O1	171.2 (6)	C9—C8—C10—C11	69.6 (6)
C5—N1—C6—C7	123.3 (7)	C12—O6—C11—O5	1.6 (8)
C8—N2—C7—C6	169.8 (5)	C12—O6—C11—C10	−177.6 (5)
N1—C6—C7—N2	74.1 (8)	C8—C10—C11—O5	−5.2 (8)
C7—N2—C8—C9	80.5 (6)	C8—C10—C11—O6	173.9 (4)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O3—H3···N2^i	0.82	2.21	3.001 (6)	161
N1—H1···O3^ii	0.86	2.01	2.849 (8)	166
N2—H2···O3^ii	0.86	2.48	3.128 (8)	132
N2—H2···O4^iii	0.86	2.50	3.060 (6)	123

Symmetry codes: (i) x+1/2, −y+1, z; (ii) −x+2, −y+1, z+1/2; (iii) x−1/2, −y+1, z.