organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Di­methyl 2-(amino­methyl­ene)malonate

aInstitute of Physical Chemistry and Chemical Physics, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, SK-812 37 Bratislava, Slovak Republic, and bInstitute of Organic Chemistry, Catalysis and Petrochemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, Radlinského 9, Bratislava 81237, Slovak Republic
*Correspondence e-mail: martin.grof@stuba.sk

(Received 24 April 2008; accepted 30 April 2008; online 7 May 2008)

In the title compound, C6H9NO4, which is an example of a push–pull alkene, N—H⋯O inter­actions stabilize the crystal structure.

Related literature

For related literature, see: Bouzard (1990[Bouzard, D. (1990). Recent Progress in the Chemical Synthesis of Antibiotics, p. 249. München: Springer-Verlag.]); Chemla & Zyss (1987[Chemla, D. & Zyss, J. (1987). Optical Properties of Organic Molecules and Crystals, Vol. 1, pp. 23-187. New York: Academic Press.]); Cook (1969[Cook, A. G. (1969). Enamines: Syntheses, Structure and Reactions. New York: Marcel Dekker.]); Freeman (1981[Freeman, F. (1981). LONZA Reaction of Malononitrile Derivatives, p. 925. Stuttgart: Georg Thieme Verlag.]); Nalwa et al. (1997[Nalwa, H. S., Watanabe, T. & Miyata, S. (1997). Nonlinear Optics of Organic Molecules and Polymers, pp. 87-329. Boca Ranton: CRC Press.]); Shmueli et al. (1973[Shmueli, U., Shanan-Atidi, H., Horwitz, H. & Shvo, Y. (1973). J. Chem. Soc. Perkin Trans. 2, pp. 657-662.]).

[Scheme 1]

Experimental

Crystal data
  • C6H9NO4

  • Mr = 159.14

  • Monoclinic, P 21 /c

  • a = 9.3410 (19) Å

  • b = 6.9000 (14) Å

  • c = 11.725 (2) Å

  • β = 97.58 (3)°

  • V = 749.1 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.12 mm−1

  • T = 100 K

  • 0.43 × 0.27 × 0.06 mm

Data collection
  • Oxford Diffraction GEMINI R diffractometer

  • Absorption correction: analytical (CrysAlis RED; Oxford Diffraction, 2006[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]) Tmin = 0.892, Tmax = 0.998

  • 14185 measured reflections

  • 1368 independent reflections

  • 841 reflections with I > 2σ(I)

  • Rint = 0.089

Refinement
  • R[F2 > 2σ(F2)] = 0.091

  • wR(F2) = 0.261

  • S = 0.99

  • 1368 reflections

  • 102 parameters

  • H-atom parameters constrained

  • Δρmax = 0.62 e Å−3

  • Δρmin = −0.38 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1B⋯O1 0.86 2.02 2.638 (2) 128
N1—H1A⋯O2i 0.86 2.02 2.848 (2) 161
Symmetry code: (i) x, y+1, z.

Data collection: CrysAlis CCD (Oxford Diffraction, 2006[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]); cell refinement: CrysAlis CCD; data reduction: CrysAlis RED (Oxford Diffraction, 2006[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: DIAMOND (Brandenburg, 1998[Brandenburg, K. (1998). DIAMOND. Crystal Impact GbR, Bonn, Germany.]); software used to prepare material for publication: enCIFer (Allen et al., 2004[Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335-338.]).

Supporting information


Comment top

The title compound (I), aminomethylene-malonic acid dimethyl ester belongs to the family of so-called push-pull ethylenes. Push-pull ethylenes with the general formula R1X—CR2=CR3R4 are highly reactive organic compounds with electron donor groups at one end and strong electron acceptor groups at the other end of ethylenic C=C double bond. Very often R2 = H and for X = NH or NR1 and X = O as the electron donor groups R1 can be hydrogen, alkyl, cycloalkyl, aryl or hetero(aryl) groups. On the other side as the electron acceptors R3, R4 are groups such as –CN, –COR, –COOR, –SO2CH3, and –NO2. Mainly enamines (X = NH, NR1) are frequently used as reactants or intermediates in chemical syntheses of drugs, polymers and dyes (Bouzard et al., 1990, Cook et al., 1969). But also alkoxymethylenes (X = O) are often used in organic synthesis (Freeman et al., 1981).

Due to the opposite character of the substituents, the olefinic C=C double bond order is reduced and accompanied by increased bond orders of bonds between the olefinic carbon atoms and their electron donor and electron acceptor groups. This leads to the substantial decrease of the rotational barrier about the C=C double bond and to the increase of an analogues barrier about the adjacent bonds. These changes are connected with the separation of positive and negative charges and electron delocalization within the π-electron system. Such compounds belong to the most developed structures in the search for new compounds with non-linear optics responses (Nalwa et al., 1997, Chemla et al., 1987).

The study of a similar compound, dimethyl-(dimethylaminomethylene)-malonate, has been done (Shmueli et al., 1973). This study revealed that dimethyl-(dimethylaminomethylene)-malonate exists in solid phase as ZE conformer (Z denotes towards to C=C double bond orientation of the carbonyl oxygen in trans position; E denotes away from C=C double bond orientation of the carbonyl oxygen in cis position). The study of aminomethylene-malonic acid dimethyl ester revealed that this compound exists in solid phase as EZ conformer. The =C—N bond length of 1.301 (4)Å in the title compound is somewhat shorter than in the case of dimethyl-(dimethylaminomethylene)-malonate (1.337 Å). The C=C bond length of 1.385 (5)Å is slightly longer than in the case of dimethyl-(dimethylaminomethylene)-malonate (1.380 Å). The =C—C trans and cis bond lengths are 1.470 (4)/1.456 (5)Å, respectively in the title compound and 1.442/1.488 Å in dimethyl-(dimethylaminomethylene)-malonate.

Related literature top

For related literature, see: Bouzard (1990); Chemla & Zyss (1987); Cook (1969); Freeman (1981); Nalwa et al. (1997); Shmueli et al. (1973).

Experimental top

To dimethyl 3-methoxymethylenemalonate (1.74 g, 10 mmol) in methanol (10 ml), an aqueous solution of ammonia (12 mmol) was added dropwise (amount according to concentration and density) over a period of 30 min with stirring. The slightly warmed mixture was stirred overnight at room temperature. The reaction mixture was then briefly heated to reflux (ca. 20 min). After ensuring that no starting derivative remained (thin-layer chromatography; Silufol 254, Kavalier Czechoslovakia; eluent chloroform-methanol 10:1 v/v, detection UV light 254 nm), the reaction mixture was evaporated on a vacuum evaporator and chromatographed on silica gel (eluent dichloromethane-methanol 10:1 v/v). Obtained product was recrystallized from minimal amount of chloroform and n-hexane mixture in refrigerator.

The solid phase mid-IR vibrational spectrum was recorded with a Nicolet model NEXUS 470 FTIR spectrometer at room temperature. The measurement was performed after mixing the powdered sample with KBr into a pellet.

The mid-IR vibrational frequencies of aminomethylene-malonic acid dimethyl ester are (in cm-1): 3460 w; 3358 s; 3296 vw; 3271 vw; 3222 s; 3135 w, sh; 3025 m; 3017 vw, sh; 2993 vw; 2962 m; 2924 vw; 2907 vw; 1683 vs; 1658 vs; 1637 vs; 1576 vw, sh; 1534 m; 1507 s; 1499 s; 1474 vw, sh; 1461 w, sh; 1440 s; 1433 w, sh; 1373 s; 1331 s; 1293 w; 1286 s; 1221 s; 1193 m; 1176 w, sh; 1150 w, sh; 1141 s; 1070 s, b; 1033 w; 982 m; 942 w; 828 w; 822 m; 783 s; 772 w; 750 vw; 715 s, b; 669 w; 649 w, b; 617 m, sh, b; 589 s; 480 s; 440 m.

Refinement top

All H atoms were positioned geometrically and allowed to ride on their corresponding parent atoms at distances of Cmethyl-H = 0.96Å, Caromatic-H = 0.93Å and N-H =0.86 Å, with Uiso(H) = 1.2Ueq(C,N) or Uiso(H) = 1.5Ueq(Cmethyl). Methyl groups were allowed to rotate but not to tip.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis CCD (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXS97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg, 1998); software used to prepare material for publication: enCIFer (Allen et al., 2004).

Figures top
[Figure 1] Fig. 1. The atom-numbering scheme of aminomethylene-malonic acid dimethyl ester. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. Packing diagram of aminomethylene-malonic acid dimethyl ester. Hydrogen-bond interactions are indicated by dashed lines.
Dimethyl 2-(aminomethylene)malonate top
Crystal data top
C6H9NO4F(000) = 336
Mr = 159.14Dx = 1.411 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 2135 reflections
a = 9.3410 (19) Åθ = 3.4–29.6°
b = 6.9000 (14) ŵ = 0.12 mm1
c = 11.725 (2) ÅT = 100 K
β = 97.58 (3)°Block, colorless
V = 749.1 (3) Å30.43 × 0.27 × 0.06 mm
Z = 4
Data collection top
Oxford Diffraction GEMINI R
diffractometer
1368 independent reflections
Radiation source: fine-focus sealed tube841 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.089
Rotation method data acquisition using ω and ϕ scansθmax = 25.3°, θmin = 4.2°
Absorption correction: analytical
(CrysAlis RED; Oxford Diffraction, 2006)
h = 1011
Tmin = 0.892, Tmax = 0.998k = 88
14185 measured reflectionsl = 1414
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.091Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.261H-atom parameters constrained
S = 0.99 w = 1/[σ2(Fo2) + (0.1927P)2]
where P = (Fo2 + 2Fc2)/3
1368 reflections(Δ/σ)max = 0.005
102 parametersΔρmax = 0.62 e Å3
0 restraintsΔρmin = 0.38 e Å3
Crystal data top
C6H9NO4V = 749.1 (3) Å3
Mr = 159.14Z = 4
Monoclinic, P21/cMo Kα radiation
a = 9.3410 (19) ŵ = 0.12 mm1
b = 6.9000 (14) ÅT = 100 K
c = 11.725 (2) Å0.43 × 0.27 × 0.06 mm
β = 97.58 (3)°
Data collection top
Oxford Diffraction GEMINI R
diffractometer
1368 independent reflections
Absorption correction: analytical
(CrysAlis RED; Oxford Diffraction, 2006)
841 reflections with I > 2σ(I)
Tmin = 0.892, Tmax = 0.998Rint = 0.089
14185 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0910 restraints
wR(F2) = 0.261H-atom parameters constrained
S = 0.99Δρmax = 0.62 e Å3
1368 reflectionsΔρmin = 0.38 e Å3
102 parameters
Special details top

Experimental. face-indexed (CrysAlis RED; Oxford Diffraction, 2006)

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
xyzUiso*/Ueq
O40.9175 (3)0.2420 (3)0.85543 (19)0.0639 (9)
O20.8250 (3)0.0207 (4)0.92664 (19)0.0657 (9)
C30.8357 (3)0.1536 (5)0.9256 (3)0.0475 (9)
N10.7287 (3)0.6345 (4)1.0263 (3)0.0648 (10)
H1B0.67170.61271.07680.078*
H1A0.74860.75171.00890.078*
C20.7644 (3)0.2942 (5)0.9935 (3)0.0460 (9)
C40.7847 (4)0.4902 (5)0.9761 (3)0.0511 (9)
H4A0.84550.52250.92220.061*
C50.9912 (5)0.1154 (5)0.7845 (3)0.0685 (12)
H5C1.04550.19160.73680.082*
H5B0.92160.03840.73680.082*
H5A1.05550.03190.83270.082*
O10.6120 (3)0.3524 (4)1.1347 (2)0.0773 (10)
O30.6559 (3)0.0457 (3)1.0934 (2)0.0594 (8)
C10.6714 (4)0.2365 (5)1.0780 (3)0.0515 (10)
C60.5661 (4)0.0100 (6)1.1793 (3)0.0705 (12)
H6C0.56000.14871.18240.085*
H6B0.47110.04331.15960.085*
H6A0.60750.03851.25310.085*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O40.0949 (19)0.0289 (14)0.0785 (17)0.0010 (12)0.0514 (14)0.0019 (11)
O20.094 (2)0.0233 (15)0.0884 (18)0.0009 (11)0.0449 (15)0.0022 (11)
C30.065 (2)0.027 (2)0.0544 (18)0.0036 (14)0.0236 (16)0.0017 (13)
N10.090 (2)0.0235 (17)0.088 (2)0.0033 (14)0.0392 (18)0.0022 (14)
C20.057 (2)0.0255 (17)0.0580 (18)0.0039 (14)0.0172 (16)0.0018 (14)
C40.067 (2)0.0299 (19)0.0601 (18)0.0043 (15)0.0210 (17)0.0008 (15)
C50.099 (3)0.037 (2)0.079 (2)0.0036 (19)0.049 (2)0.0008 (18)
O10.111 (2)0.0312 (15)0.104 (2)0.0012 (13)0.0689 (17)0.0028 (13)
O30.0900 (18)0.0217 (14)0.0756 (15)0.0054 (10)0.0445 (13)0.0026 (10)
C10.062 (2)0.030 (2)0.066 (2)0.0002 (14)0.0221 (17)0.0043 (14)
C60.101 (3)0.039 (2)0.081 (2)0.012 (2)0.047 (2)0.0024 (19)
Geometric parameters (Å, º) top
O4—C31.342 (4)C5—H5C0.9600
O4—C51.442 (4)C5—H5B0.9600
O2—C31.206 (4)C5—H5A0.9600
C3—C21.470 (4)O1—C11.219 (4)
N1—C41.301 (4)O3—C11.340 (4)
N1—H1B0.8600O3—C61.445 (4)
N1—H1A0.8600C6—H6C0.9600
C2—C41.385 (5)C6—H6B0.9600
C2—C11.456 (5)C6—H6A0.9600
C4—H4A0.9300
C3—O4—C5115.6 (3)H5C—C5—H5B109.5
O2—C3—O4120.9 (3)O4—C5—H5A109.5
O2—C3—C2127.5 (3)H5C—C5—H5A109.5
O4—C3—C2111.6 (3)H5B—C5—H5A109.5
C4—N1—H1B120.0C1—O3—C6116.0 (3)
C4—N1—H1A120.0O1—C1—O3120.4 (3)
H1B—N1—H1A120.0O1—C1—C2123.1 (3)
C4—C2—C1118.3 (3)O3—C1—C2116.5 (3)
C4—C2—C3119.0 (3)O3—C6—H6C109.5
C1—C2—C3122.8 (3)O3—C6—H6B109.5
N1—C4—C2127.6 (3)H6C—C6—H6B109.5
N1—C4—H4A116.2O3—C6—H6A109.5
C2—C4—H4A116.2H6C—C6—H6A109.5
O4—C5—H5C109.5H6B—C6—H6A109.5
O4—C5—H5B109.5
C5—O4—C3—O20.8 (5)C3—C2—C4—N1178.6 (3)
C5—O4—C3—C2179.6 (3)C6—O3—C1—O10.1 (5)
O2—C3—C2—C4176.8 (3)C6—O3—C1—C2178.6 (3)
O4—C3—C2—C41.9 (4)C4—C2—C1—O10.8 (5)
O2—C3—C2—C12.5 (5)C3—C2—C1—O1180.0 (3)
O4—C3—C2—C1178.8 (3)C4—C2—C1—O3179.2 (3)
C1—C2—C4—N10.7 (6)C3—C2—C1—O31.5 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1B···O10.862.032.638 (2)128
N1—H1A···O2i0.862.022.848 (2)161
Symmetry code: (i) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC6H9NO4
Mr159.14
Crystal system, space groupMonoclinic, P21/c
Temperature (K)100
a, b, c (Å)9.3410 (19), 6.9000 (14), 11.725 (2)
β (°) 97.58 (3)
V3)749.1 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.12
Crystal size (mm)0.43 × 0.27 × 0.06
Data collection
DiffractometerOxford Diffraction GEMINI R
diffractometer
Absorption correctionAnalytical
(CrysAlis RED; Oxford Diffraction, 2006)
Tmin, Tmax0.892, 0.998
No. of measured, independent and
observed [I > 2σ(I)] reflections
14185, 1368, 841
Rint0.089
(sin θ/λ)max1)0.602
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.091, 0.261, 0.99
No. of reflections1368
No. of parameters102
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.62, 0.38

Computer programs: CrysAlis CCD (Oxford Diffraction, 2006), CrysAlis RED (Oxford Diffraction, 2006), SHELXS97 (Sheldrick, 2008), DIAMOND (Brandenburg, 1998), enCIFer (Allen et al., 2004).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1B···O10.862.0252.638 (2)127.5
N1—H1A···O2i0.862.0222.848 (2)160.8
Symmetry code: (i) x, y+1, z.
 

Acknowledgements

The authors thank the Grant Agency of the Slovak Republic, grant Nos. APVT-20–007304 and VEGA 1/0817/08, for support.

References

First citationAllen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335–338.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationBouzard, D. (1990). Recent Progress in the Chemical Synthesis of Antibiotics, p. 249. München: Springer-Verlag.  Google Scholar
First citationBrandenburg, K. (1998). DIAMOND. Crystal Impact GbR, Bonn, Germany.  Google Scholar
First citationChemla, D. & Zyss, J. (1987). Optical Properties of Organic Molecules and Crystals, Vol. 1, pp. 23–187. New York: Academic Press.  Google Scholar
First citationCook, A. G. (1969). Enamines: Syntheses, Structure and Reactions. New York: Marcel Dekker.  Google Scholar
First citationFreeman, F. (1981). LONZA Reaction of Malononitrile Derivatives, p. 925. Stuttgart: Georg Thieme Verlag.  Google Scholar
First citationNalwa, H. S., Watanabe, T. & Miyata, S. (1997). Nonlinear Optics of Organic Molecules and Polymers, pp. 87–329. Boca Ranton: CRC Press.  Google Scholar
First citationOxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, Oxfordshire, England.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationShmueli, U., Shanan-Atidi, H., Horwitz, H. & Shvo, Y. (1973). J. Chem. Soc. Perkin Trans. 2, pp. 657–662.  CSD CrossRef Google Scholar

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