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

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ISSN: 2056-9890

2-Amino-2,3-di­methyl­butanamide

aDepartment of Chemistry, Mudanjiang Teachers College, Mudanjiang 157012, People's Republic of China
*Correspondence e-mail: yinyongbiao68@163.com

(Received 16 April 2010; accepted 28 April 2010; online 8 May 2010)

The title compound, C6H14N2O, was synthesized by the reaction between 2-amino-2,3-dimethyl­butanonitrile and oil of vitriol (sulfuric acid). A racemic mixture of L- and R-2-amino-2,3-di­methyl­butanamide was characterized crystallographically. In the crystal structure, inter­molecular N—H⋯O hydrogen bonds link the two enanti­omers into a three-dimensional network.

Related literature

2-Amino-2,3-dimethyl­butanamide, a common inter­mediate in the synthesis of imidazolinone compounds, is an excellent weedicide, usually used as racemic mixture of the levo and dextral enanti­omers, see: Goatz et al. (1990[Goatz, A., Lavy, T. & Gbur, E. (1990). Weed Sci. 38, 421-489.]); Harir et al. (2007[Harir, M., Gaspar, A., Frommberger, M., Lucio, M., Azzouzi, M. E., Martens, D., Kettrup, A. & Schmitt-Kopplin, P. (2007). J. Agric. Food Chem. 55, 9936-9943.]).

[Scheme 1]

Experimental

Crystal data
  • C6H14N2O

  • Mr = 130.19

  • Monoclinic, P 21 /c

  • a = 12.1766 (8) Å

  • b = 6.1741 (4) Å

  • c = 10.2322 (5) Å

  • β = 94.682 (6)°

  • V = 766.69 (8) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.08 mm−1

  • T = 120 K

  • 0.14 × 0.11 × 0.10 mm

Data collection
  • Bruker SMART APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker, (2005). APEX2, SAINT and SADABS. Bruker AXS, Inc., Madison, Wisconsin, USA.]) Tmin = 0.991, Tmax = 0.993

  • 3390 measured reflections

  • 1503 independent reflections

  • 922 reflections with I > 2σ(I)

  • Rint = 0.024

Refinement
  • R[F2 > 2σ(F2)] = 0.049

  • wR(F2) = 0.152

  • S = 0.95

  • 1503 reflections

  • 86 parameters

  • H-atom parameters constrained

  • Δρmax = 0.24 e Å−3

  • Δρmin = −0.17 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H2B⋯O1i 0.89 2.52 3.364 (2) 158
N1—H1B⋯O1i 0.86 2.19 3.0295 (19) 165
N1—H1A⋯O1ii 0.86 2.20 3.054 (2) 176
N2—H2C⋯O1iii 0.89 2.51 3.393 (3) 172
Symmetry codes: (i) [x, -y+{\script{1\over 2}}, z+{\script{1\over 2}}]; (ii) -x+1, -y, -z; (iii) -x+1, -y+1, -z.

Data collection: APEX2 (Bruker, 2005[Bruker, (2005). APEX2, SAINT and SADABS. Bruker AXS, Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker, (2005). APEX2, SAINT and SADABS. Bruker AXS, Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997[Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.]); software used to prepare material for publication: WinGX (Farrugia, 1999[Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837-838.]).

Supporting information


Comment top

2-Amino-2,3-dimethylbutanamide is common intermediate in the synthesis of imidazolinone compounds, excellent weedicide, usually used as racemic mixture of the levo and dextral enantiomers (Goatz, et al., 1990; Harir, et al., 2007). We report herein the synthesis and the structural determination of the title molecule. The as synthesis compound contains the both chiral components of L- and R-2-amino-2,3-dimethylbutanamide, and as a consequence, the space group of crystal is centrosymmetric P21/c which contain gliding plane and center of symmetry. In addition, intermolecular N–H···O hydrogen bonds linked the two enantiomers into unlimited three dimensional network.

Related literature top

2-Amino-2,3-dimethylbutanamide, a common intermediate in the synthesis of imidazolinone compounds, is an excellent weedicide, usually used as racemic mixture of the levo and dextral enantiomers, see: Goatz et al. (1990); Harir et al. (2007).

Experimental top

2-Amino-2,3-dimethylbutanenitrile liquid (46.7 g, 0.417 mol) was added to the oil of vitriol solution (104.2 ml) under N2 protection in cold water bath. Next, the solution along with the white solid appeared was slowly poured into 150 grams of ice water after three days of stir at room temperature. Then, Na2CO3 (221 g) and 50% NaOH (38 ml) were consumed to basify the solution to pH value 9.0, giving rise to plenty of white solid. The title compound (25.8 g) with a m.p of 76-80 degrees, yielding 47.6% was obtained after filtration and purification through extraction with dichloromethane. The suitable single crystals for X-ray diffraction was from slow evaporation of solvent from the title compound dichloromethane solution.

Refinement top

H atoms bonded to O atom of free water molecule were located in a difference map. All the other H atoms were placed in calculated positions and refined as riding, with C–H = 0.96–0.98 Å, and O–H = 0.85 Å, and Uiso(H) = 1.2 or 1.5Ueq(C,O).

Structure description top

2-Amino-2,3-dimethylbutanamide is common intermediate in the synthesis of imidazolinone compounds, excellent weedicide, usually used as racemic mixture of the levo and dextral enantiomers (Goatz, et al., 1990; Harir, et al., 2007). We report herein the synthesis and the structural determination of the title molecule. The as synthesis compound contains the both chiral components of L- and R-2-amino-2,3-dimethylbutanamide, and as a consequence, the space group of crystal is centrosymmetric P21/c which contain gliding plane and center of symmetry. In addition, intermolecular N–H···O hydrogen bonds linked the two enantiomers into unlimited three dimensional network.

2-Amino-2,3-dimethylbutanamide, a common intermediate in the synthesis of imidazolinone compounds, is an excellent weedicide, usually used as racemic mixture of the levo and dextral enantiomers, see: Goatz et al. (1990); Harir et al. (2007).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top
[Figure 1] Fig. 1. The molecular structure with atom labels and 30% probability displacement ellipsoids for non-H atoms.
[Figure 2] Fig. 2. The packing diagram of molecules, viewed down the b axis, with the weak interactions shown as dashed lines.
2-Amino-2,3-dimethylbutanamide top
Crystal data top
C6H14N2OF(000) = 288.0
Mr = 130.19Dx = 1.128 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 3786 reflections
a = 12.1766 (8) Åθ = 3.4–29.4°
b = 6.1741 (4) ŵ = 0.08 mm1
c = 10.2322 (5) ÅT = 120 K
β = 94.682 (6)°Prism, colourless
V = 766.69 (8) Å30.14 × 0.11 × 0.10 mm
Z = 4
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
1503 independent reflections
Radiation source: fine-focus sealed tube922 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.024
φ and ω scansθmax = 26.0°, θmin = 3.4°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 1515
Tmin = 0.991, Tmax = 0.993k = 76
3390 measured reflectionsl = 812
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)] = 0.049Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.152H-atom parameters constrained
S = 0.95 w = 1/[σ2(Fo2) + (0.0943P)2]
where P = (Fo2 + 2Fc2)/3
1503 reflections(Δ/σ)max = 0.001
86 parametersΔρmax = 0.24 e Å3
0 restraintsΔρmin = 0.17 e Å3
Crystal data top
C6H14N2OV = 766.69 (8) Å3
Mr = 130.19Z = 4
Monoclinic, P21/cMo Kα radiation
a = 12.1766 (8) ŵ = 0.08 mm1
b = 6.1741 (4) ÅT = 120 K
c = 10.2322 (5) Å0.14 × 0.11 × 0.10 mm
β = 94.682 (6)°
Data collection top
Bruker SMART APEXII CCD area-detector
diffractometer
1503 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
922 reflections with I > 2σ(I)
Tmin = 0.991, Tmax = 0.993Rint = 0.024
3390 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0490 restraints
wR(F2) = 0.152H-atom parameters constrained
S = 0.95Δρmax = 0.24 e Å3
1503 reflectionsΔρmin = 0.17 e Å3
86 parameters
Special details top

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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
N10.57193 (13)0.1711 (3)0.13703 (14)0.0498 (5)
H1A0.52450.06850.12390.060*
H1B0.59020.21550.21550.060*
O10.59128 (12)0.1981 (2)0.07665 (11)0.0601 (5)
C10.61676 (14)0.2604 (3)0.03676 (16)0.0387 (5)
C20.70199 (14)0.4409 (3)0.06667 (15)0.0411 (5)
C30.81019 (15)0.3346 (3)0.12505 (19)0.0550 (6)
H30.79320.25930.20530.066*
C40.89925 (19)0.5008 (4)0.1643 (3)0.0846 (8)
H4A0.96360.42810.20290.127*
H4B0.87260.60000.22670.127*
H4C0.91760.57910.08800.127*
C50.8548 (2)0.1667 (4)0.0355 (3)0.0873 (9)
H5A0.87490.23560.04320.131*
H5B0.79930.05930.01360.131*
H5C0.91850.09880.07930.131*
C60.71901 (18)0.5628 (3)0.05696 (19)0.0570 (6)
H6A0.65040.62520.09120.086*
H6B0.74540.46530.12050.086*
H6C0.77210.67570.03820.086*
N20.66166 (17)0.5932 (3)0.16527 (19)0.0751 (6)
H2B0.66240.52700.24260.113*
H2C0.59310.63340.13940.113*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
N10.0592 (10)0.0583 (9)0.0318 (8)0.0172 (8)0.0032 (7)0.0000 (7)
O10.0751 (10)0.0746 (9)0.0299 (7)0.0280 (7)0.0000 (6)0.0034 (6)
C10.0427 (9)0.0431 (9)0.0297 (9)0.0011 (7)0.0004 (7)0.0004 (7)
C20.0506 (10)0.0412 (9)0.0314 (9)0.0036 (8)0.0022 (8)0.0013 (7)
C30.0506 (12)0.0607 (12)0.0521 (12)0.0076 (9)0.0044 (10)0.0087 (10)
C40.0588 (13)0.0998 (18)0.0922 (18)0.0196 (13)0.0122 (13)0.0087 (15)
C50.0627 (14)0.0735 (15)0.124 (2)0.0132 (12)0.0037 (15)0.0172 (15)
C60.0761 (13)0.0509 (11)0.0432 (11)0.0189 (10)0.0011 (10)0.0130 (9)
N20.0845 (14)0.0712 (12)0.0707 (12)0.0004 (10)0.0127 (11)0.0231 (10)
Geometric parameters (Å, º) top
N1—C11.321 (2)C4—H4A0.9600
N1—H1A0.8600C4—H4B0.9600
N1—H1B0.8600C4—H4C0.9600
O1—C11.2377 (18)C5—H5A0.9600
C1—C21.536 (2)C5—H5B0.9600
C2—N21.492 (2)C5—H5C0.9600
C2—C61.501 (2)C6—H6A0.9600
C2—C31.548 (2)C6—H6B0.9600
C3—C51.513 (3)C6—H6C0.9600
C3—C41.523 (3)N2—H2B0.8900
C3—H30.9800N2—H2C0.8900
C1—N1—H1A120.0H4A—C4—H4B109.5
C1—N1—H1B120.0C3—C4—H4C109.5
H1A—N1—H1B120.0H4A—C4—H4C109.5
O1—C1—N1120.70 (16)H4B—C4—H4C109.5
O1—C1—C2121.70 (15)C3—C5—H5A109.5
N1—C1—C2117.59 (13)C3—C5—H5B109.5
N2—C2—C6109.24 (16)H5A—C5—H5B109.5
N2—C2—C1109.75 (15)C3—C5—H5C109.5
C6—C2—C1109.47 (13)H5A—C5—H5C109.5
N2—C2—C3108.86 (13)H5B—C5—H5C109.5
C6—C2—C3111.48 (16)C2—C6—H6A109.5
C1—C2—C3108.02 (14)C2—C6—H6B109.5
C5—C3—C4109.74 (19)H6A—C6—H6B109.5
C5—C3—C2113.15 (15)C2—C6—H6C109.5
C4—C3—C2112.42 (17)H6A—C6—H6C109.5
C5—C3—H3107.1H6B—C6—H6C109.5
C4—C3—H3107.1C2—N2—H2B109.4
C2—C3—H3107.1C2—N2—H2C109.1
C3—C4—H4A109.5H2B—N2—H2C109.5
C3—C4—H4B109.5
O1—C1—C2—N2136.55 (18)N2—C2—C3—C5176.71 (19)
N1—C1—C2—N244.2 (2)C6—C2—C3—C562.7 (2)
O1—C1—C2—C616.7 (2)C1—C2—C3—C557.6 (2)
N1—C1—C2—C6164.08 (17)N2—C2—C3—C458.3 (2)
O1—C1—C2—C3104.90 (19)C6—C2—C3—C462.3 (2)
N1—C1—C2—C374.3 (2)C1—C2—C3—C4177.40 (17)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2B···O1i0.892.523.364 (2)158
N1—H1B···O1i0.862.193.0295 (19)165
N1—H1A···O1ii0.862.203.054 (2)176
N2—H2C···O1iii0.892.513.393 (3)172
Symmetry codes: (i) x, y+1/2, z+1/2; (ii) x+1, y, z; (iii) x+1, y+1, z.

Experimental details

Crystal data
Chemical formulaC6H14N2O
Mr130.19
Crystal system, space groupMonoclinic, P21/c
Temperature (K)120
a, b, c (Å)12.1766 (8), 6.1741 (4), 10.2322 (5)
β (°) 94.682 (6)
V3)766.69 (8)
Z4
Radiation typeMo Kα
µ (mm1)0.08
Crystal size (mm)0.14 × 0.11 × 0.10
Data collection
DiffractometerBruker SMART APEXII CCD area-detector
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.991, 0.993
No. of measured, independent and
observed [I > 2σ(I)] reflections
3390, 1503, 922
Rint0.024
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.049, 0.152, 0.95
No. of reflections1503
No. of parameters86
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.24, 0.17

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2B···O1i0.892.523.364 (2)157.8
N1—H1B···O1i0.862.193.0295 (19)164.6
N1—H1A···O1ii0.862.203.054 (2)175.8
N2—H2C···O1iii0.892.513.393 (3)171.5
Symmetry codes: (i) x, y+1/2, z+1/2; (ii) x+1, y, z; (iii) x+1, y+1, z.
 

Acknowledgements

The author thanks the Natural Science Foundation of Heilongjiang Province for financial support.

References

First citationBruker, (2005). APEX2, SAINT and SADABS. Bruker AXS, Inc., Madison, Wisconsin, USA.  Google Scholar
First citationFarrugia, L. J. (1997). J. Appl. Cryst. 30, 565.  CrossRef IUCr Journals Google Scholar
First citationFarrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838.  CrossRef CAS IUCr Journals Google Scholar
First citationGoatz, A., Lavy, T. & Gbur, E. (1990). Weed Sci. 38, 421–489.  Google Scholar
First citationHarir, M., Gaspar, A., Frommberger, M., Lucio, M., Azzouzi, M. E., Martens, D., Kettrup, A. & Schmitt-Kopplin, P. (2007). J. Agric. Food Chem. 55, 9936–9943.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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