2-Amino-2,3-dimethyl­butanamide

Yin, Y.

doi:10.1107/S1600536810015679

organic compounds

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ISSN: 2056-9890

Volume 66| Part 6| June 2010| Page o1258

https://doi.org/10.1107/S1600536810015679

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2-Amino-2,3-dimethylbutanamide

Yongbiao Yin ^a ^*

^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 ); Harir et al. (2007 ).

Experimental

Crystal data

C₆H₁₄N₂O
M_r = 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 ) T_min = 0.991, T_max = 0.993
3390 measured reflections
1503 independent reflections
922 reflections with I > 2σ(I)
R_int = 0.024

Refinement

R[F² > 2σ(F²)] = 0.049
wR(F²) = 0.152
S = 0.95
1503 reflections
86 parameters
H-atom parameters constrained
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; 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 ).

Supporting information

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S1600536810015679/jh2145sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810015679/jh2145Isup2.hkl

checkCIF report

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

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.

Structure description top

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

	Fig. 1. The molecular structure with atom labels and 30% probability displacement ellipsoids for non-H atoms.
	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

C₆H₁₄N₂O	F(000) = 288.0
M_r = 130.19	D_x = 1.128 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 3786 reflections
a = 12.1766 (8) Å	θ = 3.4–29.4°
b = 6.1741 (4) Å	µ = 0.08 mm⁻¹
c = 10.2322 (5) Å	T = 120 K
β = 94.682 (6)°	Prism, colourless
V = 766.69 (8) Å³	0.14 × 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 tube	922 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.024
φ and ω scans	θ_max = 26.0°, θ_min = 3.4°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −15→15
T_min = 0.991, T_max = 0.993	k = −7→6
3390 measured reflections	l = −8→12

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.049	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.152	H-atom parameters constrained
S = 0.95	w = 1/[σ²(F_o²) + (0.0943P)²] where P = (F_o² + 2F_c²)/3
1503 reflections	(Δ/σ)_max = 0.001
86 parameters	Δρ_max = 0.24 e Å⁻³
0 restraints	Δρ_min = −0.17 e Å⁻³

Crystal data top

C₆H₁₄N₂O	V = 766.69 (8) Å³
M_r = 130.19	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 12.1766 (8) Å	µ = 0.08 mm⁻¹
b = 6.1741 (4) Å	T = 120 K
c = 10.2322 (5) Å	0.14 × 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)
T_min = 0.991, T_max = 0.993	R_int = 0.024
3390 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.049	0 restraints
wR(F²) = 0.152	H-atom parameters constrained
S = 0.95	Δρ_max = 0.24 e Å⁻³
1503 reflections	Δρ_min = −0.17 e Å⁻³
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

	x	y	z	U_iso*/U_eq
N1	0.57193 (13)	0.1711 (3)	0.13703 (14)	0.0498 (5)
H1A	0.5245	0.0685	0.1239	0.060*
H1B	0.5902	0.2155	0.2155	0.060*
O1	0.59128 (12)	0.1981 (2)	−0.07665 (11)	0.0601 (5)
C1	0.61676 (14)	0.2604 (3)	0.03676 (16)	0.0387 (5)
C2	0.70199 (14)	0.4409 (3)	0.06667 (15)	0.0411 (5)
C3	0.81019 (15)	0.3346 (3)	0.12505 (19)	0.0550 (6)
H3	0.7932	0.2593	0.2053	0.066*
C4	0.89925 (19)	0.5008 (4)	0.1643 (3)	0.0846 (8)
H4A	0.9636	0.4281	0.2029	0.127*
H4B	0.8726	0.6000	0.2267	0.127*
H4C	0.9176	0.5791	0.0880	0.127*
C5	0.8548 (2)	0.1667 (4)	0.0355 (3)	0.0873 (9)
H5A	0.8749	0.2356	−0.0432	0.131*
H5B	0.7993	0.0593	0.0136	0.131*
H5C	0.9185	0.0988	0.0793	0.131*
C6	0.71901 (18)	0.5628 (3)	−0.05696 (19)	0.0570 (6)
H6A	0.6504	0.6252	−0.0912	0.086*
H6B	0.7454	0.4653	−0.1205	0.086*
H6C	0.7721	0.6757	−0.0382	0.086*
N2	0.66166 (17)	0.5932 (3)	0.16527 (19)	0.0751 (6)
H2B	0.6624	0.5270	0.2426	0.113*
H2C	0.5931	0.6334	0.1394	0.113*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0592 (10)	0.0583 (9)	0.0318 (8)	−0.0172 (8)	0.0032 (7)	0.0000 (7)
O1	0.0751 (10)	0.0746 (9)	0.0299 (7)	−0.0280 (7)	0.0000 (6)	−0.0034 (6)
C1	0.0427 (9)	0.0431 (9)	0.0297 (9)	−0.0011 (7)	−0.0004 (7)	0.0004 (7)
C2	0.0506 (10)	0.0412 (9)	0.0314 (9)	−0.0036 (8)	0.0022 (8)	−0.0013 (7)
C3	0.0506 (12)	0.0607 (12)	0.0521 (12)	−0.0076 (9)	−0.0044 (10)	0.0087 (10)
C4	0.0588 (13)	0.0998 (18)	0.0922 (18)	−0.0196 (13)	−0.0122 (13)	−0.0087 (15)
C5	0.0627 (14)	0.0735 (15)	0.124 (2)	0.0132 (12)	−0.0037 (15)	−0.0172 (15)
C6	0.0761 (13)	0.0509 (11)	0.0432 (11)	−0.0189 (10)	−0.0011 (10)	0.0130 (9)
N2	0.0845 (14)	0.0712 (12)	0.0707 (12)	0.0004 (10)	0.0127 (11)	−0.0231 (10)

Geometric parameters (Å, º) top

N1—C1	1.321 (2)	C4—H4A	0.9600
N1—H1A	0.8600	C4—H4B	0.9600
N1—H1B	0.8600	C4—H4C	0.9600
O1—C1	1.2377 (18)	C5—H5A	0.9600
C1—C2	1.536 (2)	C5—H5B	0.9600
C2—N2	1.492 (2)	C5—H5C	0.9600
C2—C6	1.501 (2)	C6—H6A	0.9600
C2—C3	1.548 (2)	C6—H6B	0.9600
C3—C5	1.513 (3)	C6—H6C	0.9600
C3—C4	1.523 (3)	N2—H2B	0.8900
C3—H3	0.9800	N2—H2C	0.8900

C1—N1—H1A	120.0	H4A—C4—H4B	109.5
C1—N1—H1B	120.0	C3—C4—H4C	109.5
H1A—N1—H1B	120.0	H4A—C4—H4C	109.5
O1—C1—N1	120.70 (16)	H4B—C4—H4C	109.5
O1—C1—C2	121.70 (15)	C3—C5—H5A	109.5
N1—C1—C2	117.59 (13)	C3—C5—H5B	109.5
N2—C2—C6	109.24 (16)	H5A—C5—H5B	109.5
N2—C2—C1	109.75 (15)	C3—C5—H5C	109.5
C6—C2—C1	109.47 (13)	H5A—C5—H5C	109.5
N2—C2—C3	108.86 (13)	H5B—C5—H5C	109.5
C6—C2—C3	111.48 (16)	C2—C6—H6A	109.5
C1—C2—C3	108.02 (14)	C2—C6—H6B	109.5
C5—C3—C4	109.74 (19)	H6A—C6—H6B	109.5
C5—C3—C2	113.15 (15)	C2—C6—H6C	109.5
C4—C3—C2	112.42 (17)	H6A—C6—H6C	109.5
C5—C3—H3	107.1	H6B—C6—H6C	109.5
C4—C3—H3	107.1	C2—N2—H2B	109.4
C2—C3—H3	107.1	C2—N2—H2C	109.1
C3—C4—H4A	109.5	H2B—N2—H2C	109.5
C3—C4—H4B	109.5

O1—C1—C2—N2	136.55 (18)	N2—C2—C3—C5	176.71 (19)
N1—C1—C2—N2	−44.2 (2)	C6—C2—C3—C5	−62.7 (2)
O1—C1—C2—C6	16.7 (2)	C1—C2—C3—C5	57.6 (2)
N1—C1—C2—C6	−164.08 (17)	N2—C2—C3—C4	−58.3 (2)
O1—C1—C2—C3	−104.90 (19)	C6—C2—C3—C4	62.3 (2)
N1—C1—C2—C3	74.3 (2)	C1—C2—C3—C4	−177.40 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	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+1/2, z+1/2; (ii) −x+1, −y, −z; (iii) −x+1, −y+1, −z.

Experimental details

Crystal data
Chemical formula	C₆H₁₄N₂O
M_r	130.19
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	120
a, b, c (Å)	12.1766 (8), 6.1741 (4), 10.2322 (5)
β (°)	94.682 (6)
V (Å³)	766.69 (8)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.14 × 0.11 × 0.10

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.991, 0.993
No. of measured, independent and observed [I > 2σ(I)] reflections	3390, 1503, 922
R_int	0.024
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.049, 0.152, 0.95
No. of reflections	1503
No. of parameters	86
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	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···A	D—H	H···A	D···A	D—H···A
N2—H2B···O1ⁱ	0.89	2.52	3.364 (2)	157.8
N1—H1B···O1ⁱ	0.86	2.19	3.0295 (19)	164.6
N1—H1A···O1ⁱⁱ	0.86	2.20	3.054 (2)	175.8
N2—H2C···O1ⁱⁱⁱ	0.89	2.51	3.393 (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

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