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

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ISSN: 2056-9890

N,N′-Dimeth­­oxy-N,N′-di­methyl­succinamide

aMedical College of Henan University, Henan University, Kaifeng 475004, People's Republic of China
*Correspondence e-mail: ysum@yahoo.cn

(Received 16 June 2008; accepted 17 June 2008; online 21 June 2008)

The title compound, C8H16N2O4, is a Weinreb amide that is also an important inter­mediate for the preparation of ketones and aldehydes. The molecule possesses a centre of symmetry.

Related literature

For related literature, see: Nahm & Weinreb (1981[Nahm, S. & Weinreb, S. M. (1981). Tetrahedron Lett. 22, 3815-3818.]).

[Scheme 1]

Experimental

Crystal data
  • C8H16N2O4

  • Mr = 204.23

  • Monoclinic, P 21 /c

  • a = 4.2645 (15) Å

  • b = 11.152 (4) Å

  • c = 11.165 (4) Å

  • β = 98.485 (5)°

  • V = 525.2 (3) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 296 (2) K

  • 0.20 × 0.16 × 0.13 mm

Data collection
  • Bruker SMART APEX CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 2001[Sheldrick, G. M. (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.980, Tmax = 0.987

  • 2116 measured reflections

  • 909 independent reflections

  • 776 reflections with I > 2σ(I)

  • Rint = 0.015

Refinement
  • R[F2 > 2σ(F2)] = 0.055

  • wR(F2) = 0.174

  • S = 1.01

  • 909 reflections

  • 64 parameters

  • H-atom parameters constrained

  • Δρmax = 0.25 e Å−3

  • Δρmin = −0.24 e Å−3

Data collection: SMART (Bruker, 2001[Bruker (2001). SAINT-Plus and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SMART; data reduction: SAINT-Plus (Bruker, 2001[Bruker (2001). SAINT-Plus and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); 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: PLATON (Spek, 2003[Spek, A. L. (2003). J. Appl. Cryst. 36, 7-13.]); software used to prepare material for publication: PLATON.

Supporting information


Comment top

The Weinreb amides are widely recognized as effective acylating agents since they react with organometallics (RM, M = MgBr, Li) to produce ketones without side products in organic synthesis, including the total synthesis of complex natural products (Nahm & Weinreb, 1981). We here reported the structure of the Weinreb amides related title compound, (I).

Compound (I), is the synthetic intermediate, whose molecule is the centrosymmetric structure (Fig.1). In the symmetric unit, the C1—O1 bond distance is 1.224 (2) Å, which displays a typical double-bond of ketone carbonyl. Whereas, the N1—C1 bond distance of 1.342 (2) Å is obviously shorter than N1—C4 of 1.445 (2) Å, indicates that amide bond N1—C1 has some proporties of double-bond.

Related literature top

For related literature, see: Nahm & Weinreb (1981).

Experimental top

Triethylamine (25 ml, 180 mmol) was added slowly by cannulation to a stirred suspension of N,O-dimethylhydroxylamine (9.0 g, 92.25 mmol) and succinyl chloride (100 ml) in dichloromethane at 273 K under N2. After stirring for 2 h the solution was allowed to warm to room temperature and quenched with saturated aqueous sodium bicarbonate solution (50 ml). The layers were separated and the aqueous layer was extracted with dichloromethane (2×25 ml). The combined organic extracts were washed with brine (18.5 ml), dried (MgSO4) and evaporated under reduced pressure to give the compound (I) (7.365 g, 83%) as light brown needles. The molecule formula, C8H16N2O4 was established by EIMS m/z:144(M+ –N(CH3)OCH3). Spectroscopic analysis, 1H NMR (400 MHz; CDCl3-d6) δ:3.75 (6H, s, OCH3), 3.19 (6H, s, NCH3) and 2.78 (4H, s, CH2); 13C NMR (400 MHz; CDCl3-d6) δ:173.8 (C=O), 61.6 (OCH3), 32.6 and 26.8.

Refinement top

H atoms were treated as riding, with C—H distances in the range of 0.96–0.97 Å, and were refined as riding with Uiso(H) =1.2Ueq(Cmethylene) and Uiso(H)=1.5Ueq(Cmethyl).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SMART (Bruker, 2001); data reduction: SAINT-Plus (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLATON (Spek, 2003); software used to prepare material for publication: PLATON (Spek, 2003).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.
N,N'-Dimethoxy-N,N'-dimethylsuccinamide top
Crystal data top
C8H16N2O4F(000) = 220
Mr = 204.23Dx = 1.291 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 925 reflections
a = 4.2645 (15) Åθ = 2.6–26.6°
b = 11.152 (4) ŵ = 0.10 mm1
c = 11.165 (4) ÅT = 296 K
β = 98.485 (5)°Block, yellow
V = 525.2 (3) Å30.20 × 0.16 × 0.13 mm
Z = 2
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
909 independent reflections
Radiation source: fine-focus sealed tube776 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.015
ϕ and ω scansθmax = 25.0°, θmin = 2.6°
Absorption correction: multi-scan
(SADABS; Sheldrick, 2001)
h = 55
Tmin = 0.980, Tmax = 0.987k = 913
2116 measured reflectionsl = 1311
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)] = 0.055Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.174H-atom parameters constrained
S = 1.01 w = 1/[σ2(Fo2) + (0.117P)2 + 0.1547P]
where P = (Fo2 + 2Fc2)/3
909 reflections(Δ/σ)max < 0.001
64 parametersΔρmax = 0.25 e Å3
0 restraintsΔρmin = 0.24 e Å3
Crystal data top
C8H16N2O4V = 525.2 (3) Å3
Mr = 204.23Z = 2
Monoclinic, P21/cMo Kα radiation
a = 4.2645 (15) ŵ = 0.10 mm1
b = 11.152 (4) ÅT = 296 K
c = 11.165 (4) Å0.20 × 0.16 × 0.13 mm
β = 98.485 (5)°
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
909 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2001)
776 reflections with I > 2σ(I)
Tmin = 0.980, Tmax = 0.987Rint = 0.015
2116 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0550 restraints
wR(F2) = 0.174H-atom parameters constrained
S = 1.01Δρmax = 0.25 e Å3
909 reflectionsΔρmin = 0.24 e Å3
64 parameters
Special details top

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
O10.2198 (3)0.51856 (11)0.21773 (11)0.0633 (4)
O20.4066 (3)0.76550 (10)0.05213 (10)0.0498 (3)
N10.3748 (4)0.69395 (13)0.15260 (12)0.0525 (4)
C10.2269 (4)0.58794 (14)0.13325 (15)0.0434 (4)
C20.0721 (4)0.56191 (14)0.00580 (15)0.0452 (4)
H2A0.22890.56890.04850.054*
H2B0.09200.62100.01830.054*
C30.2116 (5)0.87038 (16)0.0512 (2)0.0643 (6)
H3A0.23510.91860.01810.096*
H3B0.27540.91590.12370.096*
H3C0.00610.84680.04750.096*
C40.5720 (5)0.72712 (18)0.26424 (17)0.0616 (5)
H4A0.53470.67280.32740.092*
H4B0.52140.80730.28610.092*
H4C0.79100.72320.25350.092*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0974 (10)0.0429 (6)0.0457 (7)0.0074 (6)0.0023 (6)0.0066 (5)
O20.0637 (7)0.0412 (6)0.0458 (7)0.0059 (5)0.0127 (5)0.0014 (5)
N10.0754 (9)0.0421 (7)0.0376 (8)0.0108 (7)0.0004 (7)0.0014 (6)
C10.0550 (9)0.0329 (7)0.0413 (9)0.0029 (6)0.0035 (7)0.0003 (7)
C20.0568 (9)0.0341 (8)0.0425 (9)0.0008 (7)0.0003 (7)0.0004 (7)
C30.0740 (12)0.0423 (10)0.0760 (13)0.0006 (8)0.0094 (10)0.0030 (9)
C40.0767 (12)0.0605 (11)0.0445 (10)0.0137 (9)0.0015 (9)0.0093 (9)
Geometric parameters (Å, º) top
O1—C11.2238 (19)C2—H2B0.9700
O2—N11.3994 (18)C3—H3A0.9600
O2—C31.434 (2)C3—H3B0.9600
N1—C11.342 (2)C3—H3C0.9600
N1—C41.445 (2)C4—H4A0.9600
C1—C21.506 (2)C4—H4B0.9600
C2—C2i1.510 (3)C4—H4C0.9600
C2—H2A0.9700
N1—O2—C3110.25 (13)O2—C3—H3A109.5
C1—N1—O2118.16 (13)O2—C3—H3B109.5
C1—N1—C4124.34 (15)H3A—C3—H3B109.5
O2—N1—C4115.63 (14)O2—C3—H3C109.5
O1—C1—N1119.82 (15)H3A—C3—H3C109.5
O1—C1—C2123.31 (15)H3B—C3—H3C109.5
N1—C1—C2116.87 (14)N1—C4—H4A109.5
C1—C2—C2i111.95 (17)N1—C4—H4B109.5
C1—C2—H2A109.2H4A—C4—H4B109.5
C2i—C2—H2A109.2N1—C4—H4C109.5
C1—C2—H2B109.2H4A—C4—H4C109.5
C2i—C2—H2B109.2H4B—C4—H4C109.5
H2A—C2—H2B107.9
C3—O2—N1—C1110.95 (17)O2—N1—C1—C27.3 (2)
C3—O2—N1—C483.94 (19)C4—N1—C1—C2171.05 (17)
O2—N1—C1—O1173.52 (15)O1—C1—C2—C2i3.6 (3)
C4—N1—C1—O19.8 (3)N1—C1—C2—C2i177.24 (18)
Symmetry code: (i) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC8H16N2O4
Mr204.23
Crystal system, space groupMonoclinic, P21/c
Temperature (K)296
a, b, c (Å)4.2645 (15), 11.152 (4), 11.165 (4)
β (°) 98.485 (5)
V3)525.2 (3)
Z2
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.20 × 0.16 × 0.13
Data collection
DiffractometerBruker SMART APEX CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 2001)
Tmin, Tmax0.980, 0.987
No. of measured, independent and
observed [I > 2σ(I)] reflections
2116, 909, 776
Rint0.015
(sin θ/λ)max1)0.595
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.055, 0.174, 1.01
No. of reflections909
No. of parameters64
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.25, 0.24

Computer programs: SMART (Bruker, 2001), SAINT-Plus (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2003).

 

References

First citationBruker (2001). SAINT-Plus and SMART. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationNahm, S. & Weinreb, S. M. (1981). Tetrahedron Lett. 22, 3815–3818.  CrossRef CAS Web of Science Google Scholar
First citationSheldrick, G. M. (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSpek, A. L. (2003). J. Appl. Cryst. 36, 7–13.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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Journal logoCRYSTALLOGRAPHIC
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ISSN: 2056-9890
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