2,5-Dioxopyrrolidin-1-yl 2-methyl­prop-2-enoate

Abstract

In the title compound, C₈H₉NO₄, the pyrrolidine ring (r.m.s. deviation 0.014 Å) is almost normal to the mean plane of the propenoate group (r.m.s deviation 0.028 Å), making a dihedral angle of 86.58 (4)°. In the crystal, mol­ecules are linked via pairs of weak C—H⋯O hydrogen bonds, forming inversion dimers which stack along the c axis.

Related literature  

For synthetic procedures, see: Batz et al. (1972 ▶); Rathfon & Tew (2008 ▶). For free radical polymerization and controlled free radical (ATRP) polymerizations to form homo- and copolymers, see: Batz et al. (1972 ▶); Rathfon & Tew (2008 ▶). For a background on post-polymerization modification to create functional polymers, see: Gauthier et al. (2009 ▶). For a review of topochemical polymerization in crystals, see: Matsumoto (2003 ▶). For a disscussion addressing the conformation of methyl substituents on alkenes, see: Deslongchamps & Deslongchamps (2011 ▶).

Experimental  

Crystal data  

• C₈H₉NO₄

• M _r = 183.16

• Monoclinic,

• a = 9.6137 (8) Å

• b = 10.9317 (9) Å

• c = 8.4911 (7) Å

• β = 102.522 (2)°

• V = 871.14 (12) ų

• Z = 4

• Mo Kα radiation

• μ = 0.11 mm⁻¹

• T = 173 K

• 0.24 × 0.14 × 0.07 mm

Data collection  

• Bruker Kappa APEXII DUO diffractometer

• Absorption correction: multi-scan (SADABS; Sheldrick, 2004 ▶) T _min = 0.884, T _max = 1.000

• 20817 measured reflections

• 1595 independent reflections

• 1353 reflections with I > 2σ(I)

• R _int = 0.042

Refinement  

• R[F ² > 2σ(F ²)] = 0.036

• wR(F ²) = 0.085

• S = 1.06

• 1595 reflections

• 119 parameters

• H-atom parameters constrained

• Δρ_max = 0.19 e Å⁻³

• Δρ_min = −0.17 e Å⁻³

Data collection: APEX2 (Bruker, 2013 ▶); cell refinement: SAINT (Bruker, 2013 ▶); 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, 2012 ▶); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008 ▶).

Supplementary Material

CCDC reference: 990423

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C7—H7A⋯O2i	0.98	2.54	3.393 (2)	145

Symmetry code: (i) .

supplementary crystallographic information

1. Comment

The title compound is a monomer for free radical polymerization (Batz et al., 1972) and controlled free radical (ATRP) polymerizations (Rathfon & Tew, 2008) to form homo- and copolymers. After preliminary polymerization, these polymers serve as candidates to undergo post-polymerization modification to create functional polymers (Gauthier et al., 2009). A structure determination was undertaken to investigate the possibility of free radical, topochemical polymerization of this monomer while being exposed to X-ray radiation (Matsumoto, 2003). The molecular unit is shown in Figure 1. The crystal structure reveals that no polymerization has taken place. The asymmetric unit consists of a single monomer unit packed into a monoclinic cell with a volume of 871 ų. While analysis of the intermolecular contacts within the unit cell reveals a close contact of 3.487 Å between the carbons of adjacent double bonds (C6 and C8), this contact occurs between a pair of adjacent molecules but is not maintained with additional molecules in order to achieve a favorable pathway for polymerization. Figure 2 shows the packing in the unit cell. The molecule is composed of two planar regions. Least-squares planar analysis reveals r.m.s. deviation from planarity for the pyrrolidine ring of 0.014 Å and 0.028 Å for the propenoate portion. The two planes are essentially normal to each other with an angle of 86.58 (4) degrees between least-squares planes. The conformation of the methyl H atoms is found to be syn to the vinylic proton. This is the preferred configuration by approximately 2 kcal/mol (Deslongchamps & Deslongchamps, 2011).

2. Experimental

Crystals of the title compound, C₈H₉NO₄, were grown unintentionally from slow evaporation of a solution of the compound in 1:4 ethyl acetate:hexanes at 0 °C.

3. Refinement

Although all of the H-atoms were located in difference maps, H-atoms were placed at idealized positions and refined with a riding model having U_iso(H) = 1.2 times U_eq(C).

Figures

Fig. 1.

The molecular structure of the title compound, with atom labels and 50% probability displacement ellipsoids for non-H atoms

Fig. 2.

Unit cell view along the +a axis showing the lack of proper stacking for polymerization to occur.

Crystal data

C8H9NO4	F(000) = 384
Mr = 183.16	Dx = 1.397 Mg m−3Dm = 1.337 (2) Mg m−3Dm measured by flotation
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 9.6137 (8) Å	Cell parameters from 8309 reflections
b = 10.9317 (9) Å	θ = 2.2–25.3°
c = 8.4911 (7) Å	µ = 0.11 mm−1
β = 102.522 (2)°	T = 173 K
V = 871.14 (12) Å3	Parallelpiped, colourless
Z = 4	0.24 × 0.14 × 0.07 mm

Data collection

Bruker Kappa APEXII DUO diffractometer	1595 independent reflections
Radiation source: a micro-focus source with X-ray optics for beam focussing and collimation	1353 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.042
Detector resolution: 512 pixels mm-1	θmax = 25.3°, θmin = 2.2°
combination of ω and phi scans	h = −11→11
Absorption correction: multi-scan (SADABS; Sheldrick, 2004)	k = −13→13
Tmin = 0.884, Tmax = 1.000	l = −10→10
20817 measured reflections

Refinement

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)] = 0.036	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.085	H-atom parameters constrained
S = 1.06	w = 1/[σ2(Fo2) + (0.0278P)2 + 0.472P] where P = (Fo2 + 2Fc2)/3
1595 reflections	(Δ/σ)max < 0.001
119 parameters	Δρmax = 0.19 e Å−3
0 restraints	Δρmin = −0.17 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.CheckCIF detected one Alert level C stating that a large K value of 2.279 was detected in the Analysis of Variance. Examination of the SHELX output does reveal one large K value (1.967) for the Fc/Fc(max of 0.000). Examination of the K values as a function of resolution shows no large K values from inf to 0.83 Å. Our conclusion is that the large K value results from very weak relections in the 0.80 - 0.60 A region and should have a neglibile effect upon the final structural results while the inclusion of the data would minimize termination effects in the calculation of electron density.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
C1	0.82074 (17)	0.05447 (15)	0.09507 (19)	0.0323 (4)
H1A	0.8376	0.0287	−0.0110	0.039*
H1B	0.7895	−0.0176	0.1490	0.039*
C2	0.95609 (18)	0.10915 (15)	0.19895 (19)	0.0326 (4)
H2A	0.9894	0.0594	0.2973	0.039*
H2B	1.0329	0.1126	0.1380	0.039*
C3	0.91646 (17)	0.23566 (15)	0.24251 (18)	0.0301 (4)
C4	0.71008 (17)	0.15357 (14)	0.07441 (18)	0.0283 (4)
C5	0.72829 (16)	0.44523 (14)	0.06764 (17)	0.0261 (3)
C6	0.66346 (16)	0.56484 (14)	0.09024 (18)	0.0270 (4)
C7	0.6865 (2)	0.66054 (16)	−0.0276 (2)	0.0420 (4)
H7A	0.6435	0.7377	−0.0037	0.063*
H7B	0.6422	0.6342	−0.1373	0.063*
H7C	0.7890	0.6723	−0.0188	0.063*
C8	0.59118 (17)	0.58160 (15)	0.20439 (19)	0.0324 (4)
H8A	0.5800	0.5160	0.2740	0.039*
H8B	0.5504	0.6592	0.2168	0.039*
N1	0.77548 (14)	0.25062 (11)	0.16597 (15)	0.0289 (3)
O1	0.98688 (13)	0.31280 (11)	0.32386 (15)	0.0441 (3)
O2	0.58963 (13)	0.15423 (11)	−0.00275 (15)	0.0408 (3)
O3	0.70452 (12)	0.35922 (9)	0.17939 (13)	0.0319 (3)
O4	0.79410 (13)	0.42090 (11)	−0.03174 (14)	0.0402 (3)

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
C1	0.0440 (10)	0.0246 (8)	0.0283 (8)	0.0082 (7)	0.0076 (7)	−0.0019 (7)
C2	0.0377 (9)	0.0288 (9)	0.0328 (8)	0.0099 (7)	0.0108 (7)	0.0026 (7)
C3	0.0382 (9)	0.0269 (9)	0.0264 (8)	0.0032 (7)	0.0097 (7)	0.0037 (7)
C4	0.0385 (9)	0.0254 (8)	0.0234 (7)	0.0048 (7)	0.0118 (7)	0.0025 (6)
C5	0.0296 (8)	0.0246 (8)	0.0225 (7)	0.0025 (6)	0.0021 (6)	0.0002 (6)
C6	0.0273 (8)	0.0210 (8)	0.0281 (8)	0.0019 (6)	−0.0042 (6)	−0.0022 (6)
C7	0.0430 (10)	0.0295 (9)	0.0516 (11)	0.0068 (8)	0.0064 (8)	0.0112 (8)
C8	0.0356 (9)	0.0258 (8)	0.0321 (8)	0.0068 (7)	−0.0009 (7)	−0.0079 (7)
N1	0.0389 (8)	0.0183 (7)	0.0296 (7)	0.0104 (5)	0.0078 (6)	0.0001 (5)
O1	0.0487 (8)	0.0335 (7)	0.0470 (7)	−0.0019 (6)	0.0033 (6)	−0.0072 (6)
O2	0.0366 (7)	0.0415 (7)	0.0429 (7)	0.0065 (5)	0.0053 (6)	−0.0038 (6)
O3	0.0460 (7)	0.0209 (6)	0.0323 (6)	0.0125 (5)	0.0164 (5)	0.0030 (5)
O4	0.0551 (8)	0.0342 (7)	0.0370 (7)	0.0107 (6)	0.0226 (6)	0.0050 (5)

Geometric parameters (Å, º)

C1—C4	1.502 (2)	C5—O4	1.1894 (18)
C1—C2	1.527 (2)	C5—O3	1.3895 (18)
C1—H1A	0.9900	C5—C6	1.479 (2)
C1—H1B	0.9900	C6—C8	1.322 (2)
C2—C3	1.502 (2)	C6—C7	1.497 (2)
C2—H2A	0.9900	C7—H7A	0.9800
C2—H2B	0.9900	C7—H7B	0.9800
C3—O1	1.202 (2)	C7—H7C	0.9800
C3—N1	1.380 (2)	C8—H8A	0.9500
C4—O2	1.2005 (19)	C8—H8B	0.9500
C4—N1	1.383 (2)	N1—O3	1.3862 (15)
C4—C1—C2	106.17 (13)	O4—C5—C6	126.43 (14)
C4—C1—H1A	110.5	O3—C5—C6	111.92 (12)
C2—C1—H1A	110.5	C8—C6—C5	121.40 (15)
C4—C1—H1B	110.5	C8—C6—C7	124.80 (15)
C2—C1—H1B	110.5	C5—C6—C7	113.80 (14)
H1A—C1—H1B	108.7	C6—C7—H7A	109.5
C3—C2—C1	105.84 (13)	C6—C7—H7B	109.5
C3—C2—H2A	110.6	H7A—C7—H7B	109.5
C1—C2—H2A	110.6	C6—C7—H7C	109.5
C3—C2—H2B	110.6	H7A—C7—H7C	109.5
C1—C2—H2B	110.6	H7B—C7—H7C	109.5
H2A—C2—H2B	108.7	C6—C8—H8A	120.0
O1—C3—N1	124.12 (15)	C6—C8—H8B	120.0
O1—C3—C2	130.27 (15)	H8A—C8—H8B	120.0
N1—C3—C2	105.60 (13)	C3—N1—C4	117.01 (13)
O2—C4—N1	124.70 (14)	C3—N1—O3	120.89 (13)
O2—C4—C1	130.03 (15)	C4—N1—O3	122.09 (13)
N1—C4—C1	105.28 (13)	N1—O3—C5	111.51 (11)
O4—C5—O3	121.65 (14)
C4—C1—C2—C3	3.14 (16)	O1—C3—N1—O3	−0.2 (2)
C1—C2—C3—O1	179.04 (17)	C2—C3—N1—O3	−179.34 (12)
C1—C2—C3—N1	−1.86 (16)	O2—C4—N1—C3	−177.73 (15)
C2—C1—C4—O2	176.76 (16)	C1—C4—N1—C3	2.28 (18)
C2—C1—C4—N1	−3.24 (16)	O2—C4—N1—O3	1.3 (2)
O4—C5—C6—C8	179.43 (16)	C1—C4—N1—O3	−178.65 (12)
O3—C5—C6—C8	−0.8 (2)	C3—N1—O3—C5	84.50 (16)
O4—C5—C6—C7	0.1 (2)	C4—N1—O3—C5	−94.54 (16)
O3—C5—C6—C7	179.94 (13)	O4—C5—O3—N1	4.8 (2)
O1—C3—N1—C4	178.91 (15)	C6—C5—O3—N1	−175.03 (11)
C2—C3—N1—C4	−0.25 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···O2i	0.98	2.54	3.393 (2)	145

Symmetry code: (i) −x+1, −y+1, −z.