Two substituted 2-pyrrolin-5-ones: Chains built from a single N - H...O hydrogen bond

Article abstract of DOI:10.1107/S0108270107038632

In each of methyl 2-methyl-5-oxo-2-pyrroline-3-carboxyl-ate, C7H9NO3, and 3-acetyl-2-methyl-2-pyrrolin-5-one, C7H9NO2, the pyrrolinone ring is planar. In each structure, mol-ecules are linked into simple chains by way of a single N - H...O hydrogen bond. International Union of Crystallography 2007.

Full text of DOI:10.1107/S0108270107038632

organic compounds
Ê
Acta Crystallographica Section C
Crystal Structure
Communications
1.349 A in ethylenedi(2-pyrrolin-5-one)]. This indicates that
the lone pair of electrons on atom N1 and the ꢀ electrons of
C2 C3 in (I) and (II) exhibit signi®cant delocalization
compared with ethylenedi(2-pyrrolin-5-one).
ISSN 0108-2701
In (I), the exocyclic bond angles show some signi®cant
variations. The two independent exocyclic angles (Table 1) at
atom C2 differ by some 16ꢀ, while those at atom C3 differ by
more than 10ꢀ. The sense of these deviations suggests strongly
repulsive interactions between the methyl group on C2 and
the methoxycarbonyl group, although there is a moderate
intramolecular CÐHÁ Á ÁO hydrogen bond between them
(Table 3). By contrast, the deviations of the angles (Table 4) at
atoms C2 and C3 in (II) become larger, where there is no
intramolecular interaction between methyl and acetyl groups.
The sums of the three angles around atoms C2 and C3 in (I)
are 360.00 (2) and 359.95 (2)ꢀ, respectively, and the corre-
sponding values in (II) are 359.99 (2) and 359.92 (2)ꢀ,
respectively.
Two substituted 2-pyrrolin-5-ones:
chains built from a single NÐHÁ Á ÁO
hydrogen bond
Zhen-Feng Zhang,a* Jian-Ge Wang,b Si-Qian Wangc and
Gui-Rong Qua
aCollege of Chemistry and Environmental Science, Henan Normal University,
Xinxiang 453007, People's Republic of China, bCollege of Chemistry, Luoyang
Normal University, Xinxiang 453007, People's Republic of China, and cInstitute of
Chemistry, Chinese Academy of Sciences, Beijing 100080, People's Republic of
China
It was found that the 1H NMR spectrum of compound (II)
shows the methylene H atoms of the pyrrolinone ring as a
doublet at ꢁ = 3.34 p.p.m., with an identical coupling constant
(J = 2 Hz) to the C2ÐCH3 H atoms. The feature is, however,
inconsistent with that in (I), where the methylene H atoms
give a quartet with coupling constant J = 2.4 Hz. This suggests
that, even in solution, the methyl group bonded to C2 in (II)
has a stable conformation with respect to the pyrrolinone ring.
In compound (I), the molecules are linked into zigzag
chains by a single NÐHÁ Á ÁO hydrogen bond (Table 2).
Correspondence e-mail: zzf5188@sohu.com
Received 23 July 2007
Accepted 6 August 2007
Online 1 September 2007
In each of methyl 2-methyl-5-oxo-2-pyrroline-3-carboxylate,
C7H9NO3, and 3-acetyl-2-methyl-2-pyrrolin-5-one, C7H9NO2,
the pyrrolinone ring is planar. In each structure, molecules are
linked into simple chains by way of a single NÐHÁ Á ÁO
hydrogen bond.
Comment
As precursors for the synthesis of pyrrole derivatives,
2-pyrrolin-5-one derivatives have been prepared by the reac-
tion of glyoxal with enaminoesters (San Feliciano et al., 1989).
However, pyrrolinones accessible by this method are few in
number. We report here the structures of two such
compounds, namely 2-methyl-3-methoxycarbonyl-2-pyrrolin-
5-one, (I), and 2-methyl-3-acetyl-2-pyrrolin-5-one, (II) (Figs. 1
and 2).
Figure 1
The molecular structure of (I), showing the atom-labelling scheme.
Displacement ellipsoids are drawn at the 50% probability level.
In each molecule, the ®ve-membered ring (N1/C1±C4) is
Ê
planar, with r.m.s deviations from the mean plane of 0.007 A
Ê
for (I) and 0.006 A for (II). Within the pyrrolinone rings in (I)
and (II), the bond distances provide evidence for ꢀ-conjuga-
tion and are different from those in substituted ethylenedi(2-
pyrrolin-5-one) (Zhang et al., 2007). The N1ÐC2 and N1ÐC5
Ê
bonds [1.391 (2) and 1.359 (2) A, respectively, for (I), and
Ê
1.396 (2) and 1.358 (2) A for (II)] are shorter than the corre-
sponding bonds in ethylenedi(2-pyrrolin-5-one) (1.411 and
Ê
1.385 A, respectively). Conversely, the C2ÐC3 bond becomes
Figure 2
The molecular structure of (II), showing the atom-labelling scheme.
Displacement ellipsoids are drawn at the 50% probability level.
Ê
longer [1.385 and 1.411 A in (I) and (II), respectively, versus
Acta Cryst. (2007). C63, o565±o567
DOI: 10.1107/S0108270107038632
# 2007 International Union of Crystallography o565

organic compounds
Heterocyclic atom N1 in the molecule at (x, y, z) acts as a
hydrogen-bond donor to carbonyl atom O1 in the molecule at
1
2
5
2
(2 x, y
,
z), thus forming a C(4) chain (Bernstein et al.,
1995) running along the (1, y, 54) direction and generated by a
5
4
21 screw axis along (1, y, ) (Fig. 3). Four chains of this type
pass through each unit cell; two of these chains, running along
the directions (1, y, 14) and (0, y, 14), are related to one another
by translational symmetry operations and are antiparallel to
1
4
the other two chains, running along the (1, y, 34) and (0, y,
)
directions. There are no direction-speci®c interactions
between adjacent chains.
In a similar way, the supramolecular structure of compound
(II) takes on a simple chain packing. For the sake of simplicity,
we shall omit any consideration of the intermolecular CÐ
HÁ Á ÁO interactions involving a CÐH bond from a methyl
group, which are unlikely to have any structural signi®cance.
The molecules of (II) are connected into in®nite chains by a
single NÐHÁ Á ÁO hydrogen bond (Table 4). Heterocyclic atom
N1 in the molecule at (x, y, z) acts as a hydrogen-bond donor
1
2
3
3
2
to carbonyl atom O1 in the molecule at ( x, y
,
z), so
generating a C(4) chain running along the (0, y, ) direction
4
3
4
Figure 4
Part of the crystal structure of (II), showing the formation of a C(4) chain
and generated by a 21 screw axis along (0, y, ) (Fig. 4). Four
such chains pass through each unit cell; two of these chains,
running along the directions (0, y, 34) and (1, y, 41), are related to
one another by inversion and are hence antiparallel. There are
no direction-speci®c interactions between adjacent chains.
running along the (0, y, 34 ) direction. For the sake of clarity, H atoms not
involved in the motif shown have been omitted. Atoms marked with an
1
2
asterisk (*) or an ampersand (&) are at the symmetry positions ( x, y
3
,
1
3
z) and ( x, + y,
z), respectively.
2
2
2
Experimental
Rather than the published method of San Feliciano et al. (1989), a
modi®cation of the synthetic procedure was used to prepare (I) and
(II). For the synthesis of (I), methyl ꢂ-aminocrotonate (23 g) and
excess glyoxal (40% in water, 25 ml) were mixed at room tempera-
ture in water (80 ml). The mixture was then allowed to stand over-
night to give red crystals of (I) (yield 26%). The product was
1
recrystallized from ethyl acetate. H NMR (CDCl3): ꢁ 7.76 (s, 1H,
NH), 3.71 (s, 3H, COOCH3), 3.28 (q, J = 2.4 Hz, 2H, CH2), 2.35 (t, J =
2.4 Hz, 3H, CH3). For the synthesis of (II), excess aqueous ammonia
(17%, 0.22 mol) was introduced into a stirred solution of 2,4-pen-
tanedione (20 g, 0.2 mol) in water (80 ml) at room temperature. After
2 h, excess glyoxal (40% in water, 25 ml) was added with stirring and
the mixture was allowed to stand overnight to give red crystals of (II)
1
(yield 23%). The product was recrystallized from ethyl acetate. H
NMR (CDCl3): ꢁ 7.28 (s, 1H, NH), 3.34 (d, J = 2 Hz, 2H, CH2), 2.38 (t,
J = 2 Hz, 3H, CH3), 2.20 (s, 3H, COCH3).
Compound (I)
Crystal data
3
Ê
C7H9NO3
Mr = 155.15
V = 737.4 (3) A
Z = 4
Monoclinic, P21=c
Mo Kꢃ radiation
ꢄ = 0.11 mm
T = 291 (2) K
0.36 Â 0.32 Â 0.23 mm
1
Ê
a = 12.377 (3) A
Ê
b = 7.562 (2) A
Ê
c = 7.880 (2) A
ꢂ = 91.509 (3)ꢀ
Data collection
Figure 3
Part of the crystal structure of (I), showing the formation of a C(4) chain
Bruker SMART CCD area-detector
diffractometer
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
Tmin = 0.958, Tmax = 0.975
5325 measured re¯ections
1371 independent re¯ections
1095 re¯ections with I > 2ꢅ(I)
Rint = 0.045
running along the (1, y, 54) direction. Atoms marked with an asterisk (*) or
1
2
5
2
an ampersand (&) are at the symmetry positions (2 x, y
5
,
z) and
(2 x, 12 + y,
z), respectively.
2
ꢁ
o566 Zhang et al. C7H9NO3 and C7H9NO2
Acta Cryst. (2007). C63, o565±o567

organic compounds
Re®nement
Table 3
Selected geometric parameters (A, ) for (II).
ꢀ
Ê
R[F2 > 2ꢅ(F2)] = 0.048
wR(F2) = 0.142
S = 1.31
102 parameters
H-atom parameters constrained
3
O1ÐC5
1.2255 (18)
Ê
Áꢆmax = 0.24 e A
3
Ê
0.24 e A
1371 re¯ections
Áꢆmin
=
C5ÐN1ÐC2
C3ÐC2ÐC1
N1ÐC2ÐC1
C2ÐC3ÐC6
112.43 (12)
134.51 (14)
116.02 (13)
130.91 (14)
C6ÐC3ÐC4
C3ÐC4ÐC5
O1ÐC5ÐN1
O1ÐC5ÐC4
120.68 (13)
103.21 (12)
124.12 (14)
129.35 (14)
Table 1
Selected bond and torsion angles (ꢀ) for (I).
C5ÐN1ÐC2
C3ÐC2ÐC1
N1ÐC2ÐC1
C2ÐC3ÐC6
C6ÐC3ÐC4
112.74 (14)
133.14 (17)
117.68 (15)
130.69 (16)
120.47 (15)
C3ÐC4ÐC5
O1ÐC5ÐN1
O1ÐC5ÐC4
N1ÐC5ÐC4
103.09 (14)
124.57 (16)
129.27 (15)
106.16 (14)
C5ÐN1ÐC2ÐC3
C5ÐN1ÐC2ÐC1
N1ÐC2ÐC3ÐC6
N1ÐC2ÐC3ÐC4
C1ÐC2ÐC3ÐC4
1.20 (18)
178.13 (13)
176.86 (14)
0.13 (16)
C2ÐC3ÐC4ÐC5
C3ÐC4ÐC5ÐO1
C3ÐC4ÐC5ÐN1
C2ÐC3ÐC6ÐO2
C4ÐC3ÐC6ÐC7
0.82 (15)
177.87 (16)
1.49 (15)
174.52 (17)
179.34 (13)
179.03 (17)
C5ÐN1ÐC2ÐC3
C5ÐN1ÐC2ÐC1
N1ÐC2ÐC3ÐC6
N1ÐC2ÐC3ÐC4
C2ÐC3ÐC4ÐC5
1.4 (2)
C3ÐC4ÐC5ÐO1
C7ÐO3ÐC6ÐO2
C2ÐC3ÐC6ÐO2
C4ÐC3ÐC6ÐO2
C4ÐC3ÐC6ÐO3
177.99 (18)
0.9 (2)
176.11 (17)
1.0 (2)
179.34 (14)
178.83 (15)
177.45 (15)
0.10 (19)
Table 4
Hydrogen-bond geometry (A, ) for (II).
ꢀ
Ê
1.00 (16)
DÐHÁ Á ÁA
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
N1ÐH1Á Á ÁO1i
Symmetry code: (i) x; y
0.86
1.98
2.819 (2)
166
Table 2
Hydrogen-bond geometry (A, ) for (I).
ꢀ
Ê
1
;
z ‡ 32.
2
DÐHÁ Á ÁA
N1ÐH1Á Á ÁO1i
Symmetry code: (i) x ‡ 2; y
DÐH
HÁ Á ÁA
DÁ Á ÁA
DÐHÁ Á ÁA
For both compounds, data collection: SMART (Bruker, 1997); cell
re®nement: SMART; data reduction: SAINT (Bruker, 1997);
program(s) used to solve structure: SHELXS97 (Sheldrick, 1997a);
program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997a);
molecular graphics: SHELXTL (Sheldrick, 1997b); software used to
prepare material for publication: SHELXTL.
0.86
1.99
2.832 (2)
168
1
2
;
z ‡ 52.
Compound (II)
Crystal data
The authors are grateful to the Physiochemical Analysis
Measurement Institute of Chemistry, Luoyang Normal
University. We also acknowledge the Initial Fund for Scienti®c
Research of Henan Normal University.
3
Ê
C7H9NO2
Mr = 139.15
Monoclinic, P21=c
Ê
a = 12.1211 (18) A
V = 693.18 (18) A
Z = 4
Mo Kꢃ radiation
1
ꢄ = 0.10 mm
T = 291 (2) K
Ê
b = 7.5078 (11) A
Ê
c = 7.9542 (12) A
0.47 Â 0.29 Â 0.24 mm
ꢂ = 106.740 (2)ꢀ
Supplementary data for this paper are available from the IUCr electronic
archives (Reference: GD3127). Services for accessing these data are
described at the back of the journal.
Data collection
Bruker SMART CCD area-detector
diffractometer
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
Tmin = 0.954, Tmax = 0.977
4420 measured re¯ections
1289 independent re¯ections
1150 re¯ections with I > 2ꢅ(I)
Rint = 0.013
References
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem.
Int. Ed. Engl. 34, 1555±1573.
Bruker (1997). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin,
USA.
San Feliciano, A., Caballero, E., Pereira, J. A. P. & Puebla, P. (1989). Tetra-
hedron, 45, 6553±6562.
È
Sheldrick, G. M. (1996). SADABS. University of Gottingen, Germany.
Sheldrick, G. M. (1997a). SHELXS97 and SHELXL97. University of
Re®nement
R[F2 > 2ꢅ(F2)] = 0.039
wR(F2) = 0.124
S = 1.08
94 parameters
H-atom parameters constrained
3
Ê
Áꢆmax = 0.23 e A
3
Ê
0.17 e A
1289 re¯ections
Áꢆmin
=
È
Gottingen, Germany.
Sheldrick, G. M. (1997b). SHELXTL. Version 5.10. Bruker AXS Inc.,
H atoms were placed in idealized positions and allowed to ride on
Ê
their respective parent atoms, with CÐH = 0.98 A and NÐH =
Ê
0.86 A, and with Uiso(H) = kUeq(carrier atom), where k = 1.2 for CÐ
H and NÐH groups, and 1.5 for methyl groups.
Madison, Wisconsin, USA.
Zhang, Z.-F., Wang, S.-Q., Li, J.-P. & Qu, G.-R. (2007). Acta Cryst. E63,
o3865.
ꢁ
Acta Cryst. (2007). C63, o565±o567
Zhang et al. C7H9NO3 and C7H9NO2 o567