Diethyl 1-(4-fluoro­phenyl)-3-(2-furyl)-5-oxopyrrolidine-2,2-di­carboxyl­ate and diethyl 1-(3,4-di­chloro­phenyl)-3-(2-furyl)-5-oxopyrrolidine-2,2-di­carboxyl­ate

The title compounds, C₂₀H₂₀FNO₆ and C₂₀H₁₉Cl₂NO₆, respectively, may exhibit bioactivity. In these compounds, the pyrrolidine ring adopts a conformation intermediate between envelope and half-chair. Only one of the two ethoxy­carbonyl side chains is nearly planar. Centrosymmetric pairs are formed, and the crystal structure is stabilized by weak C—H...O hydrogen bonds and van der Waals interactions.

S1. Comment

Bioactivity of the lactam compounds depends on their ability to acylate several proteins to inhibit the cross-linking of bacterial cell walls (Baldwin et al., 1991), which in turn is dependent on the presense of a suitably substituted and activated lactam ring (Baldwin et al.,1984). It has been observed that N-phenyl-γ-lactam derivatives exhibit Gram-positive and Gram-negative antibacterial activities, and the replacement of the phenyl group by a 2-furyl moiety at the 4-position of the γ-lactam ring causes this compound to be moderately active (Ray et al.,1994). In the variation of N-aryl substituents, the replacement of the N-phenyl by the N-4-chlorophenyl group increased the antibacterial activity significantly (Kar et al.,1998). It has also been found that the introduction of fluorine in the aryl moiety alters the activity of many organic compounds abnormally, by affecting the half life of the drug. The title compounds, (I) and (II), were synthesized in order to obtain novel γ-lactam analogues with potential bioactivity. The crystal structure determinations of (I) and (II) were carried out in order to elucidate their molecular conformation.

Both compounds contain one phenyl ring (C5–C10), one furan ring (C11–C14/O2) and one pyrrolidine ring (C1–C4/N1; Figs. 1 and 2). The pyrrolidine ring is intermediate between envelope and half-chair conformations, with a local pesudo-mirror running through atom C3 and the midpoint of the C1—N1 bond, and a local pseudo-twofold axis running through atom C1 and the midpoint of the C3—C4 bond (Duax et al., 1976). Atom C3 deviates from the mean plane passing through the remaining atoms in the ring by 0.476 Å in (I) and 0.492 Å in (II). The conformation of the pyrrolidin ring is dictated by the existence of intramolecular contacts [C11···O4 = 2.878 (2) Å in (I) and 2.876 (3) Å in (II)]. The distortion of the pyrrolidine ring also affects the N1—C4—C3 ring angle [101.46 (12)° in (I) and 100.97 (16)° in (II)]. The plane of the phenyl group is twisted from the plane of the furan ring by 74.01 (7) and 84.46 (9)° in (I) and (II), respectively. The dihedral angle between the phenyl ring and the pyrrolidine ring is 69.79 (8)° in (I) and 64.05 (8)° in (II), and the angle between the pyrrolidine and furan rings is 56.42 (10)° in (I) and 46.38 (12)° in (II).

In both compounds, one of the ethyl acetate chains is completely extended, with all of the non-H atoms coplanar [the mean deviation from the C4/C15/O3/O4/C16/C17 plane is 0.060 Å for (I) and 0.050 Å for (II)]. The other ethyl acetate chain is twisted, the C18—O6—C19—C20 torsion angle being 96.1 (2)° for (I) and −116.5 (5)° for (II). In this chain in (II), a weak attractive intramolecular contact (O6···H3A =2.35 Å) is found. Also in the twisted ethyl acetate chain, a bit more marked for compound II, Slight disorder, which is more marked in (II), is also apparent at the end of the twisted ethyl acetate chain (C19/C20), as evidenced by the U_eq values and the short C19—C20 distance [1.390 (6) Å for (II); Table 2].

The C11—C12 and C13—C14 distances (Tables 1 and 2) confirm the double-bond character of these linkages. These distances are shorter than those found in the corresponding compounds when the tiophen ring replaces the furan ring. [(I): Usman et al., 2001; (II): Ray et al. 1998] In both compounds, the intermolecular interaction between atoms H14A and O1 shortens the nearest C═C double bond in the furan ring [C13═C14 = 1.309 (4) Å in (I) and 1.316 (5) Å in (II)]. The presence of the F atom in (I) provokes a shortening of the nearest C—C bonds [C7—C8 = 1.351 (3) Å and C8—C9 = 1.361 (3) Å]. On the other hand, a short intermolecular contact between atoms Cl1 and O5 [Cl1···O5 = 3.164 (2) Å] is found in (II). In both compounds centrosymetric pairs are formed. As has been found in related compounds, weak hydrogen bonds (Tables 3 and 4) and van der Waals interactions stabilize the crystal structures (Figs. 3 and 4)

S2. Experimental

The title compounds were synthesized via intermolecular Michael addition, followed by an intramolecular amidification reaction, between diethyl-4-fluoro/3,4-dichloroanilinomalonate (synthesized by the condensation reaction between substituted aniline and bromodiethylmalonate) and 3-(2-furyl)acryloyl chloride in the presence of triethylamine, using dry benzene as solvent. Single crystals were grown by slow evaporation, at room temperature, of a solution of the resulting compound in 2-propanol. Compound (I): colourless solid; m.p. 355–357 K (2-propanol). ¹H NMR (200 MHz, CDCl₃): δ 0.92–1.24 (m, 6H), 2.80–3.13 (dd, 2H,J = 8.8, 16.7 Hz), 3.74–3.86 (m, 1H), 3.91–4.17 (m, 3H), 4.61–4.71 (dd, 1H, J = 8.7, 11.3 Hz), 6.28–6.35 (m, 2H), 7.01–7.09 (m, 1H), 7.21–7.28 (m, 3H), 7.37–7.38 (d, 1H, J = 1.31 Hz). Compound (II): colourless solid; m.p. 353–355 K (2-propanol). ¹H NMR (200 MHz, CDCl₃): δ 0.99–1.06 (t, 6H, J = 7.1 Hz), 2.82–3.12 (dd, 2H, J = 8.8, 16.7 Hz), 3.73–3.85 (m, 1H), 3.98–4.20 (m, 3H), 4.57–4.67 (dd, 1H, J = 8.8, 10.8 Hz), 6.28–6.36 (m, 2H), 7.12–7.17 (dd, 1H, J = 2.4, 8.6 Hz), 7.38–7.46 (m, 3H).

S3. Refinement

All H atoms were placed geometrically and treated as riding on their parent atoms, with aromatic C—H distances of 0.93 Å, methylene C—H distances of 0.97 Å, and methyl C—H distances of 0.96 Å. The U_iso(H) values were set to 1.5U_eq(C) for the methyl H atoms and 1.2U_eq(C) for other C-bound H atoms.

Computing details

For both compounds, data collection: SMART (Siemens, 1995); cell refinement: SAINT (Siemens, 1995); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997). Molecular graphics: SHELXTL (Sheldrick, 1997) for (I); SHELXTL (Sheldrick, 1997a) for (II). For both compounds, software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. A view of (I), showing the atomic numbering scheme and 50% probability displacement ellipsoids.
	Fig. 2. A view of (II), showing the atomic numbering scheme and 50% probability displacement ellipsoids.
	Fig. 3. A packing diagram of (I), viewed along the c axis. H atoms have been omitted for clarity.
	Fig. 4. A packing diagram of (II), viewed along the c axis. H atoms have been omitted for clarity.

(I) Diethyl 1-(4-fluorophenyl)-3-(2-furyl)-5-oxopyrrolidine −2,2-dicarboxylate

Crystal data

C20H20FNO6	Z = 2
Mr = 389.37	F(000) = 408
Triclinic, P1	Dx = 1.319 Mg m^−3
Hall symbol: -P 1	Melting point = 355–357 K
a = 9.582 (3) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.157 (3) Å	Cell parameters from 2470 reflections
c = 11.384 (4) Å	θ = 2.0–28.0°
α = 90.305 (6)°	µ = 0.10 mm^−1
β = 105.358 (6)°	T = 293 K
γ = 112.405 (5)°	Block, colourless
V = 980.6 (5) Å^3	0.39 × 0.36 × 0.22 mm

Data collection

Bruker CCD area-detector diffractometer	4167 independent reflections
Radiation source: fine-focus sealed tube	2936 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.015
ϕ and ω scans	θmax = 27.0°, θmin = 2.2°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −12→12
Tmin = 0.885, Tmax = 0.978	k = −12→12
6019 measured reflections	l = −14→11

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.046	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.130	H-atom parameters constrained
S = 1.03	w = 1/[σ^2(Fo^2) + (0.0644P)^2 + 0.1569P] where P = (Fo^2 + 2Fc^2)/3
4167 reflections	(Δ/σ)max < 0.001
255 parameters	Δρmax = 0.22 e Å^−3
0 restraints	Δρmin = −0.25 e Å^−3

Special details

Experimental. Data was collected using a Siemens SMART CCD based diffractometer operating at room temperature. Data was measured using omega scans of 0.3 degrees per frame for 60 s. A total of 1271 frames were collected. The first 50 frames were recollected at the end of each set of frames. As usual in organic compounds high theta reflections are too weak to be measured.

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 (Ų)

	x	y	z	Uiso*/Ueq
F1	0.4839 (2)	1.69158 (16)	0.20331 (17)	0.1212 (7)
O1	−0.12609 (16)	1.21079 (14)	0.23505 (15)	0.0643 (4)
O2	−0.03167 (19)	0.66550 (14)	0.19518 (14)	0.0675 (4)
O3	0.19164 (17)	1.07698 (14)	0.46584 (11)	0.0557 (4)
O4	0.25249 (14)	0.90995 (13)	0.38829 (10)	0.0454 (3)
O5	0.15804 (16)	0.95687 (17)	0.05851 (12)	0.0655 (4)
O6	0.36412 (14)	1.08679 (15)	0.21550 (11)	0.0539 (3)
N1	0.07687 (15)	1.14449 (13)	0.23426 (12)	0.0355 (3)
C1	−0.0740 (2)	1.11918 (18)	0.23530 (16)	0.0420 (4)
C2	−0.1583 (2)	0.96201 (17)	0.24003 (17)	0.0436 (4)
H2A	−0.2632	0.9252	0.1825	0.052*
H2B	−0.1671	0.9436	0.3219	0.052*
C3	−0.05662 (18)	0.89350 (16)	0.20475 (15)	0.0360 (4)
H3A	−0.0886	0.8751	0.1150	0.043*
C4	0.11306 (17)	1.01679 (16)	0.24659 (13)	0.0324 (3)
C5	0.18628 (19)	1.28553 (16)	0.22720 (15)	0.0382 (4)
C6	0.3174 (2)	1.35984 (19)	0.32375 (18)	0.0533 (5)
H6A	0.3374	1.3182	0.3955	0.064*
C7	0.4195 (3)	1.4963 (2)	0.3143 (2)	0.0683 (6)
H7A	0.5099	1.5463	0.3783	0.082*
C8	0.3852 (3)	1.5555 (2)	0.2103 (2)	0.0751 (7)
C9	0.2567 (3)	1.4849 (2)	0.1131 (2)	0.0812 (7)
H9A	0.2367	1.5284	0.0425	0.097*
C10	0.1561 (2)	1.3470 (2)	0.12134 (18)	0.0572 (5)
H10A	0.0686	1.2962	0.0555	0.069*
C11	−0.0740 (2)	0.75493 (17)	0.25436 (17)	0.0436 (4)
C12	−0.1202 (3)	0.6984 (2)	0.3499 (2)	0.0684 (6)
H12A	−0.1533	0.7387	0.4052	0.082*
C13	−0.1077 (3)	0.5610 (3)	0.3490 (3)	0.0880 (9)
H13A	−0.1325	0.4943	0.4039	0.106*
C14	−0.0549 (3)	0.5479 (2)	0.2565 (3)	0.0841 (8)
H14A	−0.0359	0.4690	0.2356	0.101*
C15	0.19318 (18)	1.00859 (17)	0.38058 (14)	0.0367 (4)
C16	0.3037 (2)	0.8702 (2)	0.51026 (17)	0.0565 (5)
H16A	0.2171	0.8367	0.5464	0.068*
H16B	0.3891	0.9520	0.5635	0.068*
C17	0.3578 (3)	0.7535 (2)	0.4944 (2)	0.0700 (6)
H17A	0.3897	0.7219	0.5725	0.105*
H17B	0.4455	0.7889	0.4608	0.105*
H17C	0.2732	0.6745	0.4395	0.105*
C18	0.21248 (19)	1.01333 (18)	0.16132 (15)	0.0382 (4)
C19	0.4739 (3)	1.1002 (3)	0.1436 (2)	0.0738 (7)
H19A	0.5700	1.0964	0.1959	0.089*
H19B	0.4271	1.0208	0.0786	0.089*
C20	0.5115 (3)	1.2358 (3)	0.0902 (3)	0.0996 (9)
H20A	0.5834	1.2431	0.0433	0.149*
H20B	0.5592	1.3143	0.1547	0.149*
H20C	0.4165	1.2390	0.0377	0.149*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
F1	0.1137 (13)	0.0608 (9)	0.1225 (13)	−0.0275 (9)	0.0205 (10)	0.0290 (8)
O1	0.0553 (8)	0.0426 (7)	0.1133 (12)	0.0296 (7)	0.0382 (8)	0.0200 (7)
O2	0.0892 (11)	0.0470 (8)	0.0707 (9)	0.0375 (8)	0.0142 (8)	0.0005 (7)
O3	0.0799 (9)	0.0605 (8)	0.0369 (7)	0.0364 (7)	0.0205 (6)	0.0065 (6)
O4	0.0527 (7)	0.0531 (7)	0.0397 (6)	0.0320 (6)	0.0116 (5)	0.0128 (5)
O5	0.0571 (8)	0.0914 (11)	0.0423 (8)	0.0225 (8)	0.0162 (6)	−0.0084 (7)
O6	0.0384 (7)	0.0739 (9)	0.0492 (7)	0.0172 (6)	0.0200 (5)	0.0032 (6)
N1	0.0339 (7)	0.0296 (7)	0.0453 (8)	0.0136 (6)	0.0133 (6)	0.0078 (5)
C1	0.0396 (9)	0.0384 (9)	0.0542 (10)	0.0185 (8)	0.0187 (7)	0.0103 (7)
C2	0.0368 (9)	0.0368 (9)	0.0611 (11)	0.0148 (7)	0.0199 (8)	0.0113 (8)
C3	0.0364 (8)	0.0327 (8)	0.0385 (8)	0.0134 (7)	0.0103 (7)	0.0058 (6)
C4	0.0345 (8)	0.0315 (8)	0.0341 (8)	0.0154 (6)	0.0112 (6)	0.0058 (6)
C5	0.0387 (9)	0.0303 (8)	0.0457 (9)	0.0121 (7)	0.0150 (7)	0.0050 (7)
C6	0.0512 (11)	0.0429 (10)	0.0529 (11)	0.0109 (9)	0.0058 (9)	0.0057 (8)
C7	0.0570 (12)	0.0464 (12)	0.0711 (14)	−0.0014 (10)	0.0030 (10)	0.0000 (10)
C8	0.0718 (15)	0.0437 (12)	0.0807 (16)	−0.0078 (11)	0.0211 (12)	0.0152 (11)
C9	0.0887 (17)	0.0573 (13)	0.0648 (14)	−0.0008 (12)	0.0140 (12)	0.0280 (11)
C10	0.0578 (12)	0.0465 (11)	0.0487 (11)	0.0049 (9)	0.0093 (9)	0.0117 (8)
C11	0.0420 (9)	0.0316 (8)	0.0552 (10)	0.0143 (7)	0.0112 (8)	0.0047 (7)
C12	0.0696 (14)	0.0619 (13)	0.0930 (16)	0.0321 (11)	0.0449 (12)	0.0403 (12)
C13	0.0740 (16)	0.0572 (14)	0.132 (2)	0.0217 (13)	0.0348 (16)	0.0571 (16)
C14	0.0899 (19)	0.0357 (11)	0.116 (2)	0.0276 (12)	0.0084 (16)	0.0114 (13)
C15	0.0372 (8)	0.0375 (8)	0.0370 (8)	0.0146 (7)	0.0133 (7)	0.0072 (7)
C16	0.0600 (12)	0.0640 (12)	0.0456 (10)	0.0289 (10)	0.0087 (9)	0.0230 (9)
C17	0.0666 (14)	0.0617 (13)	0.0828 (15)	0.0338 (11)	0.0103 (11)	0.0288 (11)
C18	0.0416 (9)	0.0430 (9)	0.0366 (9)	0.0221 (8)	0.0138 (7)	0.0090 (7)
C19	0.0488 (12)	0.113 (2)	0.0690 (14)	0.0309 (13)	0.0345 (11)	0.0125 (13)
C20	0.0822 (18)	0.120 (2)	0.093 (2)	0.0182 (17)	0.0523 (16)	0.0333 (17)

Geometric parameters (Å, º)

F1—C8	1.362 (2)	C6—H6A	0.9300
O1—C1	1.2120 (19)	C7—C8	1.351 (3)
O2—C14	1.361 (3)	C7—H7A	0.9300
O2—C11	1.365 (2)	C8—C9	1.361 (3)
O3—C15	1.1970 (19)	C9—C10	1.386 (3)
O4—C15	1.3203 (19)	C9—H9A	0.9300
O4—C16	1.459 (2)	C10—H10A	0.9300
O5—C18	1.188 (2)	C11—C12	1.333 (3)
O6—C18	1.320 (2)	C12—C13	1.446 (3)
O6—C19	1.464 (2)	C12—H12A	0.9300
N1—C1	1.371 (2)	C13—C14	1.309 (4)
N1—C5	1.435 (2)	C13—H13A	0.9300
N1—C4	1.4635 (19)	C14—H14A	0.9300
C1—C2	1.498 (2)	C16—C17	1.491 (3)
C2—C3	1.522 (2)	C16—H16A	0.9700
C2—H2A	0.9700	C16—H16B	0.9700
C2—H2B	0.9700	C17—H17A	0.9600
C3—C11	1.486 (2)	C17—H17B	0.9600
C3—C4	1.572 (2)	C17—H17C	0.9600
C3—H3A	0.9800	C19—C20	1.463 (4)
C4—C15	1.534 (2)	C19—H19A	0.9700
C4—C18	1.538 (2)	C19—H19B	0.9700
C5—C10	1.373 (2)	C20—H20A	0.9600
C5—C6	1.376 (2)	C20—H20B	0.9600
C6—C7	1.383 (3)	C20—H20C	0.9600
C14—O2—C11	106.14 (19)	C9—C10—H10A	120.1
C15—O4—C16	116.77 (13)	C12—C11—O2	110.88 (17)
C18—O6—C19	117.65 (15)	C12—C11—C3	132.82 (17)
C1—N1—C5	121.46 (13)	O2—C11—C3	116.28 (15)
C1—N1—C4	113.29 (12)	C11—C12—C13	105.0 (2)
C5—N1—C4	125.19 (12)	C11—C12—H12A	127.5
O1—C1—N1	124.72 (15)	C13—C12—H12A	127.5
O1—C1—C2	127.00 (15)	C14—C13—C12	107.2 (2)
N1—C1—C2	108.26 (13)	C14—C13—H13A	126.4
C1—C2—C3	104.66 (13)	C12—C13—H13A	126.4
C1—C2—H2A	110.8	C13—C14—O2	110.8 (2)
C3—C2—H2A	110.8	C13—C14—H14A	124.6
C1—C2—H2B	110.8	O2—C14—H14A	124.6
C3—C2—H2B	110.8	O3—C15—O4	125.43 (15)
H2A—C2—H2B	108.9	O3—C15—C4	123.41 (15)
C11—C3—C2	113.57 (13)	O4—C15—C4	110.99 (13)
C11—C3—C4	116.31 (13)	O4—C16—C17	106.70 (16)
C2—C3—C4	103.10 (12)	O4—C16—H16A	110.4
C11—C3—H3A	107.8	C17—C16—H16A	110.4
C2—C3—H3A	107.8	O4—C16—H16B	110.4
C4—C3—H3A	107.8	C17—C16—H16B	110.4
N1—C4—C15	111.45 (12)	H16A—C16—H16B	108.6
N1—C4—C18	109.80 (12)	C16—C17—H17A	109.5
C15—C4—C18	112.26 (13)	C16—C17—H17B	109.5
N1—C4—C3	101.46 (12)	H17A—C17—H17B	109.5
C15—C4—C3	109.18 (12)	C16—C17—H17C	109.5
C18—C4—C3	112.22 (13)	H17A—C17—H17C	109.5
C10—C5—C6	120.04 (16)	H17B—C17—H17C	109.5
C10—C5—N1	118.30 (15)	O5—C18—O6	125.00 (15)
C6—C5—N1	121.65 (15)	O5—C18—C4	123.86 (15)
C5—C6—C7	120.14 (18)	O6—C18—C4	111.06 (14)
C5—C6—H6A	119.9	C20—C19—O6	110.4 (2)
C7—C6—H6A	119.9	C20—C19—H19A	109.6
C8—C7—C6	118.61 (19)	O6—C19—H19A	109.6
C8—C7—H7A	120.7	C20—C19—H19B	109.6
C6—C7—H7A	120.7	O6—C19—H19B	109.6
C7—C8—C9	122.71 (19)	H19A—C19—H19B	108.1
C7—C8—F1	118.2 (2)	C19—C20—H20A	109.5
C9—C8—F1	119.1 (2)	C19—C20—H20B	109.5
C8—C9—C10	118.7 (2)	H20A—C20—H20B	109.5
C8—C9—H9A	120.6	C19—C20—H20C	109.5
C10—C9—H9A	120.6	H20A—C20—H20C	109.5
C5—C10—C9	119.75 (18)	H20B—C20—H20C	109.5
C5—C10—H10A	120.1
C5—N1—C1—O1	−2.8 (3)	N1—C5—C10—C9	177.9 (2)
C4—N1—C1—O1	174.55 (17)	C8—C9—C10—C5	1.1 (4)
C5—N1—C1—C2	178.61 (14)	C14—O2—C11—C12	0.8 (2)
C4—N1—C1—C2	−4.03 (19)	C14—O2—C11—C3	179.16 (17)
O1—C1—C2—C3	165.64 (18)	C2—C3—C11—C12	−23.6 (3)
N1—C1—C2—C3	−15.83 (19)	C4—C3—C11—C12	95.8 (2)
C1—C2—C3—C11	154.40 (15)	C2—C3—C11—O2	158.45 (15)
C1—C2—C3—C4	27.67 (16)	C4—C3—C11—O2	−82.10 (19)
C1—N1—C4—C15	−94.87 (16)	O2—C11—C12—C13	−0.9 (2)
C5—N1—C4—C15	82.38 (17)	C3—C11—C12—C13	−178.9 (2)
C1—N1—C4—C18	140.10 (14)	C11—C12—C13—C14	0.7 (3)
C5—N1—C4—C18	−42.65 (19)	C12—C13—C14—O2	−0.2 (3)
C1—N1—C4—C3	21.22 (16)	C11—O2—C14—C13	−0.3 (3)
C5—N1—C4—C3	−161.53 (14)	C16—O4—C15—O3	7.4 (2)
C11—C3—C4—N1	−154.13 (13)	C16—O4—C15—C4	−167.98 (14)
C2—C3—C4—N1	−29.15 (14)	N1—C4—C15—O3	16.6 (2)
C11—C3—C4—C15	−36.38 (17)	C18—C4—C15—O3	140.26 (16)
C2—C3—C4—C15	88.60 (14)	C3—C4—C15—O3	−94.65 (18)
C11—C3—C4—C18	88.74 (16)	N1—C4—C15—O4	−167.88 (12)
C2—C3—C4—C18	−146.29 (13)	C18—C4—C15—O4	−44.24 (17)
C1—N1—C5—C10	−66.6 (2)	C3—C4—C15—O4	80.85 (15)
C4—N1—C5—C10	116.36 (18)	C15—O4—C16—C17	177.24 (15)
C1—N1—C5—C6	112.42 (19)	C19—O6—C18—O5	0.2 (3)
C4—N1—C5—C6	−64.6 (2)	C19—O6—C18—C4	−176.75 (16)
C10—C5—C6—C7	−0.3 (3)	N1—C4—C18—O5	−90.32 (19)
N1—C5—C6—C7	−179.27 (18)	C15—C4—C18—O5	145.12 (17)
C5—C6—C7—C8	1.7 (3)	C3—C4—C18—O5	21.7 (2)
C6—C7—C8—C9	−1.8 (4)	N1—C4—C18—O6	86.63 (16)
C6—C7—C8—F1	178.0 (2)	C15—C4—C18—O6	−37.93 (18)
C7—C8—C9—C10	0.4 (4)	C3—C4—C18—O6	−161.33 (13)
F1—C8—C9—C10	−179.4 (2)	C18—O6—C19—C20	96.1 (2)
C6—C5—C10—C9	−1.2 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2B···O3^i	0.97	2.49	3.457 (2)	174
C14—H14A···O1^ii	0.93	2.43	3.220 (3)	143
C19—H19A···O1^iii	0.97	2.60	3.410 (3)	141

Symmetry codes: (i) −x, −y+2, −z+1; (ii) x, y−1, z; (iii) x+1, y, z.

(II) Diethyl 1-(3,4-dchlorophenyl)-3-(2-furyl)-5-oxopyrrolidine-2,2-dicarboxylate

Crystal data

C20H19Cl2NO6	Z = 2
Mr = 440.26	F(000) = 456
Triclinic, P1	Dx = 1.394 Mg m^−3
Hall symbol: -P 1	Melting point = 353–355 K
a = 9.5478 (9) Å	Mo Kα radiation, λ = 0.71073 Å
b = 10.2319 (9) Å	Cell parameters from 2877 reflections
c = 12.5088 (11) Å	θ = 2.0–28.0°
α = 72.749 (2)°	µ = 0.35 mm^−1
β = 86.206 (2)°	T = 298 K
γ = 64.310 (2)°	Block, colourless
V = 1048.91 (16) Å^3	0.23 × 0.19 × 0.15 mm

Data collection

Bruker CCD area detector diffractometer	4450 independent reflections
Radiation source: fine-focus sealed tube	3184 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.018
phi and ω scans	θmax = 27.0°, θmin = 1.7°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −12→12
Tmin = 0.875, Tmax = 0.950	k = −13→7
6438 measured reflections	l = −15→15

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.140	H-atom parameters constrained
S = 1.05	w = 1/[σ^2(Fo^2) + (0.0601P)^2 + 0.4142P] where P = (Fo^2 + 2Fc^2)/3
4450 reflections	(Δ/σ)max < 0.001
264 parameters	Δρmax = 0.37 e Å^−3
0 restraints	Δρmin = −0.41 e Å^−3

Special details

Experimental. Data was collected using a Siemens SMART CCD based diffractometer operating at room temperature. Data was measured using omega scans of 0.3 degrees per frame for 60 s. A total of 1271 frames were collected. The first 50 frames were recollected at the end of each set of frames.

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 (Ų)

	x	y	z	Uiso*/Ueq
Cl1	0.48018 (8)	0.71104 (8)	0.48180 (6)	0.0648 (2)
Cl2	0.19057 (11)	1.02484 (10)	0.46814 (8)	0.0985 (4)
O1	0.1938 (2)	0.87834 (19)	0.00114 (14)	0.0600 (5)
O2	0.1639 (2)	0.2812 (2)	0.10045 (16)	0.0604 (5)
O3	0.50154 (19)	0.4559 (2)	0.17934 (16)	0.0586 (5)
O4	0.41958 (18)	0.27495 (18)	0.24500 (14)	0.0527 (4)
O5	0.1940 (2)	0.4423 (3)	0.37959 (15)	0.0745 (6)
O6	−0.0102 (2)	0.5385 (3)	0.25919 (17)	0.0870 (7)
N1	0.2024 (2)	0.6852 (2)	0.15596 (14)	0.0417 (4)
C1	0.1971 (3)	0.7538 (3)	0.04250 (18)	0.0452 (5)
C2	0.1988 (3)	0.6467 (3)	−0.01788 (18)	0.0473 (5)
H2A	0.3002	0.5995	−0.0456	0.057*
H2B	0.1207	0.6996	−0.0807	0.057*
C3	0.1620 (3)	0.5280 (3)	0.06979 (18)	0.0424 (5)
H3A	0.0484	0.5675	0.0703	0.051*
C4	0.2253 (2)	0.5273 (2)	0.18339 (17)	0.0391 (5)
C5	0.2003 (3)	0.7609 (2)	0.23584 (18)	0.0420 (5)
C6	0.3258 (3)	0.7050 (3)	0.31264 (19)	0.0455 (5)
H6A	0.4123	0.6146	0.3147	0.055*
C7	0.3223 (3)	0.7839 (3)	0.38608 (19)	0.0477 (5)
C8	0.1948 (3)	0.9202 (3)	0.3808 (2)	0.0581 (6)
C9	0.0694 (3)	0.9747 (3)	0.3046 (2)	0.0654 (7)
H9A	−0.0165	1.0659	0.3017	0.078*
C10	0.0710 (3)	0.8947 (3)	0.2329 (2)	0.0546 (6)
H10A	−0.0145	0.9306	0.1828	0.066*
C11	0.2222 (3)	0.3815 (3)	0.04416 (19)	0.0455 (5)
C12	0.3202 (3)	0.3247 (3)	−0.0289 (2)	0.0639 (7)
H12A	0.3757	0.3703	−0.0769	0.077*
C13	0.3237 (4)	0.1821 (3)	−0.0198 (3)	0.0783 (9)
H13A	0.3814	0.1163	−0.0609	0.094*
C14	0.2296 (4)	0.1605 (3)	0.0579 (3)	0.0748 (9)
H14A	0.2103	0.0751	0.0809	0.090*
C15	0.3991 (3)	0.4169 (3)	0.20421 (18)	0.0424 (5)
C16	0.5786 (3)	0.1584 (3)	0.2504 (3)	0.0682 (7)
H16A	0.6463	0.1679	0.2991	0.082*
H16B	0.6175	0.1696	0.1762	0.082*
C17	0.5761 (4)	0.0088 (4)	0.2949 (4)	0.0978 (12)
H17A	0.6797	−0.0701	0.2992	0.147*
H17B	0.5091	0.0004	0.2459	0.147*
H17C	0.5378	−0.0013	0.3684	0.147*
C18	0.1366 (3)	0.4932 (3)	0.28685 (19)	0.0456 (5)
C19	−0.1125 (5)	0.5277 (7)	0.3508 (4)	0.131 (2)
H19A	−0.0538	0.4939	0.4220	0.158*
H19B	−0.1969	0.6275	0.3434	0.158*
C20	−0.1741 (6)	0.4272 (6)	0.3504 (5)	0.142 (2)
H20A	−0.2565	0.4387	0.4004	0.213*
H20B	−0.0938	0.3250	0.3748	0.213*
H20C	−0.2145	0.4485	0.2758	0.213*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Cl1	0.0686 (4)	0.0664 (4)	0.0601 (4)	−0.0267 (3)	−0.0157 (3)	−0.0195 (3)
Cl2	0.1109 (7)	0.0846 (6)	0.0944 (6)	−0.0125 (5)	−0.0190 (5)	−0.0597 (5)
O1	0.0856 (13)	0.0478 (10)	0.0493 (10)	−0.0353 (9)	0.0058 (9)	−0.0084 (8)
O2	0.0650 (11)	0.0591 (11)	0.0696 (12)	−0.0392 (9)	0.0051 (9)	−0.0175 (9)
O3	0.0453 (9)	0.0632 (11)	0.0779 (12)	−0.0306 (8)	0.0167 (8)	−0.0274 (9)
O4	0.0488 (9)	0.0462 (9)	0.0588 (10)	−0.0202 (7)	−0.0017 (7)	−0.0092 (8)
O5	0.0713 (12)	0.1050 (16)	0.0385 (10)	−0.0395 (11)	0.0077 (9)	−0.0084 (10)
O6	0.0581 (12)	0.170 (2)	0.0598 (12)	−0.0676 (14)	0.0266 (9)	−0.0485 (14)
N1	0.0486 (10)	0.0433 (10)	0.0365 (9)	−0.0233 (8)	0.0015 (8)	−0.0110 (8)
C1	0.0480 (12)	0.0472 (13)	0.0402 (12)	−0.0224 (10)	0.0039 (9)	−0.0101 (10)
C2	0.0562 (13)	0.0536 (13)	0.0376 (12)	−0.0293 (11)	0.0048 (10)	−0.0133 (10)
C3	0.0418 (11)	0.0517 (13)	0.0395 (11)	−0.0249 (10)	0.0020 (9)	−0.0143 (10)
C4	0.0410 (11)	0.0448 (12)	0.0372 (11)	−0.0240 (9)	0.0039 (8)	−0.0120 (9)
C5	0.0457 (12)	0.0442 (12)	0.0380 (11)	−0.0215 (10)	0.0044 (9)	−0.0121 (9)
C6	0.0474 (12)	0.0422 (12)	0.0458 (12)	−0.0177 (10)	0.0001 (10)	−0.0135 (10)
C7	0.0531 (13)	0.0482 (13)	0.0428 (12)	−0.0238 (11)	−0.0034 (10)	−0.0105 (10)
C8	0.0696 (16)	0.0563 (15)	0.0513 (14)	−0.0228 (13)	0.0007 (12)	−0.0262 (12)
C9	0.0614 (16)	0.0567 (15)	0.0630 (17)	−0.0042 (12)	−0.0040 (13)	−0.0286 (13)
C10	0.0484 (13)	0.0576 (15)	0.0505 (14)	−0.0146 (11)	−0.0028 (10)	−0.0176 (11)
C11	0.0506 (13)	0.0511 (13)	0.0427 (12)	−0.0290 (11)	−0.0011 (10)	−0.0134 (10)
C12	0.0799 (19)	0.0614 (16)	0.0566 (16)	−0.0338 (14)	0.0147 (14)	−0.0234 (13)
C13	0.103 (2)	0.0608 (18)	0.071 (2)	−0.0278 (17)	0.0056 (18)	−0.0316 (15)
C14	0.095 (2)	0.0506 (16)	0.087 (2)	−0.0379 (16)	−0.0075 (18)	−0.0202 (15)
C15	0.0461 (12)	0.0487 (13)	0.0378 (11)	−0.0239 (10)	0.0038 (9)	−0.0154 (9)
C16	0.0575 (16)	0.0576 (16)	0.0765 (19)	−0.0138 (13)	−0.0015 (14)	−0.0181 (14)
C17	0.094 (2)	0.0527 (18)	0.133 (3)	−0.0200 (17)	−0.013 (2)	−0.0218 (19)
C18	0.0499 (13)	0.0536 (13)	0.0423 (13)	−0.0306 (11)	0.0106 (10)	−0.0157 (10)
C19	0.111 (3)	0.269 (6)	0.102 (3)	−0.136 (4)	0.074 (3)	−0.107 (4)
C20	0.167 (5)	0.142 (4)	0.153 (4)	−0.104 (4)	0.095 (4)	−0.053 (3)

Geometric parameters (Å, º)

Cl1—C7	1.731 (2)	C6—C7	1.381 (3)
Cl2—C8	1.729 (2)	C6—H6A	0.9300
O1—C1	1.212 (3)	C7—C8	1.384 (3)
O2—C11	1.368 (3)	C8—C9	1.382 (4)
O2—C14	1.370 (3)	C9—C10	1.377 (3)
O3—C15	1.199 (3)	C9—H9A	0.9300
O4—C15	1.317 (3)	C10—H10A	0.9300
O4—C16	1.459 (3)	C11—C12	1.334 (4)
O5—C18	1.181 (3)	C12—C13	1.416 (4)
O6—C18	1.306 (3)	C12—H12A	0.9300
O6—C19	1.466 (4)	C13—C14	1.316 (5)
N1—C1	1.378 (3)	C13—H13A	0.9300
N1—C5	1.429 (3)	C14—H14A	0.9300
N1—C4	1.466 (3)	C16—C17	1.476 (4)
C1—C2	1.499 (3)	C16—H16A	0.9700
C2—C3	1.526 (3)	C16—H16B	0.9700
C2—H2A	0.9700	C17—H17A	0.9600
C2—H2B	0.9700	C17—H17B	0.9600
C3—C11	1.481 (3)	C17—H17C	0.9600
C3—C4	1.577 (3)	C19—C20	1.390 (6)
C3—H3A	0.9800	C19—H19A	0.9700
C4—C15	1.535 (3)	C19—H19B	0.9700
C4—C18	1.535 (3)	C20—H20A	0.9600
C5—C10	1.383 (3)	C20—H20B	0.9600
C5—C6	1.385 (3)	C20—H20C	0.9600
C11—O2—C14	105.9 (2)	C5—C10—H10A	120.2
C15—O4—C16	116.20 (19)	C12—C11—O2	109.5 (2)
C18—O6—C19	117.2 (3)	C12—C11—C3	133.4 (2)
C1—N1—C5	121.07 (18)	O2—C11—C3	117.0 (2)
C1—N1—C4	113.36 (17)	C11—C12—C13	107.1 (3)
C5—N1—C4	125.31 (17)	C11—C12—H12A	126.4
O1—C1—N1	124.8 (2)	C13—C12—H12A	126.4
O1—C1—C2	127.2 (2)	C14—C13—C12	106.7 (3)
N1—C1—C2	107.91 (19)	C14—C13—H13A	126.7
C1—C2—C3	104.95 (18)	C12—C13—H13A	126.7
C1—C2—H2A	110.8	C13—C14—O2	110.7 (3)
C3—C2—H2A	110.8	C13—C14—H14A	124.6
C1—C2—H2B	110.8	O2—C14—H14A	124.6
C3—C2—H2B	110.8	O3—C15—O4	125.0 (2)
H2A—C2—H2B	108.8	O3—C15—C4	123.5 (2)
C11—C3—C2	112.61 (19)	O4—C15—C4	111.28 (18)
C11—C3—C4	117.58 (18)	O4—C16—C17	107.8 (3)
C2—C3—C4	102.83 (16)	O4—C16—H16A	110.1
C11—C3—H3A	107.8	C17—C16—H16A	110.1
C2—C3—H3A	107.8	O4—C16—H16B	110.1
C4—C3—H3A	107.8	C17—C16—H16B	110.1
N1—C4—C15	111.08 (17)	H16A—C16—H16B	108.5
N1—C4—C18	108.84 (17)	C16—C17—H17A	109.5
C15—C4—C18	110.97 (18)	C16—C17—H17B	109.5
N1—C4—C3	100.97 (16)	H17A—C17—H17B	109.5
C15—C4—C3	108.53 (17)	C16—C17—H17C	109.5
C18—C4—C3	116.04 (17)	H17A—C17—H17C	109.5
C10—C5—C6	120.2 (2)	H17B—C17—H17C	109.5
C10—C5—N1	118.38 (19)	O5—C18—O6	125.3 (2)
C6—C5—N1	121.35 (19)	O5—C18—C4	123.1 (2)
C7—C6—C5	119.9 (2)	O6—C18—C4	111.4 (2)
C7—C6—H6A	120.1	C20—C19—O6	111.6 (4)
C5—C6—H6A	120.1	C20—C19—H19A	109.3
C6—C7—C8	119.8 (2)	O6—C19—H19A	109.3
C6—C7—Cl1	118.98 (18)	C20—C19—H19B	109.3
C8—C7—Cl1	121.20 (18)	O6—C19—H19B	109.3
C9—C8—C7	120.0 (2)	H19A—C19—H19B	108.0
C9—C8—Cl2	119.2 (2)	C19—C20—H20A	109.5
C7—C8—Cl2	120.77 (19)	C19—C20—H20B	109.5
C10—C9—C8	120.4 (2)	H20A—C20—H20B	109.5
C10—C9—H9A	119.8	C19—C20—H20C	109.5
C8—C9—H9A	119.8	H20A—C20—H20C	109.5
C9—C10—C5	119.6 (2)	H20B—C20—H20C	109.5
C9—C10—H10A	120.2
C5—N1—C1—O1	1.7 (3)	Cl2—C8—C9—C10	179.0 (2)
C4—N1—C1—O1	−172.8 (2)	C8—C9—C10—C5	−1.4 (4)
C5—N1—C1—C2	−179.18 (18)	C6—C5—C10—C9	1.9 (4)
C4—N1—C1—C2	6.4 (2)	N1—C5—C10—C9	−176.3 (2)
O1—C1—C2—C3	−166.2 (2)	C14—O2—C11—C12	−0.5 (3)
N1—C1—C2—C3	14.7 (2)	C14—O2—C11—C3	176.5 (2)
C1—C2—C3—C11	−155.48 (18)	C2—C3—C11—C12	11.8 (4)
C1—C2—C3—C4	−27.9 (2)	C4—C3—C11—C12	−107.5 (3)
C1—N1—C4—C15	91.3 (2)	C2—C3—C11—O2	−164.31 (19)
C5—N1—C4—C15	−82.8 (2)	C4—C3—C11—O2	76.4 (2)
C1—N1—C4—C18	−146.20 (18)	O2—C11—C12—C13	0.6 (3)
C5—N1—C4—C18	39.6 (3)	C3—C11—C12—C13	−175.7 (3)
C1—N1—C4—C3	−23.6 (2)	C11—C12—C13—C14	−0.4 (4)
C5—N1—C4—C3	162.24 (18)	C12—C13—C14—O2	0.1 (4)
C11—C3—C4—N1	154.83 (18)	C11—O2—C14—C13	0.2 (3)
C2—C3—C4—N1	30.5 (2)	C16—O4—C15—O3	−5.5 (3)
C11—C3—C4—C15	38.0 (2)	C16—O4—C15—C4	169.97 (19)
C2—C3—C4—C15	−86.3 (2)	N1—C4—C15—O3	−13.9 (3)
C11—C3—C4—C18	−87.7 (2)	C18—C4—C15—O3	−135.1 (2)
C2—C3—C4—C18	147.96 (19)	C3—C4—C15—O3	96.3 (2)
C1—N1—C5—C10	62.2 (3)	N1—C4—C15—O4	170.59 (17)
C4—N1—C5—C10	−124.0 (2)	C18—C4—C15—O4	49.4 (2)
C1—N1—C5—C6	−115.9 (2)	C3—C4—C15—O4	−79.3 (2)
C4—N1—C5—C6	57.8 (3)	C15—O4—C16—C17	−178.4 (2)
C10—C5—C6—C7	−0.5 (4)	C19—O6—C18—O5	1.1 (5)
N1—C5—C6—C7	177.7 (2)	C19—O6—C18—C4	−173.7 (3)
C5—C6—C7—C8	−1.5 (4)	N1—C4—C18—O5	−91.7 (3)
C5—C6—C7—Cl1	179.61 (18)	C15—C4—C18—O5	30.8 (3)
C6—C7—C8—C9	2.0 (4)	C3—C4—C18—O5	155.3 (2)
Cl1—C7—C8—C9	−179.1 (2)	N1—C4—C18—O6	83.3 (2)
C6—C7—C8—Cl2	−177.5 (2)	C15—C4—C18—O6	−154.2 (2)
Cl1—C7—C8—Cl2	1.4 (3)	C3—C4—C18—O6	−29.7 (3)
C7—C8—C9—C10	−0.6 (4)	C18—O6—C19—C20	−116.5 (5)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2A···O3^i	0.97	2.43	3.355 (3)	159

Symmetry code: (i) −x+1, −y+1, −z.