2-Benzyl-5-(2,5-dioxo-2,5-di­hydro-1H-pyrrol-1-yl)-2,3-di­hydro-1H-iso­indole-1,3-dione

The title compound, C₁₉H₁₂N₂O₄, was synthesized by dehydrative condensation of maleic anhydride and N-benzyl-4-amino­phthal­imide. In the structure, the male­imide ring is rotated by 43.8 (3)° with respect to the phthal­imide plane. The dihedral angle between the mean planes of the phthal­imide and benzyl groups is 91.0 (3)°.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.038
• wR factor = 0.115
• Data-to-parameter ratio = 11.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

N-Substituted maleimides are among such types of organic compounds with numerous applications in synthetic and polymer chemistry. A search of the literature revealed that some N-substituted maleimide have important biological properties, such as, antimicrobial activity (Zentz et al., 2002), antibacterial activity (Filho et al., 1994) and antitumor activity (Kratz et al., 1997). Some phthalimide derivatives had cytotoxicity (Hall et al., 1995) and anti-HIV activity (Van Derpoorten et al., 1997). It was assumed that compounds having both phthalimide and maleimide residues in the same molecule may possess some attractive biological activities. With this in mind, the synthesis and structure determination of the title compound, (I), was undertaken.

The phthalimide group is planar, the mean deviation from the least-squares plane being 0.010 (3) Å. This observation is in good agreement with our previous report in ethyl N-(2-butyl-1,3-dioxo-2,3-dihydro-1H-isoindol-5-yl) carbamate (Shi et al., 2003). The maleimide moiety is also planar, the mean deviation of the atoms from this plane is 0.008 (3) Å. The dihedral angle between the mean planes of the phthalimide plane and maleimide ring is 43.8 (3)°, which is somewhat different from the corresponding angles found in bis(4-maleimidophenyl)methane, viz. 52.1 (1)° (Usman et al., 2003) and N-(4-hydroxyphenyl)maleimide, viz. 52.8 (5)° (Rodriguez et al., 2002). The benzyl group and phthalimide group are folded towards each other, making an angle of 91.0 (2)°.

S2. Experimental

To a stirred solution of maleic anhydride (22 mmol) in 20 ml of acetone was added dropwise a solution of N-benzyl-4-aminophthalimide (20 mmol) in 30 ml of acetone. After an addition time of 1 h, the maleamic acid separated almost immediately at room temperature. After stirring for 3 h to insure complete reaction, 0.3 ml of triethylamine and 4 ml of acetic anhydride was added. The mixture was heated to 323 K and kept at this temperature for 1 h. Then, the mixture was diluted with four volumes of cold water, thereby precipitating (I) as fine white feathery needles. M.p. 426–428 K; IR (KBr): 3080 (C—H), 1730 (C═O) cm⁻¹; ¹H NMR (CDCl₃, p.p.m.): 4.86 (2H, s), 6.93 (2H, s), 7.26–7.43 (5H, m), 7.78 (1H, d), 7.92–7.95 (2H, m). Compound (I) (50 mg) was dissolved in chloroform (15 ml) and the solution was kept at room temperature for 3 d, yielding colorless single crystals.

S3. Refinement

All H atoms were placed in calculated positions with C—H distances of 0.93 (sp²) and 0.97 Å (sp³), and included in the refinement in riding-motion approximation, with U_iso = 1.2U_eq of the carrier atom.

Computing details

Data collection: SMART (Bruker, 1998); cell refinement: SMART; data reduction: SAINT (Bruker, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1998); software used to prepare material for publication: SHELXTL.

Figures

	Fig. 1. The molecular structure of (I), with ellipsoids drawn at the 30% probability level.
	Fig. 2. The crystal structure of (I), viewed along the a axis.

2-Benzyl-5-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)-2,3-dihydro- 1H-isoindole-1,3-dione

Crystal data

C19H12N2O4	Z = 2
Mr = 332.31	F(000) = 344
Triclinic, P1	Dx = 1.428 Mg m^−3 Dm = not mesaured Mg m^−3 Dm measured by none
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.061 (2) Å	Cell parameters from 997 reflections
b = 11.803 (4) Å	θ = 3.1–26.3°
c = 14.186 (5) Å	µ = 0.10 mm^−1
α = 112.607 (6)°	T = 293 K
β = 94.050 (6)°	Plate, colorless
γ = 95.755 (6)°	0.25 × 0.20 × 0.15 mm
V = 772.8 (5) Å^3

Data collection

Bruker SMART CCD diffractometer	2700 independent reflections
Radiation source: fine-focus sealed tube	2082 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.014
ϕ and ω scans	θmax = 25.0°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)	h = −5→6
Tmin = 0.976, Tmax = 0.985	k = −10→14
3218 measured reflections	l = −16→16

Refinement

Refinement on F^2	0 restraints
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.038	w = 1/[σ^2(Fo^2) + (0.0604P)^2 + 0.1101P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.115	(Δ/σ)max < 0.001
S = 1.06	Δρmax = 0.17 e Å^−3
2700 reflections	Δρmin = −0.20 e Å^−3
226 parameters

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.

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

	x	y	z	Uiso*/Ueq
O1	0.2581 (3)	0.95332 (12)	0.03582 (12)	0.0541 (4)
O2	0.1897 (4)	0.53200 (13)	−0.07670 (12)	0.0703 (5)
O3	0.4487 (3)	0.56491 (13)	0.30525 (11)	0.0582 (4)
O4	1.1962 (3)	0.85166 (14)	0.39137 (12)	0.0584 (4)
N1	0.2824 (3)	0.74661 (13)	0.00293 (12)	0.0403 (4)
N2	0.8442 (3)	0.69878 (14)	0.36710 (12)	0.0420 (4)
C1	0.1916 (4)	0.84475 (18)	−0.01689 (15)	0.0420 (5)
C2	−0.0020 (4)	0.7862 (2)	−0.11143 (16)	0.0527 (5)
H2	−0.0946	0.8288	−0.1432	0.063*
C3	−0.0225 (5)	0.6654 (2)	−0.14331 (16)	0.0569 (6)
H3	−0.1313	0.6088	−0.2012	0.068*
C4	0.1553 (4)	0.63295 (18)	−0.07246 (15)	0.0484 (5)
C5	0.4677 (4)	0.76075 (16)	0.08860 (13)	0.0361 (4)
C6	0.6924 (4)	0.85051 (17)	0.11607 (14)	0.0402 (4)
H6	0.7183	0.8992	0.0784	0.048*
C7	0.8772 (4)	0.86784 (17)	0.19883 (15)	0.0417 (5)
H7	1.0280	0.9271	0.2171	0.050*
C8	0.8309 (3)	0.79450 (16)	0.25334 (13)	0.0365 (4)
C9	0.9886 (4)	0.79070 (17)	0.34436 (15)	0.0417 (4)
C10	0.6109 (4)	0.64521 (16)	0.30038 (14)	0.0410 (5)
C11	0.6050 (4)	0.70617 (15)	0.22588 (13)	0.0362 (4)
C12	0.4192 (4)	0.68696 (16)	0.14388 (14)	0.0390 (4)
H12	0.2685	0.6277	0.1261	0.047*
C13	0.9164 (4)	0.67065 (18)	0.45678 (15)	0.0467 (5)
H13A	1.1027	0.7031	0.4827	0.056*
H13B	0.8965	0.5815	0.4360	0.056*
C14	0.7450 (4)	0.72543 (16)	0.54179 (14)	0.0398 (4)
C15	0.6449 (4)	0.65706 (18)	0.59523 (15)	0.0493 (5)
H15	0.6836	0.5767	0.5787	0.059*
C16	0.4883 (5)	0.7074 (2)	0.67279 (17)	0.0575 (6)
H16	0.4224	0.6609	0.7082	0.069*
C17	0.4292 (5)	0.8259 (2)	0.69785 (17)	0.0571 (6)
H17	0.3224	0.8594	0.7497	0.069*
C18	0.5291 (5)	0.89469 (19)	0.64582 (17)	0.0555 (6)
H18	0.4912	0.9752	0.6631	0.067*
C19	0.6849 (4)	0.84494 (18)	0.56838 (16)	0.0491 (5)
H19	0.7506	0.8921	0.5334	0.059*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0522 (9)	0.0411 (8)	0.0706 (10)	0.0046 (6)	−0.0018 (7)	0.0259 (7)
O2	0.0978 (13)	0.0408 (9)	0.0602 (10)	0.0156 (8)	−0.0105 (9)	0.0086 (7)
O3	0.0688 (10)	0.0499 (8)	0.0587 (9)	−0.0105 (7)	−0.0060 (8)	0.0315 (7)
O4	0.0487 (9)	0.0658 (9)	0.0620 (10)	−0.0065 (7)	−0.0096 (8)	0.0328 (8)
N1	0.0458 (9)	0.0388 (8)	0.0371 (9)	0.0079 (7)	0.0026 (7)	0.0156 (7)
N2	0.0480 (10)	0.0419 (9)	0.0388 (9)	0.0056 (7)	0.0007 (7)	0.0196 (7)
C1	0.0394 (11)	0.0477 (12)	0.0465 (11)	0.0083 (8)	0.0080 (9)	0.0259 (9)
C2	0.0520 (13)	0.0617 (14)	0.0506 (13)	0.0093 (10)	−0.0004 (10)	0.0295 (11)
C3	0.0639 (15)	0.0604 (14)	0.0404 (12)	0.0070 (11)	−0.0061 (10)	0.0158 (10)
C4	0.0585 (13)	0.0421 (11)	0.0396 (11)	0.0106 (9)	0.0038 (10)	0.0101 (9)
C5	0.0396 (10)	0.0365 (9)	0.0329 (10)	0.0109 (8)	0.0060 (8)	0.0127 (8)
C6	0.0415 (11)	0.0421 (10)	0.0437 (11)	0.0089 (8)	0.0100 (9)	0.0224 (9)
C7	0.0376 (10)	0.0433 (10)	0.0468 (11)	0.0035 (8)	0.0075 (9)	0.0207 (9)
C8	0.0357 (10)	0.0363 (9)	0.0379 (10)	0.0094 (8)	0.0070 (8)	0.0137 (8)
C9	0.0416 (11)	0.0405 (10)	0.0435 (11)	0.0078 (8)	0.0055 (9)	0.0165 (9)
C10	0.0509 (12)	0.0335 (10)	0.0383 (10)	0.0058 (8)	0.0042 (9)	0.0141 (8)
C11	0.0413 (10)	0.0317 (9)	0.0357 (10)	0.0089 (8)	0.0073 (8)	0.0119 (7)
C12	0.0416 (11)	0.0335 (9)	0.0403 (10)	0.0038 (8)	0.0045 (9)	0.0131 (8)
C13	0.0544 (12)	0.0462 (11)	0.0449 (11)	0.0112 (9)	−0.0012 (9)	0.0241 (9)
C14	0.0421 (11)	0.0402 (10)	0.0354 (10)	0.0019 (8)	−0.0068 (8)	0.0159 (8)
C15	0.0628 (13)	0.0425 (11)	0.0454 (12)	0.0060 (9)	−0.0026 (10)	0.0223 (9)
C16	0.0711 (15)	0.0607 (14)	0.0498 (13)	0.0044 (11)	0.0100 (11)	0.0326 (11)
C17	0.0626 (14)	0.0598 (14)	0.0479 (12)	0.0082 (11)	0.0102 (11)	0.0195 (10)
C18	0.0658 (15)	0.0418 (11)	0.0575 (13)	0.0099 (10)	0.0094 (11)	0.0169 (10)
C19	0.0571 (13)	0.0419 (11)	0.0515 (12)	0.0025 (9)	0.0066 (10)	0.0229 (9)

Geometric parameters (Å, º)

O1—C1	1.207 (2)	C7—H7	0.9300
O2—C4	1.201 (2)	C8—C11	1.390 (3)
O3—C10	1.216 (2)	C8—C9	1.487 (3)
O4—C9	1.203 (2)	C10—C11	1.490 (2)
N1—C1	1.404 (2)	C11—C12	1.374 (3)
N1—C4	1.409 (2)	C12—H12	0.9300
N1—C5	1.427 (2)	C13—C14	1.512 (3)
N2—C10	1.386 (3)	C13—H13A	0.9700
N2—C9	1.400 (2)	C13—H13B	0.9700
N2—C13	1.465 (2)	C14—C19	1.385 (3)
C1—C2	1.484 (3)	C14—C15	1.387 (3)
C2—C3	1.310 (3)	C15—C16	1.381 (3)
C2—H2	0.9300	C15—H15	0.9300
C3—C4	1.484 (3)	C16—C17	1.374 (3)
C3—H3	0.9300	C16—H16	0.9300
C5—C12	1.394 (2)	C17—C18	1.375 (3)
C5—C6	1.395 (3)	C17—H17	0.9300
C6—C7	1.385 (3)	C18—C19	1.376 (3)
C6—H6	0.9300	C18—H18	0.9300
C7—C8	1.379 (2)	C19—H19	0.9300
C1—N1—C4	109.52 (16)	O3—C10—N2	124.77 (17)
C1—N1—C5	124.88 (15)	O3—C10—C11	128.95 (19)
C4—N1—C5	125.56 (15)	N2—C10—C11	106.27 (15)
C10—N2—C9	112.12 (15)	C12—C11—C8	122.29 (16)
C10—N2—C13	123.58 (16)	C12—C11—C10	130.08 (17)
C9—N2—C13	124.05 (17)	C8—C11—C10	107.62 (16)
O1—C1—N1	125.19 (19)	C11—C12—C5	116.69 (17)
O1—C1—C2	128.94 (18)	C11—C12—H12	121.7
N1—C1—C2	105.85 (16)	C5—C12—H12	121.7
C3—C2—C1	109.50 (19)	N2—C13—C14	112.12 (15)
C3—C2—H2	125.2	N2—C13—H13A	109.2
C1—C2—H2	125.2	C14—C13—H13A	109.2
C2—C3—C4	109.33 (19)	N2—C13—H13B	109.2
C2—C3—H3	125.3	C14—C13—H13B	109.2
C4—C3—H3	125.3	H13A—C13—H13B	107.9
O2—C4—N1	125.68 (19)	C19—C14—C15	118.46 (18)
O2—C4—C3	128.52 (19)	C19—C14—C13	120.88 (17)
N1—C4—C3	105.80 (17)	C15—C14—C13	120.66 (16)
C12—C5—C6	121.51 (17)	C16—C15—C14	120.48 (18)
C12—C5—N1	119.82 (16)	C16—C15—H15	119.8
C6—C5—N1	118.66 (16)	C14—C15—H15	119.8
C7—C6—C5	120.71 (17)	C17—C16—C15	120.34 (19)
C7—C6—H6	119.6	C17—C16—H16	119.8
C5—C6—H6	119.6	C15—C16—H16	119.8
C8—C7—C6	117.98 (17)	C16—C17—C18	119.6 (2)
C8—C7—H7	121.0	C16—C17—H17	120.2
C6—C7—H7	121.0	C18—C17—H17	120.2
C7—C8—C11	120.81 (17)	C19—C18—C17	120.32 (19)
C7—C8—C9	130.76 (17)	C19—C18—H18	119.8
C11—C8—C9	108.42 (16)	C17—C18—H18	119.8
O4—C9—N2	125.07 (18)	C18—C19—C14	120.81 (19)
O4—C9—C8	129.39 (18)	C18—C19—H19	119.6
N2—C9—C8	105.54 (16)	C14—C19—H19	119.6
C4—N1—C1—O1	177.81 (18)	C11—C8—C9—N2	−0.35 (19)
C5—N1—C1—O1	−0.1 (3)	C9—N2—C10—O3	−178.54 (18)
C4—N1—C1—C2	−0.6 (2)	C13—N2—C10—O3	−4.1 (3)
C5—N1—C1—C2	−178.44 (16)	C9—N2—C10—C11	1.1 (2)
O1—C1—C2—C3	−178.1 (2)	C13—N2—C10—C11	175.54 (15)
N1—C1—C2—C3	0.2 (2)	C7—C8—C11—C12	0.4 (3)
C1—C2—C3—C4	0.2 (2)	C9—C8—C11—C12	−179.78 (15)
C1—N1—C4—O2	−179.8 (2)	C7—C8—C11—C10	−178.84 (15)
C5—N1—C4—O2	−2.0 (3)	C9—C8—C11—C10	1.02 (19)
C1—N1—C4—C3	0.7 (2)	O3—C10—C11—C12	−0.8 (3)
C5—N1—C4—C3	178.54 (17)	N2—C10—C11—C12	179.56 (17)
C2—C3—C4—O2	180.0 (2)	O3—C10—C11—C8	178.33 (19)
C2—C3—C4—N1	−0.5 (2)	N2—C10—C11—C8	−1.33 (19)
C1—N1—C5—C12	135.55 (18)	C8—C11—C12—C5	0.1 (2)
C4—N1—C5—C12	−42.0 (2)	C10—C11—C12—C5	179.06 (16)
C1—N1—C5—C6	−43.3 (2)	C6—C5—C12—C11	−0.7 (2)
C4—N1—C5—C6	139.11 (19)	N1—C5—C12—C11	−179.56 (15)
C12—C5—C6—C7	0.9 (3)	C10—N2—C13—C14	−71.9 (2)
N1—C5—C6—C7	179.81 (15)	C9—N2—C13—C14	101.8 (2)
C5—C6—C7—C8	−0.5 (3)	N2—C13—C14—C19	−43.1 (3)
C6—C7—C8—C11	−0.1 (3)	N2—C13—C14—C15	137.13 (18)
C6—C7—C8—C9	−179.96 (17)	C19—C14—C15—C16	0.2 (3)
C10—N2—C9—O4	179.28 (19)	C13—C14—C15—C16	−180.0 (2)
C13—N2—C9—O4	4.9 (3)	C14—C15—C16—C17	0.1 (3)
C10—N2—C9—C8	−0.53 (19)	C15—C16—C17—C18	−0.6 (3)
C13—N2—C9—C8	−174.90 (15)	C16—C17—C18—C19	0.7 (3)
C7—C8—C9—O4	−0.3 (3)	C17—C18—C19—C14	−0.3 (3)
C11—C8—C9—O4	179.9 (2)	C15—C14—C19—C18	−0.1 (3)
C7—C8—C9—N2	179.50 (17)	C13—C14—C19—C18	−179.9 (2)