Diethyl pyrrolo[2,1-a]isoquinoline-1,2-dicarboxyl­ate

In the title compound, C₁₈H₁₇NO₄, the indolizine unit is not completely planar. Inter­molecular C—H...O inter­actions help to stabilize the crystal structure.

Key indicators

• Single-crystal X-ray study
• T = 297 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.055
• wR factor = 0.149
• Data-to-parameter ratio = 13.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT220_ALERT_2_C Large Non-Solvent    C     Ueq(max)/Ueq(min) ...       3.40 Ratio
PLAT222_ALERT_3_C Large Non-Solvent    H     Ueq(max)/Ueq(min) ...       3.93 Ratio

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   3 ALERT level C = Check and explain
   0 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   1 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion

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Computing details

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXTL (Sheldrick, 1997); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003).

Diethyl pyrrolo[2,1-a]isoquinoline-1,2-dicarboxylate

Crystal data

C18H17NO4	Z = 2
Mr = 311.33	F(000) = 328
Triclinic, P1	Dx = 1.289 Mg m^−3
Hall symbol: -P 1	Melting point: 120.0 K
a = 7.5960 (15) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.920 (2) Å	Cell parameters from 25 reflections
c = 11.451 (2) Å	θ = 1.8–25.0°
α = 92.27 (3)°	µ = 0.09 mm^−1
β = 98.09 (3)°	T = 297 K
γ = 109.42 (3)°	Block, colorless
V = 802.2 (3) Å^3	0.40 × 0.30 × 0.30 mm

Data collection

Enraf–Nonius CAD-4 diffractometer	2060 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.019
Graphite monochromator	θmax = 25.0°, θmin = 1.8°
ω/2θ scans	h = 0→9
Absorption correction: ψ scan (XCAD4; Harms & Wocadlo, 1995)	k = −11→11
Tmin = 0.964, Tmax = 0.973	l = −13→13
3046 measured reflections	3 standard reflections every 200 reflections
2812 independent reflections	intensity decay: none

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.055	H-atom parameters constrained
wR(F^2) = 0.149	w = 1/[σ^2(Fo^2) + (0.0708P)^2 + 0.3401P] where P = (Fo^2 + 2Fc^2)/3
S = 1.01	(Δ/σ)max < 0.001
2812 reflections	Δρmax = 0.37 e Å^−3
203 parameters	Δρmin = −0.39 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.058 (7)

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
C1	0.6678 (3)	0.8925 (2)	0.63017 (19)	0.0436 (5)
C2	0.5761 (3)	0.8403 (2)	0.51295 (19)	0.0441 (5)
C3	0.6626 (3)	0.9369 (2)	0.43881 (19)	0.0462 (6)
H3A	0.6309	0.9285	0.3567	0.055*
C4	0.9238 (3)	1.1699 (3)	0.4669 (2)	0.0513 (6)
H4A	0.9128	1.1835	0.3866	0.062*
C5	1.0551 (3)	1.2675 (3)	0.5444 (2)	0.0542 (6)
H5A	1.1342	1.3496	0.5176	0.065*
C6	1.0777 (3)	1.2493 (3)	0.6682 (2)	0.0499 (6)
C7	0.9549 (3)	1.1263 (2)	0.7104 (2)	0.0455 (5)
C8	0.8111 (3)	1.0219 (2)	0.62484 (18)	0.0425 (5)
C9	0.9808 (4)	1.1107 (3)	0.8315 (2)	0.0561 (6)
H9A	0.9015	1.0304	0.8603	0.067*
C10	1.1211 (4)	1.2117 (3)	0.9084 (2)	0.0681 (8)
H10A	1.1356	1.1996	0.9889	0.082*
C11	1.2418 (4)	1.3317 (3)	0.8674 (3)	0.0710 (8)
H11A	1.3374	1.3996	0.9202	0.085*
C12	1.2202 (4)	1.3505 (3)	0.7491 (3)	0.0638 (7)
H12A	1.3012	1.4316	0.7222	0.077*
C13	0.6163 (3)	0.8221 (2)	0.7382 (2)	0.0490 (6)
C14	0.4292 (3)	0.7000 (3)	0.4768 (2)	0.0487 (6)
C15	0.3882 (6)	0.7700 (4)	0.8670 (3)	0.0994 (12)
H15A	0.3286	0.6671	0.8481	0.119*
H15B	0.4925	0.7873	0.9317	0.119*
C16	0.2526 (6)	0.8310 (6)	0.9012 (4)	0.144
H16A	0.2038	0.7868	0.9684	0.216*
H16B	0.1506	0.8143	0.8364	0.216*
H16C	0.3134	0.9324	0.9214	0.216*
C17	0.2389 (4)	0.5434 (3)	0.3110 (2)	0.0633 (7)
H17A	0.1213	0.5219	0.3423	0.076*
H17B	0.2930	0.4696	0.3305	0.076*
C18	0.2040 (4)	0.5485 (3)	0.1808 (3)	0.0782 (9)
H18A	0.1180	0.4571	0.1444	0.117*
H18B	0.3213	0.5702	0.1510	0.117*
H18C	0.1499	0.6215	0.1627	0.117*
N1	0.8023 (2)	1.04708 (19)	0.50565 (15)	0.0436 (5)
O1	0.7027 (3)	0.7616 (2)	0.79706 (17)	0.0778 (6)
O2	0.4576 (3)	0.8370 (2)	0.76378 (16)	0.0705 (6)
O3	0.3730 (3)	0.60962 (19)	0.54364 (16)	0.0691 (5)
O4	0.3689 (2)	0.68256 (17)	0.36088 (14)	0.0586 (5)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0454 (12)	0.0445 (12)	0.0459 (12)	0.0205 (10)	0.0104 (10)	0.0059 (10)
C2	0.0429 (12)	0.0471 (13)	0.0468 (13)	0.0207 (11)	0.0088 (10)	0.0047 (10)
C3	0.0484 (13)	0.0535 (14)	0.0407 (12)	0.0230 (11)	0.0068 (10)	0.0039 (10)
C4	0.0539 (14)	0.0566 (15)	0.0496 (13)	0.0225 (12)	0.0168 (11)	0.0164 (11)
C5	0.0492 (14)	0.0521 (14)	0.0629 (15)	0.0152 (12)	0.0178 (12)	0.0129 (12)
C6	0.0431 (13)	0.0533 (14)	0.0581 (14)	0.0212 (11)	0.0131 (11)	0.0034 (11)
C7	0.0432 (12)	0.0486 (13)	0.0489 (13)	0.0211 (11)	0.0078 (10)	0.0030 (10)
C8	0.0441 (12)	0.0492 (13)	0.0423 (12)	0.0242 (11)	0.0121 (10)	0.0080 (10)
C9	0.0603 (16)	0.0568 (15)	0.0504 (14)	0.0204 (13)	0.0048 (12)	0.0056 (11)
C10	0.0693 (18)	0.081 (2)	0.0530 (15)	0.0301 (16)	−0.0014 (13)	0.0010 (14)
C11	0.0565 (17)	0.076 (2)	0.0698 (19)	0.0155 (15)	−0.0038 (14)	−0.0087 (15)
C12	0.0517 (15)	0.0594 (16)	0.0765 (19)	0.0143 (13)	0.0113 (13)	0.0003 (14)
C13	0.0584 (15)	0.0432 (13)	0.0473 (13)	0.0187 (12)	0.0112 (11)	0.0052 (10)
C14	0.0501 (13)	0.0507 (14)	0.0516 (14)	0.0244 (11)	0.0111 (11)	0.0052 (11)
C15	0.121 (3)	0.109 (3)	0.085 (2)	0.040 (2)	0.059 (2)	0.045 (2)
C16	0.131	0.225	0.130	0.091	0.105	0.057
C17	0.0647 (17)	0.0511 (15)	0.0683 (17)	0.0178 (13)	0.0010 (13)	−0.0063 (12)
C18	0.078 (2)	0.083 (2)	0.0676 (18)	0.0267 (17)	−0.0021 (15)	−0.0104 (15)
N1	0.0431 (10)	0.0486 (11)	0.0438 (10)	0.0199 (9)	0.0107 (8)	0.0089 (8)
O1	0.0965 (15)	0.0876 (14)	0.0693 (12)	0.0529 (13)	0.0176 (11)	0.0338 (11)
O2	0.0771 (13)	0.0857 (14)	0.0695 (12)	0.0411 (11)	0.0399 (10)	0.0327 (10)
O3	0.0783 (13)	0.0552 (11)	0.0640 (11)	0.0093 (10)	0.0114 (9)	0.0116 (9)
O4	0.0624 (11)	0.0516 (10)	0.0528 (10)	0.0114 (8)	0.0011 (8)	0.0008 (8)

Geometric parameters (Å, º)

C1—C8	1.389 (3)	C11—C12	1.369 (4)
C1—C2	1.413 (3)	C11—H11A	0.9300
C1—C13	1.481 (3)	C12—H12A	0.9300
C2—C3	1.369 (3)	C13—O1	1.189 (3)
C2—C14	1.464 (3)	C13—O2	1.332 (3)
C3—N1	1.357 (3)	C14—O3	1.210 (3)
C3—H3A	0.9300	C14—O4	1.327 (3)
C4—C5	1.327 (3)	C15—C16	1.445 (5)
C4—N1	1.394 (3)	C15—O2	1.456 (3)
C4—H4A	0.9300	C15—H15A	0.9700
C5—C6	1.430 (3)	C15—H15B	0.9700
C5—H5A	0.9300	C16—H16A	0.9600
C6—C12	1.400 (4)	C16—H16B	0.9600
C6—C7	1.417 (3)	C16—H16C	0.9600
C7—C9	1.394 (3)	C17—O4	1.442 (3)
C7—C8	1.447 (3)	C17—C18	1.483 (4)
C8—N1	1.394 (3)	C17—H17A	0.9700
C9—C10	1.368 (4)	C17—H17B	0.9700
C9—H9A	0.9300	C18—H18A	0.9600
C10—C11	1.385 (4)	C18—H18B	0.9600
C10—H10A	0.9300	C18—H18C	0.9600
C8—C1—C2	107.49 (19)	O1—C13—O2	123.0 (2)
C8—C1—C13	126.9 (2)	O1—C13—C1	126.3 (2)
C2—C1—C13	125.6 (2)	O2—C13—C1	110.68 (19)
C3—C2—C1	107.9 (2)	O3—C14—O4	124.0 (2)
C3—C2—C14	126.1 (2)	O3—C14—C2	124.4 (2)
C1—C2—C14	125.6 (2)	O4—C14—C2	111.6 (2)
N1—C3—C2	108.26 (19)	C16—C15—O2	108.4 (3)
N1—C3—H3A	125.9	C16—C15—H15A	110.0
C2—C3—H3A	125.9	O2—C15—H15A	110.0
C5—C4—N1	120.0 (2)	C16—C15—H15B	110.0
C5—C4—H4A	120.0	O2—C15—H15B	110.0
N1—C4—H4A	120.0	H15A—C15—H15B	108.4
C4—C5—C6	121.5 (2)	C15—C16—H16A	109.5
C4—C5—H5A	119.3	C15—C16—H16B	109.5
C6—C5—H5A	119.3	H16A—C16—H16B	109.5
C12—C6—C7	119.0 (2)	C15—C16—H16C	109.5
C12—C6—C5	121.2 (2)	H16A—C16—H16C	109.5
C7—C6—C5	119.7 (2)	H16B—C16—H16C	109.5
C9—C7—C6	118.6 (2)	O4—C17—C18	107.1 (2)
C9—C7—C8	123.4 (2)	O4—C17—H17A	110.3
C6—C7—C8	118.0 (2)	C18—C17—H17A	110.3
C1—C8—N1	106.44 (19)	O4—C17—H17B	110.3
C1—C8—C7	135.3 (2)	C18—C17—H17B	110.3
N1—C8—C7	118.22 (19)	H17A—C17—H17B	108.5
C10—C9—C7	121.0 (3)	C17—C18—H18A	109.5
C10—C9—H9A	119.5	C17—C18—H18B	109.5
C7—C9—H9A	119.5	H18A—C18—H18B	109.5
C9—C10—C11	120.5 (3)	C17—C18—H18C	109.5
C9—C10—H10A	119.7	H18A—C18—H18C	109.5
C11—C10—H10A	119.7	H18B—C18—H18C	109.5
C12—C11—C10	120.0 (3)	C3—N1—C8	109.89 (18)
C12—C11—H11A	120.0	C3—N1—C4	127.65 (19)
C10—C11—H11A	120.0	C8—N1—C4	122.5 (2)
C11—C12—C6	120.9 (3)	C13—O2—C15	116.5 (2)
C11—C12—H12A	119.6	C14—O4—C17	117.54 (19)
C6—C12—H12A	119.6
C8—C1—C2—C3	−0.2 (2)	C10—C11—C12—C6	−0.3 (4)
C13—C1—C2—C3	178.8 (2)	C7—C6—C12—C11	0.1 (4)
C8—C1—C2—C14	173.5 (2)	C5—C6—C12—C11	−179.5 (2)
C13—C1—C2—C14	−7.5 (3)	C8—C1—C13—O1	−74.0 (3)
C1—C2—C3—N1	−0.6 (2)	C2—C1—C13—O1	107.2 (3)
C14—C2—C3—N1	−174.27 (19)	C8—C1—C13—O2	104.9 (3)
N1—C4—C5—C6	0.8 (4)	C2—C1—C13—O2	−73.8 (3)
C4—C5—C6—C12	178.0 (2)	C3—C2—C14—O3	170.1 (2)
C4—C5—C6—C7	−1.6 (3)	C1—C2—C14—O3	−2.5 (4)
C12—C6—C7—C9	0.0 (3)	C3—C2—C14—O4	−8.1 (3)
C5—C6—C7—C9	179.6 (2)	C1—C2—C14—O4	179.27 (19)
C12—C6—C7—C8	−178.8 (2)	C2—C3—N1—C8	1.2 (2)
C5—C6—C7—C8	0.8 (3)	C2—C3—N1—C4	−178.79 (19)
C2—C1—C8—N1	0.9 (2)	C1—C8—N1—C3	−1.3 (2)
C13—C1—C8—N1	−178.0 (2)	C7—C8—N1—C3	178.66 (18)
C2—C1—C8—C7	−179.0 (2)	C1—C8—N1—C4	178.67 (19)
C13—C1—C8—C7	2.0 (4)	C7—C8—N1—C4	−1.4 (3)
C9—C7—C8—C1	1.8 (4)	C5—C4—N1—C3	−179.4 (2)
C6—C7—C8—C1	−179.4 (2)	C5—C4—N1—C8	0.6 (3)
C9—C7—C8—N1	−178.1 (2)	O1—C13—O2—C15	−2.2 (4)
C6—C7—C8—N1	0.6 (3)	C1—C13—O2—C15	178.8 (2)
C6—C7—C9—C10	0.2 (4)	C16—C15—O2—C13	163.4 (3)
C8—C7—C9—C10	178.9 (2)	O3—C14—O4—C17	−4.8 (3)
C7—C9—C10—C11	−0.4 (4)	C2—C14—O4—C17	173.46 (19)
C9—C10—C11—C12	0.4 (4)	C18—C17—O4—C14	−176.1 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5A···O3^i	0.93	2.59	3.451 (3)	154
C10—H10A···O1^ii	0.93	2.53	3.415 (3)	157

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