7,7a-Dihydro­isoindolo[2,1-a]pyrimidin-12-one

The crystal structure of the title compound, C₁₈H₁₂N₂O, is stabilized by inter­molecular N—H...O hydrogen bonds and C—H...π inter­actions. N—H...O hydrogen bonds generate a C(6) chain. The dihedral angle between the isoindoline group and the naphthalene ring system is 24.96 (12)°.

Key indicators

• Single-crystal X-ray study
• T = 296 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.032
• wR factor = 0.079
• Data-to-parameter ratio = 6.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT063_ALERT_3_C Crystal Probably too Large for Beam Size .......       0.62 mm
PLAT066_ALERT_1_C Predicted and Reported Transmissions Identical .          ?
PLAT089_ALERT_3_C Poor Data / Parameter Ratio (Zmax .LT. 18) .....       6.81

Alert level G
REFLT03_ALERT_4_G Please check that the estimate of the number of Friedel pairs is
            correct. If it is not, please give the correct count in the
            _publ_section_exptl_refinement section of the submitted CIF.
           From the CIF: _diffrn_reflns_theta_max           26.00
           From the CIF: _reflns_number_total               1327
           Count of symmetry unique reflns         1327
           Completeness (_total/calc)            100.00%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured         0
           Fraction of Friedel pairs measured     0.000
           Are heavy atom types Z>Si present         no

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

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

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Computing details

Data collection: X-AREA (Stoe & Cie, 2002); cell refinement: X-AREA; data reduction: X-RED32 (Stoe & Cie, 2002); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

7,7a-dihydroisoindolo[2,1-a]pyrimidin-12-one

Crystal data

C18H12N2O	F(000) = 568
Mr = 272.30	Dx = 1.391 Mg m^−3
Orthorhombic, Pca21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c-2ac	Cell parameters from 12797 reflections
a = 19.8550 (13) Å	θ = 1.8–27.2°
b = 4.7939 (3) Å	µ = 0.09 mm^−1
c = 13.6612 (13) Å	T = 296 K
V = 1300.31 (17) Å^3	Prismatic plate, light brown
Z = 4	0.62 × 0.47 × 0.21 mm

Data collection

Stoe IPDS-2 diffractometer	1327 independent reflections
Radiation source: sealed X-ray tube, 12 x 0.4 mm long-fine focus	1146 reflections with I > 2σ(I)
Plane graphite monochromator	Rint = 0.050
Detector resolution: 6.67 pixels mm^-1	θmax = 26.0°, θmin = 2.1°
ω scans	h = −24→24
Absorption correction: integration (X-RED32; Stoe & Cie, 2002)	k = −5→5
Tmin = 0.945, Tmax = 0.981	l = −16→16
12797 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H atoms treated by a mixture of independent and constrained refinement
R[F^2 > 2σ(F^2)] = 0.032	w = 1/[σ^2(Fo^2) + (0.056P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.079	(Δ/σ)max < 0.001
S = 1.01	Δρmax = 0.11 e Å^−3
1327 reflections	Δρmin = −0.14 e Å^−3
195 parameters	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.022 (3)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 1211 Friedel pairs
Secondary atom site location: difference Fourier map

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	0.25741 (11)	0.1729 (5)	0.16001 (16)	0.0592 (5)
C2	0.20675 (10)	0.0002 (5)	0.21149 (18)	0.0576 (5)
C3	0.16087 (12)	−0.1870 (5)	0.1734 (2)	0.0696 (6)
H3	0.1587	−0.2217	0.1065	0.084*
C4	0.11829 (12)	−0.3209 (6)	0.2381 (2)	0.0749 (7)
H4	0.0873	−0.4499	0.2146	0.090*
C5	0.12113 (11)	−0.2657 (6)	0.3374 (2)	0.0714 (7)
H5	0.0917	−0.3572	0.3795	0.086*
C6	0.16706 (10)	−0.0762 (5)	0.37530 (19)	0.0627 (5)
H6	0.1685	−0.0379	0.4420	0.075*
C7	0.21054 (10)	0.0537 (5)	0.31079 (17)	0.0546 (5)
C8	0.26388 (9)	0.2682 (5)	0.32911 (16)	0.0528 (5)
H8	0.2435	0.4405	0.3539	0.063*
C9	0.37174 (9)	0.3693 (4)	0.39568 (15)	0.0541 (5)
C10	0.41185 (11)	0.3988 (6)	0.47699 (18)	0.0660 (6)
H10	0.4032	0.2940	0.5329	0.079*
C11	0.46593 (11)	0.5871 (6)	0.4757 (2)	0.0753 (7)
H11	0.4921	0.6093	0.5316	0.090*
C12	0.48071 (12)	0.7373 (6)	0.3944 (2)	0.0748 (7)
H12	0.5168	0.8609	0.3953	0.090*
C13	0.44206 (10)	0.7085 (5)	0.3085 (2)	0.0640 (6)
C14	0.45728 (12)	0.8515 (6)	0.2210 (2)	0.0774 (7)
H14	0.4933	0.9755	0.2195	0.093*
C15	0.41992 (14)	0.8102 (6)	0.1386 (2)	0.0817 (8)
H15	0.4315	0.9032	0.0813	0.098*
C16	0.36414 (12)	0.6289 (5)	0.13881 (19)	0.0713 (6)
H16	0.3389	0.6028	0.0822	0.086*
C17	0.34750 (10)	0.4920 (5)	0.22284 (17)	0.0560 (5)
C18	0.38615 (10)	0.5233 (5)	0.30980 (16)	0.0544 (5)
N1	0.29150 (8)	0.3142 (4)	0.23088 (13)	0.0568 (4)
N2	0.31757 (9)	0.1798 (4)	0.39313 (14)	0.0560 (4)
O1	0.26710 (9)	0.1884 (4)	0.07137 (12)	0.0763 (5)
H2	0.3042 (13)	0.131 (5)	0.453 (2)	0.073 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0657 (11)	0.0664 (14)	0.0456 (12)	0.0046 (10)	−0.0029 (9)	−0.0009 (10)
C2	0.0583 (10)	0.0583 (12)	0.0563 (13)	0.0016 (9)	−0.0036 (9)	−0.0056 (10)
C3	0.0703 (12)	0.0699 (16)	0.0688 (15)	−0.0002 (11)	−0.0107 (11)	−0.0100 (12)
C4	0.0633 (12)	0.0677 (15)	0.094 (2)	−0.0060 (11)	−0.0096 (13)	−0.0079 (14)
C5	0.0601 (12)	0.0665 (14)	0.0876 (18)	−0.0036 (11)	0.0045 (12)	0.0045 (13)
C6	0.0582 (11)	0.0654 (13)	0.0646 (13)	0.0001 (10)	0.0050 (9)	0.0008 (11)
C7	0.0579 (11)	0.0526 (11)	0.0532 (12)	0.0033 (8)	0.0013 (9)	−0.0023 (10)
C8	0.0540 (10)	0.0574 (11)	0.0471 (10)	0.0030 (9)	0.0021 (9)	−0.0033 (9)
C9	0.0548 (10)	0.0547 (12)	0.0529 (11)	0.0066 (9)	0.0009 (9)	−0.0078 (10)
C10	0.0654 (12)	0.0744 (16)	0.0584 (13)	0.0058 (11)	−0.0057 (9)	−0.0066 (12)
C11	0.0654 (13)	0.0839 (18)	0.0766 (17)	0.0052 (13)	−0.0126 (11)	−0.0170 (15)
C12	0.0587 (11)	0.0729 (15)	0.0926 (19)	−0.0039 (11)	−0.0041 (13)	−0.0187 (16)
C13	0.0550 (11)	0.0587 (14)	0.0784 (16)	0.0023 (9)	0.0064 (11)	−0.0072 (12)
C14	0.0692 (13)	0.0701 (16)	0.093 (2)	−0.0069 (12)	0.0107 (14)	0.0061 (15)
C15	0.0836 (15)	0.0837 (19)	0.0777 (19)	−0.0093 (14)	0.0135 (13)	0.0162 (15)
C16	0.0740 (13)	0.0783 (16)	0.0617 (15)	−0.0014 (12)	0.0030 (11)	0.0117 (13)
C17	0.0560 (10)	0.0579 (13)	0.0543 (12)	0.0034 (9)	0.0035 (9)	0.0025 (10)
C18	0.0525 (10)	0.0530 (12)	0.0578 (12)	0.0058 (8)	0.0035 (9)	−0.0056 (10)
N1	0.0609 (9)	0.0631 (11)	0.0463 (10)	−0.0038 (8)	−0.0002 (7)	0.0016 (9)
N2	0.0609 (9)	0.0623 (11)	0.0447 (10)	0.0001 (7)	−0.0010 (8)	0.0017 (9)
O1	0.0860 (11)	0.0974 (14)	0.0454 (9)	−0.0036 (9)	−0.0047 (8)	−0.0007 (9)

Geometric parameters (Å, º)

C1—O1	1.228 (3)	C9—C18	1.415 (3)
C1—N1	1.362 (3)	C10—C11	1.403 (4)
C1—C2	1.480 (3)	C10—H10	0.9300
C2—C3	1.381 (3)	C11—C12	1.356 (4)
C2—C7	1.383 (3)	C11—H11	0.9300
C3—C4	1.382 (4)	C12—C13	1.409 (4)
C3—H3	0.9300	C12—H12	0.9300
C4—C5	1.383 (4)	C13—C14	1.411 (4)
C4—H4	0.9300	C13—C18	1.422 (3)
C5—C6	1.387 (4)	C14—C15	1.362 (4)
C5—H5	0.9300	C14—H14	0.9300
C6—C7	1.382 (3)	C15—C16	1.408 (4)
C6—H6	0.9300	C15—H15	0.9300
C7—C8	1.497 (3)	C16—C17	1.363 (3)
C8—N2	1.443 (3)	C16—H16	0.9300
C8—N1	1.466 (3)	C17—N1	1.405 (3)
C8—H8	0.9800	C17—C18	1.422 (3)
C9—C10	1.374 (3)	N2—H2	0.89 (3)
C9—N2	1.408 (3)
O1—C1—N1	126.4 (2)	C11—C10—H10	120.0
O1—C1—C2	127.5 (2)	C12—C11—C10	121.2 (2)
N1—C1—C2	106.14 (19)	C12—C11—H11	119.4
C3—C2—C7	121.8 (2)	C10—C11—H11	119.4
C3—C2—C1	129.2 (2)	C11—C12—C13	120.8 (2)
C7—C2—C1	108.99 (19)	C11—C12—H12	119.6
C4—C3—C2	117.7 (2)	C13—C12—H12	119.6
C4—C3—H3	121.2	C12—C13—C14	122.8 (2)
C2—C3—H3	121.2	C12—C13—C18	118.4 (3)
C3—C4—C5	120.9 (2)	C14—C13—C18	118.8 (2)
C3—C4—H4	119.5	C15—C14—C13	120.9 (2)
C5—C4—H4	119.5	C15—C14—H14	119.6
C4—C5—C6	121.2 (3)	C13—C14—H14	119.6
C4—C5—H5	119.4	C14—C15—C16	121.1 (3)
C6—C5—H5	119.4	C14—C15—H15	119.5
C7—C6—C5	117.9 (2)	C16—C15—H15	119.5
C7—C6—H6	121.1	C17—C16—C15	119.3 (2)
C5—C6—H6	121.1	C17—C16—H16	120.3
C6—C7—C2	120.5 (2)	C15—C16—H16	120.3
C6—C7—C8	130.2 (2)	C16—C17—N1	123.3 (2)
C2—C7—C8	109.26 (19)	C16—C17—C18	121.5 (2)
N2—C8—N1	108.83 (15)	N1—C17—C18	115.19 (18)
N2—C8—C7	114.97 (19)	C9—C18—C13	119.6 (2)
N1—C8—C7	102.40 (17)	C9—C18—C17	121.90 (18)
N2—C8—H8	110.1	C13—C18—C17	118.5 (2)
N1—C8—H8	110.1	C1—N1—C17	129.75 (19)
C7—C8—H8	110.1	C1—N1—C8	112.96 (16)
C10—C9—N2	121.9 (2)	C17—N1—C8	117.29 (17)
C10—C9—C18	119.95 (19)	C9—N2—C8	112.93 (18)
N2—C9—C18	118.06 (18)	C9—N2—H2	112.0 (17)
C9—C10—C11	120.0 (2)	C8—N2—H2	114.5 (17)
C9—C10—H10	120.0
O1—C1—C2—C3	2.3 (4)	C15—C16—C17—C18	−1.5 (4)
N1—C1—C2—C3	−177.9 (2)	C10—C9—C18—C13	−0.2 (3)
O1—C1—C2—C7	−177.2 (2)	N2—C9—C18—C13	−177.58 (18)
N1—C1—C2—C7	2.5 (2)	C10—C9—C18—C17	177.71 (19)
C7—C2—C3—C4	0.0 (3)	N2—C9—C18—C17	0.4 (3)
C1—C2—C3—C4	−179.4 (2)	C12—C13—C18—C9	−1.4 (3)
C2—C3—C4—C5	0.9 (4)	C14—C13—C18—C9	177.4 (2)
C3—C4—C5—C6	−0.5 (4)	C12—C13—C18—C17	−179.4 (2)
C4—C5—C6—C7	−0.7 (4)	C14—C13—C18—C17	−0.6 (3)
C5—C6—C7—C2	1.6 (3)	C16—C17—C18—C9	−176.1 (2)
C5—C6—C7—C8	178.7 (2)	N1—C17—C18—C9	4.5 (3)
C3—C2—C7—C6	−1.3 (3)	C16—C17—C18—C13	1.8 (3)
C1—C2—C7—C6	178.27 (19)	N1—C17—C18—C13	−177.54 (19)
C3—C2—C7—C8	−178.98 (19)	O1—C1—N1—C17	−4.9 (4)
C1—C2—C7—C8	0.6 (2)	C2—C1—N1—C17	175.30 (19)
C6—C7—C8—N2	61.6 (3)	O1—C1—N1—C8	175.0 (2)
C2—C7—C8—N2	−121.0 (2)	C2—C1—N1—C8	−4.8 (2)
C6—C7—C8—N1	179.4 (2)	C16—C17—N1—C1	23.2 (4)
C2—C7—C8—N1	−3.2 (2)	C18—C17—N1—C1	−157.4 (2)
N2—C9—C10—C11	179.0 (2)	C16—C17—N1—C8	−156.7 (2)
C18—C9—C10—C11	1.7 (3)	C18—C17—N1—C8	22.7 (3)
C9—C10—C11—C12	−1.7 (4)	N2—C8—N1—C1	127.15 (19)
C10—C11—C12—C13	0.0 (4)	C7—C8—N1—C1	5.0 (2)
C11—C12—C13—C14	−177.2 (2)	N2—C8—N1—C17	−52.9 (2)
C11—C12—C13—C18	1.5 (4)	C7—C8—N1—C17	−175.05 (17)
C12—C13—C14—C15	177.7 (3)	C10—C9—N2—C8	150.8 (2)
C18—C13—C14—C15	−1.0 (4)	C18—C9—N2—C8	−31.9 (2)
C13—C14—C15—C16	1.5 (4)	N1—C8—N2—C9	56.1 (2)
C14—C15—C16—C17	−0.2 (4)	C7—C8—N2—C9	170.29 (17)
C15—C16—C17—N1	177.9 (2)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2···O1^i	0.89 (3)	2.17 (3)	2.959 (3)	148 (2)
C8—H8···Cg1^ii	0.98	2.80	3.568	136

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