Isoquinolin-1(2H)-one

The molecule of the title compound, C₉H₇NO, is nearly planar, with an r.m.s. deviation of 0.018 (7) Å. In the crystal structure, two mol­ecules form an R₂²(8) centrosymmetric dimer through N—H...O hydrogen bonds. The three-dimensional packing is additionally stabilized through weak C—H...O inter­actions.

Key indicators

• Single-crystal X-ray study
• T = 290 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.042
• wR factor = 0.123
• Data-to-parameter ratio = 16.6

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT480_ALERT_4_C Long H...A H-Bond Reported H8     ..  O       ..       2.66 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H9     ..  O       ..       2.65 Ang.

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

   0 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
   0 ALERT type 3 Indicator that the structure quality may be low
   2 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Isoquinolines are important from both technological and applied points of view as a part of a significant class of compounds with a variety of pharmacological applications in anticancer, retroviral infections, rheumatoid arthritis and diabets treatment (Jayaraman et al., 2000; Zhang et al., 1997; Bernan et al., 1994; Koleva et al., 1998).

As part of our research on isoquinoline derivatives the structures of (3RS,4RS)-3-(2-furyl)-2-phenethyl-4-(pyrrolidin-1-ylcarbonyl)-3,4- dihydroisoquinolin-1(2H)-one (Petrova et al., 2005) and 1,2,3,4-tetrahydroisoquinolinium hydrogensquarate (Kolev et al., 2007) were reported. The title compound,(I), was investigated in order to provide relevant information on the changes observed upon substitution.

In the asymmetric unit of (I), only one independent molecule is present (Fig. 1). The fused ring system is nearly planar with an r.m.s. deviation of 0.018 (7) Å. The molecules are coupled through bicyclic N—H1···Oⁱ [symmetry code (i): -x + 1, -y + 2, -z + 1] hydrogen bonds and build R²₂(8) dimers (Fig. 2) (Bernstein et al., 1995). The three-dimensional packing is stabilized through weak C8—H8···Oⁱⁱ and C9—H9···Oⁱⁱ interactions [symmetry code (ii): 1/2 + x, 3/2 - y, 1/2 + z].

Related literature

For related literature, see: Bernan et al. (1994); Bernstein et al. (1995); Ferrer et al. (2002); Jayaraman et al. (2000); Kolev et al. (2007); Koleva et al. (1998); Parveen et al. (1999); Petrova et al. (2005); Zhang et al. (1997).

S2. Experimental

Compound (I) was synthesized in a manner similar to the procedure described by Ferrer et al. (2002) and Parveen et al. (1999). Isocoumarin (996 mg, 6.8 mmol) in 2-methoxyethanol (30 ml) was saturated with ammonia for 3 h, after which the mixture was boiled under reflux for 18 h. Subsequent evaporation and recrystallization from ethylacetate yielded the title compound (815 mg, yield 82%). Crystals suitable for X-ray diffraction have been obtained by slow evaporation from hydrazine/water mixture (4:1) at room temperature. IR (KBr pellet, ν, cm^-1): The most intensive band in the IR spectrum is located at 1656 cm^-1 and is characteristic for ν_C═O stretching mode. Skeletal stretching of aromatic ring, ν_C≐C, are detected at 1605, 1549, 1475, 1346 and 1230 cm^-1. The ν_C—H of the phenyl group appears at 551, 669 and 797 cm^-1(m), and in the 2855–3160 cm^-1 (w) region. The weak broad band at 3290 cm^-1 is associated with the N—H group.

S3. Refinement

All H atoms were placed in idealized positions (C—H = 0.93 and N—H = 0.86 Å) and were constrained to ride on their parent atoms, with U_iso(H) = 1.2U_eq(C or N).

Computing details

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); 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) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures

	Fig. 1. View of the molecule and the atom-numbering scheme of (I), showing 50% probability displacement ellipsoids. H atoms are shown as small spheres of arbitrary radii.
	Fig. 2. A view of the molecular packing in (I). All H atoms not involved in hydrogen bonds have been omitted for clarity [symmetry code: (i) -x, 1 - y, -z].

Isoquinolin-1(2H)-one

Crystal data

C9H7NO	F(000) = 304
Mr = 145.16	Dx = 1.373 Mg m^−3
Monoclinic, P21/n	Melting point: not measured K
Hall symbol: -P 2yn	Mo Kα radiation, λ = 0.71073 Å
a = 11.6138 (17) Å	Cell parameters from 22 reflections
b = 5.2965 (9) Å	θ = 18.0–19.2°
c = 12.2946 (9) Å	µ = 0.09 mm^−1
β = 111.745 (9)°	T = 290 K
V = 702.46 (17) Å^3	Prism, pale orange
Z = 4	0.36 × 0.36 × 0.34 mm

Data collection

Enraf–Nonius CAD4 diffractometer	Rint = 0.044
Radiation source: fine-focus sealed tube	θmax = 28.0°, θmin = 2.1°
Graphite monochromator	h = 0→15
ω/2θ scans	k = −6→6
3292 measured reflections	l = −16→15
1678 independent reflections	3 standard reflections every 120 min
1053 reflections with I > 2σ(I)	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)] = 0.042	H-atom parameters constrained
wR(F^2) = 0.123	w = 1/[σ^2(Fo^2) + (0.0535P)^2 + 0.0424P] where P = (Fo^2 + 2Fc^2)/3
S = 1.01	(Δ/σ)max < 0.001
1678 reflections	Δρmax = 0.20 e Å^−3
101 parameters	Δρmin = −0.16 e Å^−3
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 1997), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.033 (5)

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	0.67389 (14)	0.5067 (3)	0.44839 (13)	0.0362 (4)
C2	0.79688 (14)	0.4736 (3)	0.52641 (13)	0.0418 (4)
C3	0.86794 (17)	0.2858 (4)	0.50006 (17)	0.0534 (5)
H3	0.9499	0.2615	0.5497	0.064*
C4	0.81862 (18)	0.1389 (4)	0.40290 (17)	0.0581 (5)
H4	0.8675	0.0161	0.3870	0.070*
C5	0.69666 (18)	0.1697 (4)	0.32727 (16)	0.0525 (5)
H5	0.6636	0.0666	0.2617	0.063*
C6	0.62517 (15)	0.3528 (3)	0.34971 (14)	0.0447 (4)
H6	0.5435	0.3747	0.2988	0.054*
C7	0.59723 (14)	0.7040 (3)	0.46979 (13)	0.0380 (4)
C8	0.77064 (15)	0.8060 (3)	0.64655 (14)	0.0457 (4)
H8	0.8011	0.9065	0.7132	0.055*
C9	0.84330 (15)	0.6297 (4)	0.62860 (15)	0.0485 (5)
H9	0.9238	0.6080	0.6821	0.058*
N	0.65169 (12)	0.8423 (3)	0.56868 (11)	0.0428 (4)
H1N	0.6088	0.9604	0.5835	0.051*
O	0.48896 (10)	0.7471 (2)	0.40287 (10)	0.0481 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.0357 (8)	0.0373 (8)	0.0359 (7)	0.0028 (7)	0.0135 (6)	0.0052 (7)
C2	0.0382 (9)	0.0438 (10)	0.0421 (9)	0.0064 (7)	0.0135 (7)	0.0079 (7)
C3	0.0428 (10)	0.0582 (12)	0.0558 (10)	0.0179 (9)	0.0142 (8)	0.0076 (9)
C4	0.0640 (12)	0.0518 (11)	0.0627 (12)	0.0208 (9)	0.0282 (10)	0.0026 (9)
C5	0.0618 (11)	0.0486 (10)	0.0492 (10)	0.0042 (9)	0.0229 (9)	−0.0052 (8)
C6	0.0429 (9)	0.0477 (10)	0.0411 (9)	0.0019 (8)	0.0128 (7)	0.0018 (7)
C7	0.0357 (8)	0.0403 (9)	0.0357 (8)	0.0020 (7)	0.0108 (7)	0.0032 (7)
C8	0.0413 (9)	0.0498 (10)	0.0376 (8)	0.0020 (8)	0.0049 (7)	−0.0031 (7)
C9	0.0356 (9)	0.0563 (11)	0.0449 (9)	0.0069 (8)	0.0048 (7)	0.0035 (8)
N	0.0379 (7)	0.0452 (8)	0.0408 (7)	0.0091 (6)	0.0094 (6)	−0.0024 (6)
O	0.0344 (6)	0.0548 (8)	0.0457 (6)	0.0113 (5)	0.0039 (5)	−0.0026 (5)

Geometric parameters (Å, º)

C1—C6	1.396 (2)	C5—H5	0.9300
C1—C2	1.406 (2)	C6—H6	0.9300
C1—C7	1.458 (2)	C7—O	1.2423 (18)
C2—C3	1.405 (2)	C7—N	1.358 (2)
C2—C9	1.432 (2)	C8—C9	1.331 (2)
C3—C4	1.362 (3)	C8—N	1.3718 (19)
C3—H3	0.9300	C8—H8	0.9300
C4—C5	1.386 (3)	C9—H9	0.9300
C4—H4	0.9300	N—H1N	0.8600
C5—C6	1.370 (2)
C6—C1—C2	120.15 (15)	C5—C6—C1	120.53 (16)
C6—C1—C7	119.82 (14)	C5—C6—H6	119.7
C2—C1—C7	120.02 (14)	C1—C6—H6	119.7
C3—C2—C1	117.80 (15)	O—C7—N	121.01 (14)
C3—C2—C9	123.28 (15)	O—C7—C1	123.22 (14)
C1—C2—C9	118.92 (15)	N—C7—C1	115.77 (13)
C4—C3—C2	120.99 (17)	C9—C8—N	121.28 (15)
C4—C3—H3	119.5	C9—C8—H8	119.4
C2—C3—H3	119.5	N—C8—H8	119.4
C3—C4—C5	120.97 (17)	C8—C9—C2	119.67 (15)
C3—C4—H4	119.5	C8—C9—H9	120.2
C5—C4—H4	119.5	C2—C9—H9	120.2
C6—C5—C4	119.54 (17)	C7—N—C8	124.31 (14)
C6—C5—H5	120.2	C7—N—H1N	117.8
C4—C5—H5	120.2	C8—N—H1N	117.8
C6—C1—C2—C3	1.2 (2)	C6—C1—C7—O	−1.1 (2)
C7—C1—C2—C3	−178.18 (14)	C2—C1—C7—O	178.23 (15)
C6—C1—C2—C9	−178.33 (16)	C6—C1—C7—N	179.14 (14)
C7—C1—C2—C9	2.3 (2)	C2—C1—C7—N	−1.5 (2)
C1—C2—C3—C4	−0.8 (3)	N—C8—C9—C2	−0.2 (3)
C9—C2—C3—C4	178.67 (18)	C3—C2—C9—C8	179.07 (17)
C2—C3—C4—C5	−0.2 (3)	C1—C2—C9—C8	−1.4 (3)
C3—C4—C5—C6	0.9 (3)	O—C7—N—C8	−179.94 (15)
C4—C5—C6—C1	−0.5 (3)	C1—C7—N—C8	−0.2 (2)
C2—C1—C6—C5	−0.5 (2)	C9—C8—N—C7	1.1 (3)
C7—C1—C6—C5	178.83 (15)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N—H1N···O^i	0.86	1.96	2.818 (2)	172
C8—H8···O^ii	0.93	2.66	3.243 (2)	121
C9—H9···O^ii	0.93	2.65	3.230 (2)	121

Symmetry codes: (i) −x+1, −y+2, −z+1; (ii) x+1/2, −y+3/2, z+1/2.