2,3-Dihydro­pyrrolo­[2,1-b]quinazoline-9(1H)-thione

In the crystal, mol­ecules of the title compound, C₁₁H₁₀N₂S, are connected by C—H...N inter­actions around threefold axes. Furthermore, they form stacks along the c axis showing π–π inter­actions between pyrimidine rings [centroid–centroid distance = 3.721 (1) Å]. The central ring is essentially planar with an r.m.s. deviation of 0.007 Å. The five-membered ring adopts an envelope conformation with the flap atom deviating by 0.241 (4) Å from the mean plane (r.m.s. deviation = 0.002 Å) through the other four ring atoms.

Key indicators

• Single-crystal X-ray study
• T = 295 K
• Mean [sigma](C-C) = 0.004 Å
• R factor = 0.029
• wR factor = 0.078
• Data-to-parameter ratio = 10.8

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT230_ALERT_2_C Hirshfeld Test Diff for    S1     --  C4      ..        5.9 su
PLAT915_ALERT_3_C Low Friedel Pair Coverage ......................         58 Perc.

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           66.75
           From the CIF: _reflns_number_total               1379
           Count of symmetry unique reflns          878
           Completeness (_total/calc)            157.06%
           TEST3: Check Friedels for noncentro structure
           Estimate of Friedel pairs measured       501
           Fraction of Friedel pairs measured     0.571
           Are heavy atom types Z>Si present        yes
PLAT005_ALERT_5_G No _iucr_refine_instructions_details in CIF ....          ?
PLAT063_ALERT_4_G Crystal Size Likely too Large for Beam Size ....       0.65 mm
PLAT152_ALERT_1_G The Supplied and Calc. Volume s.u. Differ by ...          2 Units
PLAT909_ALERT_3_G Percentage of Observed Data at Theta(Max) still          85 Perc.

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   2 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   5 ALERT level G = General information/check it is not something unexpected

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

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S1. Comment

The title compound was synthesized by the reaction of 2,3-dihydro-1H,9H-pyrrolo[2,1-b]quinazolin-9-one with phosphorus pentasulfide (Figure 1). X-ray single-crystal diffraction study reveals that the title compound crystallizes in the space group R3c with one molecule in the asymmetric unit. The molecule is almost planar (excluding the atom C10) with r.m.s. deviation of 0.014 Å. The central (pyrimidinic) ring is planar with rms deviations of 0.007Å. Conformation of five-membered (pyrrolic) ring is envelope with deviation of the atom C10 (0.241 (4) Å) from mean plane of other four atoms (rms deviations of 0.002 Å) of the ring. In the structure weak C—H···N interactions (Table 1) are observed. The molecules are stacked along the c axis by π–π stacking interactions between pyrimidine rings [centroid-centroid distances = 3.721 (1) Å].

Related literature

For the synthesis of 2,3-dihydro-1H,9H-pyrrolo[2,1-b]quinazolin-9-one and the title compound, see: Abdurazakov et al. (2007); Shakhidoyatov & Kadyrov (1977); Elmuradov et al. (2010). For related structures, see Elmuradov et al. (2010); Turgunov et al. (1995).

S2. Experimental

2.5 g (13 mmole) of 2,3-dihydro-1H,9H-pyrrolo[2,1]quinazolin-9-one was dissolved in 15 ml m-xylene and 2.98 g (13 mmole) of phosphorus pentasulfide were added (Figure 1). Reaction mixture was boiled 2 h and allowed to cool up to room temperature. The precipitate was filtered, flushed with m-xylene (3 ml) and 10% NaOH (50 ml) was added, then the precipittate was filtered and washed with water to get neutral medium and was dried. After recrystallization from hexane 1.96 g (72%) the title compound crystals. Suitable for X-ray diffraction crystals was obtained from hexane with m.p. 138 °C

¹H NMR (400 MHz, CDCl₃): 8.67 (1H, dd, J=8.3, J=1.7, H-8), 7.69 (1H, td, J=8.3, J=1.7, H-6), 7.59 (1H, dd, J=8.3, J=1.2, H-5), 7.43 (1H, td, J=8.3, J=1.2, H-6), 4.47 (2H, t, J=7.5, 1-CH₂), 3.25 (2H, t, J=7.9, 3-CH₂), 2.28 (2H, m, 2-CH₂)

S3. Refinement

H atoms were positioned geometrically and treated as riding on their C atoms, with C—H distances of 0.93 Å (aromatic)and 0.97 Å (CH₂) and were refined with U_iso(H)=1.2Ueq(C).

Computing details

Data collection: CrysAlis PRO (Oxford Diffraction, 2009); cell refinement: CrysAlis PRO (Oxford Diffraction, 2009); data reduction: CrysAlis PRO (Oxford Diffraction, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP (Bruker, 1998); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures

	Fig. 1. Reaction scheme
	Fig. 2. The molecular structure of the title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

2,3-Dihydropyrrolo[2,1-b]quinazoline-9(1H)-thione

Crystal data

C11H10N2S	Dx = 1.366 Mg m^−3
Mr = 202.27	Melting point: 411 K
Trigonal, R3c	Cu Kα radiation, λ = 1.54184 Å
Hall symbol: R 3 -2"c	Cell parameters from 2338 reflections
a = 26.206 (1) Å	θ = 3.4–66.8°
c = 7.441 (2) Å	µ = 2.57 mm^−1
V = 4425.5 (12) Å^3	T = 295 K
Z = 18	Prism, yellow
F(000) = 1908	0.65 × 0.25 × 0.20 mm

Data collection

Oxford Diffraction Xcalibur Ruby diffractometer	1379 independent reflections
Radiation source: Enhance (Cu) X-ray Source	1305 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.021
Detector resolution: 10.2576 pixels mm^-1	θmax = 66.8°, θmin = 3.4°
ω scans	h = −28→31
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009)	k = −31→31
Tmin = 0.601, Tmax = 1.000	l = −8→8
5753 measured reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.029	w = 1/[σ^2(Fo^2) + (0.0613P)^2 + 0.028P] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.078	(Δ/σ)max < 0.001
S = 1.06	Δρmax = 0.16 e Å^−3
1379 reflections	Δρmin = −0.19 e Å^−3
128 parameters	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
1 restraint	Extinction coefficient: 0.00144 (11)
Primary atom site location: structure-invariant direct methods	Absolute structure: Flack (1983), 501 Friedel pairs
Secondary atom site location: difference Fourier map	Absolute structure parameter: −0.003 (19)

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
S1	0.89225 (2)	0.23959 (3)	0.13284 (10)	0.0588 (2)
N1	0.71400 (8)	0.21624 (8)	0.2807 (3)	0.0562 (5)
C2	0.72288 (9)	0.17396 (9)	0.2343 (3)	0.0480 (4)
N3	0.77699 (7)	0.18140 (7)	0.1857 (2)	0.0445 (4)
C4	0.82758 (8)	0.23443 (9)	0.1852 (3)	0.0451 (4)
C4A	0.81976 (9)	0.28375 (9)	0.2345 (3)	0.0477 (4)
C5	0.86723 (10)	0.34181 (10)	0.2392 (4)	0.0614 (5)
H5A	0.9050	0.3495	0.2105	0.074*
C6	0.85814 (13)	0.38726 (11)	0.2857 (5)	0.0765 (8)
H6A	0.8898	0.4256	0.2880	0.092*
C7	0.80209 (14)	0.37644 (12)	0.3296 (5)	0.0827 (9)
H7A	0.7964	0.4076	0.3604	0.099*
C8	0.75527 (11)	0.32025 (12)	0.3276 (5)	0.0746 (7)
H8A	0.7180	0.3135	0.3581	0.090*
C8A	0.76270 (10)	0.27240 (9)	0.2803 (3)	0.0528 (5)
C9	0.67738 (10)	0.11011 (10)	0.2275 (4)	0.0601 (5)
H9A	0.6436	0.1040	0.1570	0.072*
H9B	0.6642	0.0947	0.3475	0.072*
C10	0.70825 (10)	0.08040 (10)	0.1391 (4)	0.0670 (6)
H10A	0.6999	0.0450	0.2044	0.080*
H10B	0.6949	0.0697	0.0161	0.080*
C11	0.77385 (10)	0.12481 (9)	0.1437 (4)	0.0548 (5)
H11A	0.7934	0.1146	0.2356	0.066*
H11B	0.7920	0.1267	0.0283	0.066*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0415 (3)	0.0673 (4)	0.0720 (3)	0.0306 (2)	0.0040 (2)	−0.0012 (3)
N1	0.0407 (8)	0.0548 (10)	0.0767 (12)	0.0265 (8)	−0.0002 (8)	0.0031 (9)
C2	0.0375 (9)	0.0509 (10)	0.0541 (10)	0.0210 (8)	−0.0041 (8)	0.0011 (9)
N3	0.0422 (8)	0.0457 (9)	0.0480 (8)	0.0238 (7)	−0.0023 (6)	0.0014 (7)
C4	0.0420 (9)	0.0512 (11)	0.0442 (9)	0.0250 (9)	−0.0033 (8)	0.0018 (8)
C4A	0.0444 (10)	0.0472 (10)	0.0541 (10)	0.0249 (8)	−0.0033 (8)	0.0033 (9)
C5	0.0499 (11)	0.0504 (11)	0.0791 (14)	0.0215 (9)	−0.0041 (11)	0.0013 (11)
C6	0.0686 (15)	0.0437 (12)	0.110 (2)	0.0229 (12)	−0.0094 (14)	−0.0012 (13)
C7	0.0838 (17)	0.0545 (13)	0.124 (3)	0.0454 (13)	−0.0099 (18)	−0.0084 (15)
C8	0.0615 (14)	0.0649 (14)	0.112 (2)	0.0429 (12)	−0.0006 (15)	−0.0018 (15)
C8A	0.0485 (11)	0.0482 (11)	0.0667 (12)	0.0279 (9)	−0.0062 (10)	0.0009 (9)
C9	0.0429 (10)	0.0519 (11)	0.0752 (13)	0.0160 (9)	−0.0014 (10)	−0.0002 (11)
C10	0.0616 (14)	0.0464 (11)	0.0850 (16)	0.0211 (10)	−0.0043 (13)	−0.0053 (11)
C11	0.0601 (12)	0.0512 (11)	0.0592 (11)	0.0325 (10)	−0.0004 (11)	−0.0029 (12)

Geometric parameters (Å, º)

S1—C4	1.6771 (18)	C6—H6A	0.9300
N1—C2	1.288 (3)	C7—C8	1.366 (4)
N1—C8A	1.384 (3)	C7—H7A	0.9300
C2—N3	1.380 (3)	C8—C8A	1.406 (3)
C2—C9	1.493 (3)	C8—H8A	0.9300
N3—C4	1.359 (3)	C9—C10	1.524 (3)
N3—C11	1.477 (3)	C9—H9A	0.9700
C4—C4A	1.453 (3)	C9—H9B	0.9700
C4A—C5	1.404 (3)	C10—C11	1.520 (3)
C4A—C8A	1.413 (3)	C10—H10A	0.9700
C5—C6	1.371 (4)	C10—H10B	0.9700
C5—H5A	0.9300	C11—H11A	0.9700
C6—C7	1.388 (4)	C11—H11B	0.9700
C2—N1—C8A	116.55 (17)	C7—C8—H8A	119.6
N1—C2—N3	124.32 (18)	C8A—C8—H8A	119.6
N1—C2—C9	125.92 (19)	N1—C8A—C8	118.8 (2)
N3—C2—C9	109.75 (18)	N1—C8A—C4A	122.71 (18)
C4—N3—C2	123.61 (16)	C8—C8A—C4A	118.5 (2)
C4—N3—C11	124.21 (16)	C2—C9—C10	104.87 (19)
C2—N3—C11	112.11 (16)	C2—C9—H9A	110.8
N3—C4—C4A	114.17 (16)	C10—C9—H9A	110.8
N3—C4—S1	120.86 (15)	C2—C9—H9B	110.8
C4A—C4—S1	124.97 (16)	C10—C9—H9B	110.8
C5—C4A—C8A	119.56 (19)	H9A—C9—H9B	108.8
C5—C4A—C4	121.83 (19)	C11—C10—C9	106.58 (18)
C8A—C4A—C4	118.61 (18)	C11—C10—H10A	110.4
C6—C5—C4A	120.2 (2)	C9—C10—H10A	110.4
C6—C5—H5A	119.9	C11—C10—H10B	110.4
C4A—C5—H5A	119.9	C9—C10—H10B	110.4
C5—C6—C7	120.5 (2)	H10A—C10—H10B	108.6
C5—C6—H6A	119.7	N3—C11—C10	104.32 (18)
C7—C6—H6A	119.7	N3—C11—H11A	110.9
C8—C7—C6	120.4 (2)	C10—C11—H11A	110.9
C8—C7—H7A	119.8	N3—C11—H11B	110.9
C6—C7—H7A	119.8	C10—C11—H11B	110.9
C7—C8—C8A	120.9 (2)	H11A—C11—H11B	108.9

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C7—H7A···N1^i	0.93	2.61	3.464 (4)	153

Symmetry code: (i) −y+1, x−y, z.