2,9-Dimethyl-6H,13H-5:12,7:14-dimethano­dibenzo[d,i][1,3,6,8]tetraazecine

Rivera, A.; Maldonado, M.; Ríos-Motta, J.; González-Salas, D.; Dacunha-Marinho, B.

doi:10.1107/S1600536809038380

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 65| Part 10| October 2009| Page o2553

doi:10.1107/S1600536809038380

Open

access

2,9-Dimethyl-6H,13H-5:12,7:14-dimethanodibenzo[d,i][1,3,6,8]tetraazecine

Augusto Rivera,^a ^* Mauricio Maldonado,^a Jaime Ríos-Motta,^a Diego González-Salas ^a and Bruno Dacunha-Marinho ^b

^aDepartamento de Química, Universidad Nacional de Colombia, Bogotá, AA 14490, Colombia, and ^bEd. CACTUS, Campus Sur, Unidade de Raios X, Universidad de Santiago de Compostela, 15782, Spain
^*Correspondence e-mail: ariverau@unal.edu.co

(Received 12 August 2009; accepted 22 September 2009; online 26 September 2009)

In the title structure, C₁₈H₂₀N₄, the aromatic rings are almost orthogonal [81.6 (2)°]. The molecule has symmetry 2 since it is situated on a crystallographic twofold axis. There are only weak intermolecular interactions present in the structure, notably C—H⋯π-electron ring interactions. The ¹H and ¹³C NMR spectra are in accordance with the X-ray structure analysis.

Related literature

For the synthesis of the title compound, see: Volpp (1962 ); Kuznetsov et al. (2007 ). For related structures, see: Dickinson & Raymond (1923 ); Murray-Rust (1974 ); Murray-Rust & Ridell (1975 ); Murray-Rust & Smith (1975 ); Glister et al. (2005 ); Rivera et al. (2007 ); Volpp (1962). For the chemical reactivity of cyclic aminals, see: Rivera et al. (2005 ); Rivera & Maldonado (2006 ).

Experimental

Crystal data

C₁₈H₂₀N₄
M_r = 292.38
Orthorhombic, A b a 2
a = 9.9777 (3) Å
b = 18.8351 (4) Å
c = 7.6963 (2) Å
V = 1446.37 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 100 K
0.16 × 0.15 × 0.06 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2006 ) T_min = 0.872, T_max = 0.995
10245 measured reflections
807 independent reflections
737 reflections with I > 2σ(I)
R_int = 0.041

Refinement

R[F² > 2σ(F²)] = 0.033
wR(F²) = 0.090
S = 1.06
807 reflections
102 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Table 1
Geometry of C—H⋯ Cg interactions (Å,°)

Contact	C–H	C⋯Cg	H⋯Cg	C—H⋯Cg
C2–H2⋯Cgⁱ	0.95	3.509 (2)	2.68	147
C10–H10B⋯Cgⁱⁱ	0.98	3.559 (2)	2.61	163
Symmetry codes: (i) $[-x+{3\over2}, y, z+{1 \over 2}]$ ; (ii) $[-x+2, -y+{1\over2}, z-{1\over2}]$ . Cg denotes the centroid of the benzene ring C1–C6.

Data collection: APEX2 (Bruker, 2005 ); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809038380/fb2167sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809038380/fb2167Isup2.hkl

checkCIF report

Comment top

For many years, cyclic aminals (gem-diamine) have attracted intense attention because of their intriguing molecular structures, many of which have been determined by the X-ray crystallography (Murray-Rust, 1974; Murray-Rust & Ridell, 1975; Murray-Rust & Smith, 1975; Glister et al., 2005) and/or by ¹H- and ¹³C-NMR spectroscopy (Kuznetsov et al., 2007). In the course of the research of the reactivity of aminals we have synthesized crystals of the title compound that contains a cyclic aminal, i. e. 2,9-dimethyl-6H,13H-5:12,7:14-dimethanedibenzo [d,i][1,3,6,8]tetraazecine.

The title molecule is shown in Fig. 1. The planes through the symmetry-related aromatic rings are almost perpendicular: the interplanar angle through the atoms C1//C2//C3//C4//C5//C6 and its mentioned symmetry-related plane by (2-x,-y,z) is 81.6 (2)°.

There are only weak intermolecular interactions present in the structure, notably C-H···π-electron ring interactions (Tab. 1, Fig. 2).

Related literature top

For the synthesis of the title compound, see: Volpp (1962); Kuznetsov et al. (2007). For related structures, see: Dickinson & Raymond (1923); Murray-Rust (1974); Murray-Rust & Ridell (1975); Murray-Rust & Smith (1975); Glister et al. (2005); Rivera et al. (2007); Volpp (1962). For the chemical reactivity of cyclic aminals, see: Rivera et al. (2005); Rivera & Maldonado (2006).

Experimental top

A solution of 4-methyl-1,2-diaminebenzene (100 mg, 0.82 mmol) in water (8 ml) and methanol (2 ml) was added dropwise at 278 K to 5 ml of 37% aqueous formaldehyde while stirring it. The reaction mixture was removed from the cooling bath and allowed to warm to room temperature while still stirring it. After stirring at room temperature for 1 h the resultant precipitate was filtered off, washed with water, dried in vacuum and recrystallized from 2-propanol to give the title compound with 65% yield. The melting point of the title structure is 465 K. The melting point was determined visually using glass capillary tube with an Electrothermal melting point apparatus, model 9100, accuracy ±0.5 K, manufacturer: Electrothermal Thermo Scientific.

The NMR spectra were acquired at room temperature on a Bruker AMX 400 Advance spectrometer. ¹H NMR (δ, 399.9 MHz, CDCl₃): 2.33, 4.34, 6.92, 6.98. ¹³C NMR (δ, 100.0 MHz, CDCl₃): 21.0, 68.6, 126.1, 126.7, 136.2, 150.3, 153.2. m/z (EI): 292.2 (M⁺).

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

	Fig. 1. A view of the title molecule with the displacement ellipsoids shown at the 50% probability level with the atomic labelling scheme. The symmetry-related atoms by a crystallographic two-fold axis are indicated by "i".
	Fig. 2. C—H···π-electron arene intermolecular weak contacts in the title structure. The ring centroids are also depicted as red circles. [Symmetry code: (i) 3/2-x,y,1/2+z; (ii) 2-x,1/2-y,-1/2+z.]

2,9-Dimethyl-6H,13H-5:12,7:14- dimethanodibenzo[d,i][1,3,6,8]tetraazecine top

Crystal data top

C₁₈H₂₀N₄	D_x = 1.343 Mg m⁻³
M_r = 292.38	Melting point: 465 K
Orthorhombic, Aba2	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: A 2 -2ac	Cell parameters from 3533 reflections
a = 9.9777 (3) Å	θ = 3.0–26.1°
b = 18.8351 (4) Å	µ = 0.08 mm⁻¹
c = 7.6963 (2) Å	T = 100 K
V = 1446.37 (7) Å³	Prism, colourless
Z = 4	0.16 × 0.15 × 0.06 mm
F(000) = 624

Data collection top

Bruker APEXII CCD diffractometer	737 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.041
ω and ϕ scans	θ_max = 26.4°, θ_min = 2.2°
Absorption correction: multi-scan (SADABS; Sheldrick, 2006)	h = −12→12
T_min = 0.872, T_max = 0.995	k = −23→23
10245 measured reflections	l = −9→9
807 independent reflections

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.033	Hydrogen site location: difference Fourier map
wR(F²) = 0.090	H-atom parameters constrained
S = 1.06	w = 1/[σ²(F_o²) + (0.0593P)² + 0.5089P] where P = (F_o² + 2F_c²)/3
807 reflections	(Δ/σ)_max < 0.001
102 parameters	Δρ_max = 0.18 e Å⁻³
1 restraint	Δρ_min = −0.18 e Å⁻³
47 constraints

Crystal data top

C₁₈H₂₀N₄	V = 1446.37 (7) Å³
M_r = 292.38	Z = 4
Orthorhombic, Aba2	Mo Kα radiation
a = 9.9777 (3) Å	µ = 0.08 mm⁻¹
b = 18.8351 (4) Å	T = 100 K
c = 7.6963 (2) Å	0.16 × 0.15 × 0.06 mm

Data collection top

Bruker APEXII CCD diffractometer	807 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 2006)	737 reflections with I > 2σ(I)
T_min = 0.872, T_max = 0.995	R_int = 0.041
10245 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.033	1 restraint
wR(F²) = 0.090	H-atom parameters constrained
S = 1.06	Δρ_max = 0.18 e Å⁻³
807 reflections	Δρ_min = −0.18 e Å⁻³
102 parameters

Special details top

Experimental. The temperature was set with accuracy ±2 K.

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
C1	0.8848 (2)	0.09201 (10)	0.1159 (3)	0.0154 (5)
C2	0.7950 (2)	0.14289 (11)	0.1743 (3)	0.0179 (5)
H2	0.7273	0.1303	0.2555	0.021*
C3	0.8041 (2)	0.21256 (11)	0.1138 (3)	0.0189 (5)
H3	0.7407	0.2469	0.1516	0.023*
C4	0.9044 (2)	0.23234 (10)	−0.0007 (3)	0.0179 (5)
C5	0.9937 (2)	0.18036 (11)	−0.0609 (3)	0.0183 (5)
H5	1.0628	0.1932	−0.1398	0.022*
C6	0.9825 (2)	0.11024 (11)	−0.0067 (3)	0.0161 (5)
C7	1.0000	0.0000	−0.1714 (4)	0.0185 (7)
H7A	0.9337	0.0235	−0.2479	0.022*	0.50
H7B	1.0663	−0.0235	−0.2479	0.022*	0.50
C8	0.8318 (2)	−0.03101 (10)	0.0540 (3)	0.0173 (5)
H8A	0.7966	−0.0728	0.1173	0.021*
H8B	0.7556	−0.0095	−0.0093	0.021*
C9	1.0000	0.0000	0.2796 (4)	0.0157 (7)
H9A	0.9756	−0.0402	0.3562	0.019*	0.50
H9B	1.0244	0.0402	0.3562	0.019*	0.50
C10	0.9187 (2)	0.30907 (11)	−0.0569 (3)	0.0229 (5)
H10A	0.8308	0.3322	−0.0538	0.034*
H10B	0.9545	0.3109	−0.1754	0.034*
H10C	0.9800	0.3337	0.0221	0.034*
N1	1.07122 (18)	0.05643 (9)	−0.0750 (2)	0.0177 (4)
N2	0.87874 (17)	0.02065 (8)	0.1833 (2)	0.0155 (4)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0184 (10)	0.0147 (9)	0.0131 (10)	−0.0011 (7)	−0.0031 (9)	0.0001 (9)
C2	0.0181 (10)	0.0192 (10)	0.0163 (11)	−0.0007 (8)	−0.0019 (9)	−0.0009 (9)
C3	0.0212 (10)	0.0174 (9)	0.0179 (11)	0.0028 (8)	−0.0042 (9)	−0.0003 (9)
C4	0.0235 (11)	0.0157 (10)	0.0146 (10)	0.0019 (8)	−0.0050 (10)	−0.0007 (8)
C5	0.0228 (11)	0.0176 (9)	0.0145 (10)	−0.0032 (8)	−0.0006 (9)	0.0008 (9)
C6	0.0177 (10)	0.0171 (10)	0.0136 (10)	−0.0003 (8)	−0.0008 (9)	0.0003 (8)
C7	0.0250 (18)	0.0191 (15)	0.0115 (16)	0.0031 (13)	0.000	0.000
C8	0.0171 (10)	0.0164 (9)	0.0185 (11)	−0.0012 (8)	−0.0021 (9)	−0.0029 (9)
C9	0.0235 (18)	0.0126 (14)	0.0110 (17)	−0.0001 (12)	0.000	0.000
C10	0.0295 (12)	0.0169 (10)	0.0223 (12)	0.0004 (9)	0.0031 (10)	0.0023 (9)
N1	0.0213 (9)	0.0153 (8)	0.0166 (10)	0.0011 (7)	0.0018 (8)	0.0010 (7)
N2	0.0192 (9)	0.0127 (8)	0.0147 (9)	0.0002 (7)	−0.0005 (8)	0.0001 (7)

Geometric parameters (Å, º) top

C1—C2	1.386 (3)	C7—H7A	0.9900
C1—C6	1.399 (3)	C7—H7B	0.9900
C1—N2	1.442 (3)	C8—N1ⁱ	1.467 (3)
C2—C3	1.395 (3)	C8—N2	1.468 (3)
C2—H2	0.9500	C8—H8A	0.9900
C3—C4	1.385 (3)	C8—H8B	0.9900
C3—H3	0.9500	C9—N2	1.471 (2)
C4—C5	1.403 (3)	C9—N2ⁱ	1.471 (2)
C4—C10	1.515 (3)	C9—H9A	0.9900
C5—C6	1.390 (3)	C9—H9B	0.9900
C5—H5	0.9500	C10—H10A	0.9800
C6—N1	1.445 (3)	C10—H10B	0.9800
C7—N1ⁱ	1.478 (2)	C10—H10C	0.9800
C7—N1	1.478 (2)	N1—C8ⁱ	1.467 (3)

C2—C1—C6	119.92 (19)	N1ⁱ—C8—N2	117.66 (16)
C2—C1—N2	120.06 (19)	N1ⁱ—C8—H8A	107.9
C6—C1—N2	120.01 (18)	N2—C8—H8A	107.9
C1—C2—C3	120.0 (2)	N1ⁱ—C8—H8B	107.9
C1—C2—H2	120.0	N2—C8—H8B	107.9
C3—C2—H2	120.0	H8A—C8—H8B	107.2
C4—C3—C2	120.8 (2)	N2—C9—N2ⁱ	119.5 (3)
C4—C3—H3	119.6	N2—C9—H9A	107.4
C2—C3—H3	119.6	N2ⁱ—C9—H9A	107.4
C3—C4—C5	118.80 (19)	N2—C9—H9B	107.4
C3—C4—C10	120.40 (19)	N2ⁱ—C9—H9B	107.4
C5—C4—C10	120.8 (2)	H9A—C9—H9B	107.0
C6—C5—C4	120.8 (2)	C4—C10—H10A	109.5
C6—C5—H5	119.6	C4—C10—H10B	109.5
C4—C5—H5	119.6	H10A—C10—H10B	109.5
C5—C6—C1	119.49 (19)	C4—C10—H10C	109.5
C5—C6—N1	120.5 (2)	H10A—C10—H10C	109.5
C1—C6—N1	120.00 (18)	H10B—C10—H10C	109.5
N1ⁱ—C7—N1	119.8 (3)	C6—N1—C8ⁱ	112.77 (17)
N1ⁱ—C7—H7A	107.4	C6—N1—C7	113.10 (15)
N1—C7—H7A	107.4	C8ⁱ—N1—C7	114.98 (15)
N1ⁱ—C7—H7B	107.4	C1—N2—C8	112.79 (17)
N1—C7—H7B	107.4	C1—N2—C9	113.17 (14)
H7A—C7—H7B	106.9	C8—N2—C9	115.38 (15)

C6—C1—C2—C3	−1.4 (3)	C1—C6—N1—C8ⁱ	−70.2 (2)
N2—C1—C2—C3	177.63 (19)	C5—C6—N1—C7	−118.0 (2)
C1—C2—C3—C4	−1.9 (3)	C1—C6—N1—C7	62.4 (3)
C2—C3—C4—C5	2.7 (3)	N1ⁱ—C7—N1—C6	−77.89 (15)
C2—C3—C4—C10	−176.2 (2)	N1ⁱ—C7—N1—C8ⁱ	53.62 (14)
C3—C4—C5—C6	−0.2 (3)	C2—C1—N2—C8	110.4 (2)
C10—C4—C5—C6	178.7 (2)	C6—C1—N2—C8	−70.6 (2)
C4—C5—C6—C1	−3.1 (3)	C2—C1—N2—C9	−116.4 (2)
C4—C5—C6—N1	177.34 (19)	C6—C1—N2—C9	62.7 (3)
C2—C1—C6—C5	3.9 (3)	N1ⁱ—C8—N2—C1	79.7 (2)
N2—C1—C6—C5	−175.2 (2)	N1ⁱ—C8—N2—C9	−52.5 (3)
C2—C1—C6—N1	−176.53 (19)	N2ⁱ—C9—N2—C1	−78.27 (15)
N2—C1—C6—N1	4.4 (3)	N2ⁱ—C9—N2—C8	53.75 (14)
C5—C6—N1—C8ⁱ	109.4 (2)

Symmetry code: (i) −x+2, −y, z.

Experimental details

Crystal data
Chemical formula	C₁₈H₂₀N₄
M_r	292.38
Crystal system, space group	Orthorhombic, Aba2
Temperature (K)	100
a, b, c (Å)	9.9777 (3), 18.8351 (4), 7.6963 (2)
V (Å³)	1446.37 (7)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.16 × 0.15 × 0.06

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 2006)
T_min, T_max	0.872, 0.995
No. of measured, independent and observed [I > 2σ(I)] reflections	10245, 807, 737
R_int	0.041
(sin θ/λ)_max (Å⁻¹)	0.625

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.033, 0.090, 1.06
No. of reflections	807
No. of parameters	102
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.18, −0.18

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SIR97 (Altomare et al., 1999), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Geometry of C—H··· Cg interactions (Å,°). top

Cg denotes the centroid of the benzene ring (C1//C2//C3//C4//C5//C6).

Contact	C–H	C···Cg	H···Cg	C—H···Cg
C2–H2···Cgⁱ	0.95	3.509 (2)	2.68	147
C10–H10B···Cgⁱⁱ	0.98	3.559 (2)	2.61	163

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

Acknowledgements

Financial support of this research from the Division de Investigación sede Bogotá (DIB), and from the Departamento de Química, Universidad Nacional de Colombia, is gratefully acknowledged. DG-S thanks COLCIENCIAS for a fellowship.

References

Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115–119. Web of Science CrossRef CAS IUCr Journals Google Scholar
Bruker (2005). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Dickinson, R. C. & Raymond, A. L. (1923). J. Am. Chem. Soc. 45, 22–29. CrossRef CAS Google Scholar
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Glister, J. F., Vaughan, K., Biradha, K. & Zaworotko, M. J. (2005). J. Mol. Struct. 749, 78–83. Web of Science CSD CrossRef CAS Google Scholar
Kuznetsov, A. I., Shukkur, A. H. & Kamara, K. (2007). Russ. Chem. Bull. Int. Ed. 56, 563–565. Web of Science CrossRef CAS Google Scholar
Murray-Rust, P. (1974). J. Chem. Soc. Perkin Trans. 2, pp. 1136–1141. Google Scholar
Murray-Rust, P. & Ridell, F. G. (1975). Can. J. Chem. 53, 1933–1935. CrossRef CAS Web of Science Google Scholar
Murray-Rust, P. & Smith, I. (1975). Acta Cryst. B31, 587–589. CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
Rivera, A. & Maldonado, M. (2006). Tetrahedron Lett. 47, 7467–7471. Web of Science CrossRef CAS Google Scholar
Rivera, A., Ríos-Motta, J., Hernández-Barragán, A. & Joseph-Nathan, P. (2007). J. Mol. Struct. 831, 180–186. Web of Science CSD CrossRef CAS Google Scholar
Rivera, A., Ríos-Motta, J., Quevedo, R. & Joseph-Nathan, P. (2005). Rev. Colomb. Quim. 34, 105–115. CAS Google Scholar
Sheldrick, G. M. (2006). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Volpp, G. (1962). Chem. Ber. 95, 1493–1494. CrossRef CAS Web of Science Google Scholar