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ISSN: 2056-9890

3,3′-(Ethane-1,2-di­yl)bis­­(3,4-di­hydro-2H-1,3-benzoxazine)

aDepartamento de Química, Universidad Nacional de Colombia, Ciudad Universitaria, Bogotá, Colombia, and bInstitute of Physics ASCR, v.v.i., Na Slovance 2, 182 21 Praha 8, Czech Republic
*Correspondence e-mail: ariverau@unal.edu.co

(Received 9 December 2011; accepted 12 December 2011; online 17 December 2011)

The title compound, C18H20N2O2, was prepared by Mannich-type reaction of phenol, ethane-1,2-diamine and formaldehyde. The heterocyclic rings adopt half-chair conformations. The acyclic methyl­ene groups attached to the N atoms are in an axial position. In the crystal, weak C—H⋯O hydrogen bonds link the mol­ecules into dimers. These dimers are further connected via C—H⋯π contacts.

Related literature

For related structures see: Rivera et al. (2011[Rivera, A., Camacho, J., Ríos-Motta, J., Pojarová, M. & Dušek, M. (2011). Acta Cryst. E67, o2028.], 2010[Rivera, A., Rojas, J. J., Ríos-Motta, J., Dušek, M. & Fejfarová, K. (2010). Acta Cryst. E66, o1134.]). For the preparation of the title compound, see: Rivera et al. (1989[Rivera, A., Aguilar, Z., Clavijo, D. & Joseph-Nathan, P. (1989). Anal. Quim. 85, 9-10.]). For ring conformations, see Cremer & Pople (1975[Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.]). For weak hydrogen bonds, see: Desiraju & Steiner (1999[Desiraju, G. R. & Steiner, T. (1999). The Weak Hydrogen Bond. Oxford University Press.]).

[Scheme 1]

Experimental

Crystal data
  • C18H20N2O2

  • Mr = 296.4

  • Monoclinic, P 21

  • a = 10.868 (2) Å

  • b = 5.1693 (13) Å

  • c = 13.327 (3) Å

  • β = 102.623 (18)°

  • V = 730.6 (3) Å3

  • Z = 2

  • Cu Kα radiation

  • μ = 0.71 mm−1

  • T = 120 K

  • 0.97 × 0.10 × 0.04 mm

Data collection
  • Agilent Xcalibur diffractometer with an Atlas (Gemini ultra Cu) detector

  • Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2010[Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, England.]) Tmin = 0.77, Tmax = 1

  • 2799 measured reflections

  • 1341 independent reflections

  • 785 reflections with I > 3σ(I)

  • Rint = 0.079

Refinement
  • R[F2 > 2σ(F2)] = 0.067

  • wR(F2) = 0.171

  • S = 1.38

  • 1341 reflections

  • 199 parameters

  • H-atom parameters constrained

  • Δρmax = 0.28 e Å−3

  • Δρmin = −0.25 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

Cg4 is the centroid of the C12–C17 ring.

D—H⋯A D—H H⋯A DA D—H⋯A
C11—H11a⋯O2i 0.96 2.47 3.415 (10) 168
C11—H11bCg4ii 0.96 2.58 3.523 (10) 169
Symmetry codes: (i) [-x+2, y+{\script{1\over 2}}, -z+2]; (ii) x, y+1, z.

Data collection: CrysAlis PRO (Agilent, 2010[Agilent (2010). CrysAlis PRO. Agilent Technologies, Yarnton, England.]); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SIR2002 (Burla et al., 2003[Burla, M. C., Camalli, M., Carrozzini, B., Cascarano, G. L., Giacovazzo, C., Polidori, G. & Spagna, R. (2003). J. Appl. Cryst. 36, 1103.]); program(s) used to refine structure: JANA2006 (Petříček et al., 2006[Petříček, V., Dušek, M. & Palatinus, L. (2006). JANA2006. Institute of Physics, Praha, Czech Republic.]); molecular graphics: DIAMOND (Brandenburg & Putz, 2005[Brandenburg, K. & Putz, H. (2005). DIAMOND. Crystal Impact, Bonn, Germany.]); software used to prepare material for publication: JANA2006.

Supporting information


Comment top

We have recently reported the molecular structure of two 3,3'-(ethane-1,2-diyl)bis(6-substituted-3,4-dihydro-2H-1,3-benzoxazine). The substituents in position 6 were methyl and chlorine respectively (Rivera et al., 2011, 2010). Their crystal structures established the existence of an anomeric effect in N—C—O sequence in oxazine ring. In connection with our interest in anomeric effect in benzo-fused oxazine ring, we decided it was important to establish the effect of substituent at the aromatic ring in the N—C—O moiety. Thus, we obtained the title compound (I) which has no substituent in position 6.

The molecular structure of the title compound is illustrated in Fig. 1. Unlike the related structures, which crystallized in monoclinic space groups P21/n (Rivera et al., 2011) and C2/c (Rivera et al., 2010) utilizing the crystallography inversion center in the molecular symmetry, the title compound (I) crystallizes in the polar space group P21 with one molecule in the asymmetric unit. The molecules of (I) thus have no internal symmetry. The fused six-membered heterocyclic rings exists in the approximate half-chair conformations with puckering parameters Q = 0.479 (9) Å, θ = 49.2 (11)° and ϕ = 94.4 (13)° for O1/C2/N1/C9/C8/C3 and Q = 0.482 (8) Å, θ = 50.0 (10)° and ϕ = 101.1 (13)° for O2/C11/N2/C18/C17/C12 (Cremer & Pople, 1975). The C—O bond lengths [C2—O1, 1.451 (13) Å; C11—O2, 1.475 (11) Å] are longer than the values observed in related structure where the p-substituents in the aromatic rings is methyl [1.3755 (14) Å and 1.4525 (13) Å] (Rivera et al., 2011). However, in p-chlorine derivative, the C—O bond distance is significantlly longer from those in (I), [1.421 (2) Å and 1.529 (2) Å] (Rivera et al., 2010). The N1—C2 and N2—C11 bond lengths of 1.416 (9) Å and 1.431 (10) Å respectively, which are shorter than the expected bond length of 1.468 Å, provides structural evidence for the existence of an anomeric effect in both N—C—O groups.

In the crystal weak intermolecular C—H···O contacts (Table 1) that could be considered as weak hydrogen bonds (Desiraju & Steiner, 1999) link molecules into dimers (Fig. 2). Neighboring pair of these dimers are linked together via weaker C—H···π contacts into chains extended along the b axis (Figure 2).

Related literature top

For related structures see: Rivera et al. (2011, 2010). For the preparation of the title compound, see: Rivera et al. (1989). For ring conformations, see Cremer & Pople (1975). For weak hydrogen bonds, see: Desiraju & Steiner (1999).

Experimental top

To a stirred mixture of ethane-1,2-diamine (0.34 ml, 5 mmol) and phenol (0.94 g, 10 mmol) dissolved in dioxane (10 ml) was added dropwise an aqueous solution of formaldehyde (1.5 ml, 20 mmol). The reaction mixture was stirred for4 h. at room temperature. The resultant precipitate was collected, washed with water, dried in vacuum and recrystallized from ethanol to give title compound.

Refinement top

All H atoms atoms were positioned geometrically and treated as riding on their parent atoms. The isotropic atomic displacement parameters of hydrogen atoms were evaluated as 1.2×Ueq of the parent atom. As the structure contains only light atoms, the Friedel-pair reflections were merged and the Flack parameter has not been determined.

Computing details top

Data collection: CrysAlis PRO (Agilent, 2010); cell refinement: CrysAlis PRO (Agilent, 2010); data reduction: CrysAlis PRO (Agilent, 2010); program(s) used to solve structure: SIR2002 (Burla et al., 2003); program(s) used to refine structure: JANA2006 (Petříček et al., 2006); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: JANA2006 (Petříček et al., 2006).

Figures top
[Figure 1] Fig. 1. A view of (I) with the numbering scheme.displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. Packing of the molecules of the title compound view along b axis.
3,3'-(Ethane-1,2-diyl)bis(3,4-dihydro-2H-1,3-benzoxazine) top
Crystal data top
C18H20N2O2F(000) = 316
Mr = 296.4Dx = 1.347 Mg m3
Monoclinic, P21Cu Kα radiation, λ = 1.5418 Å
Hall symbol: P 2ybCell parameters from 1061 reflections
a = 10.868 (2) Åθ = 3.4–65.5°
b = 5.1693 (13) ŵ = 0.71 mm1
c = 13.327 (3) ÅT = 120 K
β = 102.623 (18)°Needle, colourless
V = 730.6 (3) Å30.97 × 0.10 × 0.04 mm
Z = 2
Data collection top
Agilent Xcalibur
diffractometer with an Atlas (Gemini ultra Cu) detector
1341 independent reflections
Radiation source: Enhance Ultra (Cu) X-ray Source785 reflections with I > 3σ(I)
Mirror monochromatorRint = 0.079
Detector resolution: 10.3784 pixels mm-1θmax = 65.7°, θmin = 3.4°
Rotation method data acquisition using ω scansh = 129
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2010)
k = 45
Tmin = 0.77, Tmax = 1l = 1515
2799 measured reflections
Refinement top
Refinement on F281 constraints
R[F2 > 2σ(F2)] = 0.067H-atom parameters constrained
wR(F2) = 0.171Weighting scheme based on measured s.u.'s w = 1/[σ2(I) + 0.0016I2]
S = 1.38(Δ/σ)max = 0.004
1341 reflectionsΔρmax = 0.28 e Å3
199 parametersΔρmin = 0.25 e Å3
0 restraints
Crystal data top
C18H20N2O2V = 730.6 (3) Å3
Mr = 296.4Z = 2
Monoclinic, P21Cu Kα radiation
a = 10.868 (2) ŵ = 0.71 mm1
b = 5.1693 (13) ÅT = 120 K
c = 13.327 (3) Å0.97 × 0.10 × 0.04 mm
β = 102.623 (18)°
Data collection top
Agilent Xcalibur
diffractometer with an Atlas (Gemini ultra Cu) detector
1341 independent reflections
Absorption correction: multi-scan
(CrysAlis PRO; Agilent, 2010)
785 reflections with I > 3σ(I)
Tmin = 0.77, Tmax = 1Rint = 0.079
2799 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0670 restraints
wR(F2) = 0.171H-atom parameters constrained
S = 1.38Δρmax = 0.28 e Å3
1341 reflectionsΔρmin = 0.25 e Å3
199 parameters
Special details top

Experimental. CrysAlisPro (Agilent, 2010) Empirical absorption correction using spherical harmonics, implemented in SCALE3 ABSPACK scaling algorithm.

Refinement. The refinement was carried out against all reflections. The conventional R-factor is always based on F. The goodness of fit as well as the weighted R-factor are based on F and F2 for refinement carried out on F and F2, respectively. The threshold expression is used only for calculating R-factors etc. and it is not relevant to the choice of reflections for refinement.

The program used for refinement, Jana2006, uses the weighting scheme based on the experimental expectations, see _refine_ls_weighting_details, that does not force S to be one. Therefore the values of S are usually larger than the ones from the SHELX program.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
C10.9998 (6)0.619 (2)0.7044 (5)0.038 (2)
N11.0853 (5)0.4006 (19)0.7006 (4)0.040 (2)
C21.2051 (7)0.420 (2)0.7681 (6)0.049 (3)
O11.2790 (5)0.6444 (18)0.7528 (4)0.0482 (19)
C31.2853 (7)0.677 (2)0.6506 (5)0.039 (3)
C41.3740 (7)0.854 (2)0.6314 (6)0.050 (3)
C51.3841 (7)0.898 (2)0.5301 (6)0.051 (3)
C61.3057 (7)0.766 (2)0.4522 (6)0.049 (3)
C71.2171 (7)0.595 (2)0.4717 (6)0.046 (3)
C81.2051 (7)0.549 (2)0.5724 (5)0.036 (2)
C91.1083 (7)0.361 (2)0.5963 (5)0.040 (3)
C100.9615 (6)0.630 (2)0.8071 (5)0.039 (2)
N20.8679 (5)0.8366 (19)0.8073 (4)0.036 (2)
C110.8763 (7)0.948 (2)0.9069 (5)0.039 (3)
O20.8508 (4)0.7615 (18)0.9838 (3)0.0389 (16)
C120.7491 (7)0.605 (2)0.9472 (5)0.036 (2)
C130.7116 (6)0.445 (2)1.0211 (5)0.037 (2)
C140.6127 (7)0.273 (2)0.9901 (6)0.043 (3)
C150.5531 (7)0.262 (2)0.8873 (5)0.039 (2)
C160.5905 (6)0.416 (2)0.8150 (5)0.040 (3)
C170.6897 (6)0.589 (2)0.8434 (5)0.033 (2)
C180.7386 (6)0.756 (2)0.7673 (5)0.035 (2)
H1a0.9259070.6019380.650190.0451*
H1b1.0408640.7778870.6934510.0451*
H2a1.2526590.2655850.7635060.0584*
H2b1.1952730.4167640.8379850.0584*
H41.4273960.945680.6871310.0595*
H51.4449941.0182640.51520.0611*
H61.3130090.7933750.3824690.0593*
H71.1630360.5059150.4157630.0546*
H9a1.0305940.3800270.5462770.0478*
H9b1.1368140.1868350.5901760.0478*
H10a0.9263860.4668410.8204540.0473*
H10b1.0346260.6622790.8607320.0473*
H11a0.9584271.0219810.9307140.0474*
H11b0.8187031.0904010.9017280.0474*
H130.7544370.4544561.0920730.0449*
H140.5857320.1637081.0393930.0519*
H150.4842530.1434710.8657630.0472*
H160.5474270.4031160.7441170.0481*
H18a0.7334880.6616760.704470.0422*
H18b0.6859450.9058480.7508860.0422*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.041 (4)0.046 (4)0.027 (3)0.005 (4)0.010 (3)0.005 (3)
N10.042 (3)0.041 (3)0.038 (4)0.008 (3)0.012 (3)0.002 (3)
C20.058 (5)0.053 (5)0.037 (4)0.011 (5)0.013 (4)0.010 (4)
O10.049 (3)0.064 (3)0.029 (3)0.002 (3)0.003 (2)0.004 (3)
C30.044 (5)0.044 (4)0.029 (4)0.002 (4)0.008 (3)0.001 (3)
C40.039 (4)0.050 (5)0.059 (6)0.001 (4)0.009 (4)0.017 (4)
C50.053 (5)0.035 (4)0.068 (6)0.005 (4)0.022 (4)0.006 (4)
C60.060 (5)0.040 (4)0.053 (5)0.003 (5)0.023 (4)0.004 (4)
C70.054 (5)0.040 (4)0.043 (4)0.002 (4)0.010 (4)0.001 (4)
C80.045 (4)0.034 (4)0.028 (4)0.004 (4)0.009 (3)0.002 (3)
C90.047 (5)0.035 (4)0.040 (4)0.002 (3)0.014 (3)0.004 (3)
C100.048 (4)0.044 (4)0.025 (4)0.006 (4)0.006 (3)0.003 (3)
N20.036 (3)0.041 (3)0.033 (4)0.003 (3)0.010 (3)0.002 (3)
C110.042 (4)0.034 (4)0.042 (4)0.003 (4)0.008 (3)0.004 (3)
O20.046 (3)0.036 (2)0.032 (3)0.008 (3)0.004 (2)0.001 (2)
C120.039 (4)0.033 (4)0.035 (4)0.000 (4)0.009 (3)0.001 (3)
C130.043 (4)0.046 (4)0.024 (4)0.003 (4)0.011 (3)0.003 (3)
C140.050 (5)0.041 (4)0.041 (4)0.001 (4)0.016 (3)0.004 (4)
C150.044 (4)0.035 (4)0.039 (4)0.004 (4)0.008 (3)0.001 (3)
C160.043 (4)0.042 (4)0.035 (4)0.004 (4)0.008 (3)0.004 (3)
C170.038 (4)0.039 (4)0.022 (3)0.003 (4)0.005 (3)0.007 (3)
C180.046 (4)0.030 (3)0.028 (4)0.008 (4)0.006 (3)0.006 (3)
Geometric parameters (Å, º) top
C1—N11.471 (13)C10—N21.474 (12)
C1—C101.516 (10)C10—H10a0.96
C1—H1a0.96C10—H10b0.96
C1—H1b0.96N2—C111.431 (10)
N1—C21.416 (9)N2—C181.450 (9)
N1—C91.480 (10)C11—O21.475 (11)
C2—O11.451 (13)C11—H11a0.96
C2—H2a0.96C11—H11b0.96
C2—H2b0.96O2—C121.370 (10)
O1—C31.388 (9)C12—C131.415 (12)
C3—C41.394 (13)C12—C171.395 (9)
C3—C81.373 (11)C13—C141.386 (12)
C4—C51.397 (12)C13—H130.96
C4—H40.96C14—C151.383 (9)
C5—C61.373 (12)C14—H140.96
C5—H50.96C15—C161.378 (12)
C6—C71.373 (13)C15—H150.96
C6—H60.96C16—C171.390 (12)
C7—C81.397 (11)C16—H160.96
C7—H70.96C17—C181.514 (12)
C8—C91.518 (13)C18—H18a0.96
C9—H9a0.96C18—H18b0.96
C9—H9b0.96
N1—C1—C10111.1 (7)C1—C10—N2110.8 (7)
N1—C1—H1a109.4711C1—C10—H10a109.4713
N1—C1—H1b109.4709C1—C10—H10b109.4708
C10—C1—H1a109.4717N2—C10—H10a109.4714
C10—C1—H1b109.4713N2—C10—H10b109.4714
H1a—C1—H1b107.7691H10a—C10—H10b108.1247
C1—N1—C2115.1 (8)C10—N2—C11112.8 (6)
C1—N1—C9112.2 (6)C10—N2—C18113.9 (8)
C2—N1—C9106.6 (6)C11—N2—C18108.4 (6)
N1—C2—O1115.3 (7)N2—C11—O2113.5 (8)
N1—C2—H2a109.4712N2—C11—H11a109.4711
N1—C2—H2b109.4708N2—C11—H11b109.4713
O1—C2—H2a109.4715O2—C11—H11a109.4716
O1—C2—H2b109.4712O2—C11—H11b109.4711
H2a—C2—H2b102.9256H11a—C11—H11b105.115
C2—O1—C3112.5 (7)C11—O2—C12113.3 (5)
O1—C3—C4116.4 (7)O2—C12—C13115.5 (6)
O1—C3—C8121.8 (8)O2—C12—C17123.5 (8)
C4—C3—C8121.8 (7)C13—C12—C17120.9 (8)
C3—C4—C5119.1 (8)C12—C13—C14119.4 (6)
C3—C4—H4120.4314C12—C13—H13120.2967
C5—C4—H4120.4309C14—C13—H13120.2963
C4—C5—C6119.0 (9)C13—C14—C15119.2 (8)
C4—C5—H5120.5111C13—C14—H14120.4096
C6—C5—H5120.5112C15—C14—H14120.4094
C5—C6—C7121.4 (8)C14—C15—C16121.5 (8)
C5—C6—H6119.2825C14—C15—H15119.2499
C7—C6—H6119.2824C16—C15—H15119.2504
C6—C7—C8120.5 (7)C15—C16—C17120.8 (6)
C6—C7—H7119.7553C15—C16—H16119.6195
C8—C7—H7119.7559C17—C16—H16119.6206
C3—C8—C7118.1 (8)C12—C17—C16118.3 (8)
C3—C8—C9120.3 (7)C12—C17—C18118.4 (7)
C7—C8—C9121.6 (7)C16—C17—C18123.4 (6)
N1—C9—C8112.0 (7)N2—C18—C17111.8 (5)
N1—C9—H9a109.4708N2—C18—H18a109.4715
N1—C9—H9b109.4706N2—C18—H18b109.4717
C8—C9—H9a109.4711C17—C18—H18a109.471
C8—C9—H9b109.4722C17—C18—H18b109.4706
H9a—C9—H9b106.8364H18a—C18—H18b107.0112
Hydrogen-bond geometry (Å, º) top
Cg4 is the centroid of the C12–C17 ring.
D—H···AD—HH···AD···AD—H···A
C11—H11a···O2i0.962.473.415 (10)168
C11—H11b···Cg4ii0.962.583.523 (10)169
Symmetry codes: (i) x+2, y+1/2, z+2; (ii) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC18H20N2O2
Mr296.4
Crystal system, space groupMonoclinic, P21
Temperature (K)120
a, b, c (Å)10.868 (2), 5.1693 (13), 13.327 (3)
β (°) 102.623 (18)
V3)730.6 (3)
Z2
Radiation typeCu Kα
µ (mm1)0.71
Crystal size (mm)0.97 × 0.10 × 0.04
Data collection
DiffractometerAgilent Xcalibur
diffractometer with an Atlas (Gemini ultra Cu) detector
Absorption correctionMulti-scan
(CrysAlis PRO; Agilent, 2010)
Tmin, Tmax0.77, 1
No. of measured, independent and
observed [I > 3σ(I)] reflections
2799, 1341, 785
Rint0.079
(sin θ/λ)max1)0.591
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.067, 0.171, 1.38
No. of reflections1341
No. of parameters199
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.28, 0.25

Computer programs: CrysAlis PRO (Agilent, 2010), SIR2002 (Burla et al., 2003), JANA2006 (Petříček et al., 2006), DIAMOND (Brandenburg & Putz, 2005).

Hydrogen-bond geometry (Å, º) top
Cg4 is the centroid of the C12–C17 ring.
D—H···AD—HH···AD···AD—H···A
C11—H11a···O2i0.962.473.415 (10)168.40
C11—H11b···Cg4ii0.962.583.523 (10)169
Symmetry codes: (i) x+2, y+1/2, z+2; (ii) x, y+1, z.
 

Acknowledgements

We acknowledge the Dirección de Investigaciones, Sede Bogotá (DIB) de la Universidad Nacional de Colombia, for financial support of this work, as well as the Institutional research plan No. AVOZ10100521 of the Institute of Physics and the Praemium Academiae project of the Academy of Sciences of the Czech Republic.

References

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First citationDesiraju, G. R. & Steiner, T. (1999). The Weak Hydrogen Bond. Oxford University Press.
First citationPetříček, V., Dušek, M. & Palatinus, L. (2006). JANA2006. Institute of Physics, Praha, Czech Republic.
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