organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890
Volume 69| Part 10| October 2013| Pages o1526-o1527

Di­pentyl 2,6-di­amino­benzo[1,2-b:4,5-b′]di­furan-3,7-di­carboxyl­ate

aDipartimento di Ingegneria, Università di Napoli 'Parthenope', Centro Direzionale di Napoli, Isola C4, 80143 Napoli, Italy, bDipartimento di Scienze Chimiche, Università degli Studi di Napoli 'Federico II', Complesso di Monte S. Angelo, Via Cinthia, 80126 Napoli, Italy, and cIstituto di Biostrutture e Bioimmagini, CNR, Via Mezzocannone 16, 80134 Naples, Italy
*Correspondence e-mail: giuseppina.roviello@uniparthenope.it, angela.tuzi@unina.it

(Received 27 July 2013; accepted 5 September 2013; online 12 September 2013)

The title compound, C22H28N2O6, crystallizes with one half-mol­ecule in the independent unit, the mol­ecule being located on an inversion centre. The penthyl groups are in the all-trans conformation and an almost planar conformation of the whole mol­ecule is observed [maximum deviation from the least-squares plane through all non-H atoms is 0.0229 (17) Å for an N atom]. The amino groups are involved in intra- and inter­molecular hydrogen bonds. Intra­molecular hydrogen bonding involving the amino group and ester carbonyl helps to lock the syn conformation of the ester with respect to the amino group. In the crystal, N—H⋯O hydrogen bonding involving the amino group and the furan and ester carbonyl O atoms self-assembles the mol­ecules into a two-dimensional hydrogen-bonded network parallel to (010) that displays inter­digital packing sustained by alk­yl–alkyl inter­actions.

Related literature

For the synthesis and properties of amino­benzodi­furane derivatives, see: Caruso et al. (2009[Caruso, U., Panunzi, B., Roviello, G. N., Roviello, G., Tingoli, M. & Tuzi, A. (2009). C. R. Chim. 12, 622-634.]). For O- and N-rich aromatic heterocycles, see: Roviello et al. (2007[Roviello, A., Buono, A., Carella, A., Roviello, G., Cassinese, A., Barra, M. & Biasucci, M. (2007). J. Polym. Sci. Part A Polym. Chem. 45, 1758-1760.], 2012[Roviello, G. N., Roviello, G., Musumeci, D., Bucci, E. M. & Pedone, C. (2012). Amino Acids, 43, 1615-1623.]). For mol­ecules with optical and opto-electronical properties, see: Carella et al. (2012[Carella, A., Borbone, F., Roviello, A., Roviello, G., Tuzi, A., Kravinsky, A., Shikler, R., Cantele, G. & Ninno, D. (2012). Dyes Pigm. 95, 116-125.]); Centore et al. (2007[Centore, R., Riccio, P., Fusco, S., Carella, A., Quatela, A., Schutzmann, S., Stella, F. & De Matteis, F. (2007). J. Polym. Sci. Part A Polym. Chem. 45, 2719-2725.]); Roviello et al. (2009[Roviello, A., Borbone, F., Carella, A., Diana, R., Roviello, G., Panunzi, B., Ambrosio, A. & Maddalena, P. (2009). J. Polym. Sci. Part A Polym. Chem. 47, 2677-2689.]); Ricciotti et al. (2013[Ricciotti, L., Borbone, F., Carella, A., Centore, R., Roviello, A., Barra, M., Roviello, G., Ferone, C., Minarini, C. & Morvillo, P. (2013). J. Polym. Sci. Part A Polym. Chem. doi:10.1002/pola.26849.]); Vitaliano et al. (2009[Vitaliano, R., Fratoddi, I., Venditti, I., Roviello, G., Battocchio, C., Polzonetti, G. & Russo, M. V. (2009). J. Phys. Chem. A, 113, 14730-14740.]). For hydrogen bonding in heterocycles, see: Centore et al. (2013a[Centore, R., Piccialli, V. & Tuzi, A. (2013a). Acta Cryst. E69, o667-o668.],b[Centore, R., Piccialli, V. & Tuzi, A. (2013b). Acta Cryst. E69, o802-o803.]).

[Scheme 1]

Experimental

Crystal data
  • C22H28N2O6

  • Mr = 416.46

  • Monoclinic, P 21 /c

  • a = 8.267 (1) Å

  • b = 7.994 (1) Å

  • c = 17.582 (3) Å

  • β = 98.98 (2)°

  • V = 1147.7 (3) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 0.09 mm−1

  • T = 173 K

  • 0.50 × 0.04 × 0.01 mm

Data collection
  • Bruker–Nonius KappaCCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2001[Bruker (2001). SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.957, Tmax = 0.999

  • 11093 measured reflections

  • 2626 independent reflections

  • 1258 reflections with I > 2σ(I)

  • Rint = 0.096

Refinement
  • R[F2 > 2σ(F2)] = 0.055

  • wR(F2) = 0.134

  • S = 0.93

  • 2626 reflections

  • 142 parameters

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.19 e Å−3

  • Δρmin = −0.20 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1A⋯O2i 0.83 (2) 2.11 (2) 2.935 (3) 171 (2)
N1—H1B⋯O1ii 0.84 (2) 2.34 (2) 3.066 (2) 144 (2)
N1—H1B⋯O2 0.84 (2) 2.41 (2) 2.942 (3) 122.2 (18)
Symmetry codes: (i) [-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) [-x+1, y-{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: COLLECT (Nonius, 1999[Nonius, B. V. (1999). COLLECT. Nonius BV, Delft, The Netherlands.]); cell refinement: DIRAX/LSQ (Duisenberg et al., 2000[Duisenberg, A. J. M., Hooft, R. W. W., Schreurs, A. M. M. & Kroon, J. (2000). J. Appl. Cryst. 33, 893-898.]); data reduction: EVALCCD (Duisenberg et al., 2003[Duisenberg, A. J. M., Kroon-Batenburg, L. M. J. & Schreurs, A. M. M. (2003). J. Appl. Cryst. 36, 220-229.]); program(s) used to solve structure: SIR97 (Altomare et al., 1999[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.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]) and Mercury (Macrae et al., 2006[Macrae, C. F., Edgington, P. R., McCabe, P., Pidcock, E., Shields, G. P., Taylor, R., Towler, M. & van de Streek, J. (2006). J. Appl. Cryst. 39, 453-457.]); software used to prepare material for publication: WinGX (Farrugia, 2012[Farrugia, L. J. (2012). J. Appl. Cryst. 45, 849-854.]).

Supporting information


Comment top

In the field of our studies on the synthesis and properties of aminobenzodifurane derivatives (Caruso et al. 2009) we prepared the title compound, C22H28N2O6. The presence of an aromatic heterocyclic core in the molecule makes this kind of compound interesting in organic electronics (Carella et al. 2012; Centore et al. 2007). 2,6-diamino-benzo[1,2 - b;4,5 - b']difuran-3,7-dicarboxylic acid (Fig. 1) crystallizes in P21/c space group with one half molecule in the independent unit. The molecule is located on a crystallographic inversion center and exhibits an all planar shape (maximum deviation from least square plane of the molecule is -0.0229 (17) for N1). The planarity of the molecule is a consequence of the all-trans conformation of penthyl groups and of the torsion angle at C6–O3 bond (C4—C6—O3—C7 = 179.7 (2)°). The planar conformation is also stabilized by intramolecular N—H···O=C hydrogen bonds (Table 1). In fact, the intramolecular hydrogen bonding involving the amino group and ester carbonyl helps to lock the syn conformation of ester with respect to amino group. The amino NH2 group is also involved in intermolecular hydrogen bonds, acting as donor towards benzodifurane oxigen (O1) and ester carbonyl oxygen (O2) acceptors (see Table 1). In the crystal packing (Fig. 2), molecules self-assemble into a two-dimensional hydrogen bonded network that display interdigital packing sustained by alkyl-alkyl interactions.

Related literature top

For the synthesis and properties of aminobenzodifurane derivatives, see: Caruso et al. (2009). For O- and N-rich aromatic heterocycles, see: Roviello et al. (2007, 2012). For molecules with optical and opto-electronical properties, see: Carella et al. (2012); Centore et al. (2007); Roviello et al. (2009); Ricciotti et al. (2013); Vitaliano et al. (2009). For hydrogen bonding in heterocycles, see: Centore et al. (2013a,b).

Experimental top

2,6-diamino-benzo[1,2 - b;4,5 - b']difuran-3,7-dicarboxylic acid was prepared according to the procedure described in the literature (Caruso et al. 2009). Crystals suitable for X-ray analysis were obtained by slow evaporation of dioxane/water solution.

Refinement top

All NH hydrogen atoms were located in difference Fourier maps and refined with Uiso=1.2Ueq(N) of the carrier atom. All the other H atoms were generated stereochemically and refined by the riding model with Uiso=1.2×Ueq of the carrier atom (1.5 for H atoms of the methyl groups).

Computing details top

Data collection: COLLECT (Nonius, 1999); cell refinement: DIRAX/LSQ (Duisenberg et al., 2000); data reduction: EVALCCD (Duisenberg et al., 2003); 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, 2012) and Mercury (Macrae et al., 2006); software used to prepare material for publication: WinGX (Farrugia, 2012).

Figures top
[Figure 1] Fig. 1. ORTEP view of the title compound. Thermal ellipsoids are drawn at 30% probability level.
[Figure 2] Fig. 2. Crystal packing viewed along b axis. Hydrogen bonds are drawn as dashed lines.
Dipentyl 2,6-diaminobenzo[1,2-b:4,5-b']difuran-3,7-dicarboxylate top
Crystal data top
C22H28N2O6F(000) = 444
Mr = 416.46Dx = 1.205 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 75 reflections
a = 8.267 (1) Åθ = 3.1–16.9°
b = 7.994 (1) ŵ = 0.09 mm1
c = 17.582 (3) ÅT = 173 K
β = 98.98 (2)°Block, grey
V = 1147.7 (3) Å30.50 × 0.04 × 0.01 mm
Z = 2
Data collection top
Bruker–Nonius KappaCCD
diffractometer
2626 independent reflections
Radiation source: normal-focus sealed tube1258 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.096
Detector resolution: 9 pixels mm-1θmax = 27.5°, θmin = 3.2°
CCD rotation images, thick slices scansh = 1010
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
k = 109
Tmin = 0.957, Tmax = 0.999l = 2222
11093 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.055Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.134H atoms treated by a mixture of independent and constrained refinement
S = 0.93 w = 1/[σ2(Fo2) + (0.061P)2]
where P = (Fo2 + 2Fc2)/3
2626 reflections(Δ/σ)max < 0.001
142 parametersΔρmax = 0.19 e Å3
0 restraintsΔρmin = 0.20 e Å3
Crystal data top
C22H28N2O6V = 1147.7 (3) Å3
Mr = 416.46Z = 2
Monoclinic, P21/cMo Kα radiation
a = 8.267 (1) ŵ = 0.09 mm1
b = 7.994 (1) ÅT = 173 K
c = 17.582 (3) Å0.50 × 0.04 × 0.01 mm
β = 98.98 (2)°
Data collection top
Bruker–Nonius KappaCCD
diffractometer
2626 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
1258 reflections with I > 2σ(I)
Tmin = 0.957, Tmax = 0.999Rint = 0.096
11093 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0550 restraints
wR(F2) = 0.134H atoms treated by a mixture of independent and constrained refinement
S = 0.93Δρmax = 0.19 e Å3
2626 reflectionsΔρmin = 0.20 e Å3
142 parameters
Special details top

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 (Å2) top
xyzUiso*/Ueq
C10.5923 (2)0.1341 (3)0.04464 (11)0.0257 (5)
H10.65560.23140.07310.026*
C20.5354 (2)0.0094 (3)0.07682 (11)0.0246 (5)
C30.4461 (2)0.1426 (3)0.03695 (11)0.0255 (5)
C40.4171 (2)0.2648 (3)0.09645 (11)0.0254 (5)
C50.4884 (3)0.1957 (3)0.16650 (12)0.0282 (5)
C60.3356 (2)0.4269 (3)0.09113 (12)0.0288 (6)
C70.1878 (3)0.6355 (3)0.00858 (11)0.0326 (6)
H7A0.09350.63560.03700.033*
H7B0.26440.72500.03010.033*
C80.1290 (3)0.6679 (3)0.07634 (12)0.0340 (6)
H8A0.22420.67000.10430.034*
H8B0.05560.57600.09790.034*
C90.0363 (3)0.8366 (3)0.08811 (12)0.0382 (6)
H9A0.11010.92710.06540.038*
H9B0.05830.83310.05980.038*
C100.0261 (3)0.8793 (3)0.17302 (13)0.0472 (7)
H10A0.06780.88220.20170.047*
H10B0.10190.79040.19580.047*
C110.1155 (4)1.0494 (3)0.18205 (16)0.0632 (8)
H11A0.15391.07110.23670.063*
H11B0.20941.04670.15420.063*
H11C0.04001.13830.16090.063*
N10.4973 (3)0.2479 (3)0.23935 (11)0.0383 (6)
H1A0.550 (3)0.192 (3)0.2748 (12)0.038*
H1B0.454 (3)0.340 (3)0.2485 (12)0.038*
O10.56177 (16)0.04310 (18)0.15705 (7)0.0292 (4)
O20.32315 (19)0.51874 (18)0.14725 (8)0.0377 (4)
O30.27143 (17)0.47150 (17)0.01739 (8)0.0324 (4)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0243 (13)0.0246 (14)0.0275 (12)0.0019 (10)0.0017 (10)0.0028 (10)
C20.0267 (12)0.0283 (14)0.0184 (11)0.0051 (11)0.0018 (9)0.0001 (10)
C30.0225 (12)0.0268 (14)0.0271 (12)0.0040 (10)0.0039 (10)0.0032 (10)
C40.0263 (12)0.0216 (13)0.0271 (12)0.0021 (10)0.0009 (10)0.0009 (10)
C50.0289 (13)0.0252 (15)0.0303 (13)0.0008 (11)0.0039 (10)0.0012 (11)
C60.0260 (13)0.0305 (15)0.0286 (13)0.0076 (11)0.0001 (10)0.0006 (11)
C70.0304 (13)0.0269 (14)0.0400 (14)0.0019 (11)0.0041 (11)0.0014 (11)
C80.0282 (13)0.0345 (16)0.0385 (13)0.0024 (11)0.0029 (11)0.0043 (11)
C90.0292 (13)0.0355 (16)0.0487 (15)0.0032 (11)0.0025 (12)0.0065 (12)
C100.0432 (16)0.0499 (18)0.0483 (15)0.0056 (14)0.0068 (13)0.0135 (13)
C110.0620 (19)0.054 (2)0.073 (2)0.0181 (16)0.0085 (16)0.0242 (15)
N10.0530 (14)0.0320 (14)0.0268 (12)0.0109 (11)0.0033 (10)0.0022 (10)
O10.0350 (9)0.0296 (10)0.0224 (8)0.0013 (7)0.0025 (7)0.0006 (7)
O20.0489 (10)0.0313 (10)0.0307 (9)0.0033 (8)0.0003 (7)0.0075 (7)
O30.0373 (9)0.0293 (10)0.0289 (9)0.0043 (7)0.0001 (7)0.0010 (7)
Geometric parameters (Å, º) top
C1—C21.393 (3)C7—H7B0.9900
C1—C3i1.422 (3)C8—C91.549 (3)
C1—H11.0231C8—H8A0.9900
C2—C31.418 (3)C8—H8B0.9900
C2—O11.419 (2)C9—C101.540 (3)
C3—C1i1.422 (3)C9—H9A0.9900
C3—C41.477 (3)C9—H9B0.9900
C4—C51.394 (3)C10—C111.543 (3)
C4—C61.457 (3)C10—H10A0.9900
C5—N11.338 (3)C10—H10B0.9900
C5—O11.384 (2)C11—H11A0.9800
C6—O21.247 (2)C11—H11B0.9800
C6—O31.369 (2)C11—H11C0.9800
C7—O31.479 (2)N1—H1A0.83 (2)
C7—C81.518 (3)N1—H1B0.84 (2)
C7—H7A0.9900
C2—C1—C3i114.40 (18)C7—C8—H8B109.5
C2—C1—H1127.3C9—C8—H8B109.5
C3i—C1—H1118.3H8A—C8—H8B108.1
C1—C2—C3126.93 (18)C10—C9—C8114.01 (19)
C1—C2—O1123.44 (18)C10—C9—H9A108.8
C3—C2—O1109.63 (17)C8—C9—H9A108.8
C2—C3—C1i118.67 (18)C10—C9—H9B108.8
C2—C3—C4106.02 (17)C8—C9—H9B108.8
C1i—C3—C4135.31 (19)H9A—C9—H9B107.6
C5—C4—C6122.45 (19)C9—C10—C11112.2 (2)
C5—C4—C3105.72 (18)C9—C10—H10A109.2
C6—C4—C3131.82 (18)C11—C10—H10A109.2
N1—C5—O1115.50 (19)C9—C10—H10B109.2
N1—C5—C4132.4 (2)C11—C10—H10B109.2
O1—C5—C4112.08 (18)H10A—C10—H10B107.9
O2—C6—O3121.9 (2)C10—C11—H11A109.5
O2—C6—C4124.58 (19)C10—C11—H11B109.5
O3—C6—C4113.54 (18)H11A—C11—H11B109.5
O3—C7—C8109.05 (16)C10—C11—H11C109.5
O3—C7—H7A109.9H11A—C11—H11C109.5
C8—C7—H7A109.9H11B—C11—H11C109.5
O3—C7—H7B109.9C5—N1—H1A119.4 (15)
C8—C7—H7B109.9C5—N1—H1B119.5 (15)
H7A—C7—H7B108.3H1A—N1—H1B121 (2)
C7—C8—C9110.81 (18)C5—O1—C2106.54 (16)
C7—C8—H8A109.5C6—O3—C7115.84 (15)
C9—C8—H8A109.5
C3i—C1—C2—C30.1 (3)C5—C4—C6—O20.8 (3)
C3i—C1—C2—O1179.41 (17)C3—C4—C6—O2178.5 (2)
C1—C2—C3—C1i0.1 (3)C5—C4—C6—O3179.06 (18)
O1—C2—C3—C1i179.49 (16)C3—C4—C6—O31.6 (3)
C1—C2—C3—C4179.22 (19)O3—C7—C8—C9178.43 (16)
O1—C2—C3—C40.2 (2)C7—C8—C9—C10179.49 (19)
C2—C3—C4—C50.7 (2)C8—C9—C10—C11179.2 (2)
C1i—C3—C4—C5179.8 (2)N1—C5—O1—C2178.64 (17)
C2—C3—C4—C6178.7 (2)C4—C5—O1—C20.8 (2)
C1i—C3—C4—C60.4 (4)C1—C2—O1—C5179.79 (18)
C6—C4—C5—N12.1 (4)C3—C2—O1—C50.3 (2)
C3—C4—C5—N1178.4 (2)O2—C6—O3—C70.4 (3)
C6—C4—C5—O1178.55 (17)C4—C6—O3—C7179.72 (16)
C3—C4—C5—O10.9 (2)C8—C7—O3—C6178.24 (17)
Symmetry code: (i) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O2ii0.83 (2)2.11 (2)2.935 (3)171 (2)
N1—H1B···O1iii0.84 (2)2.34 (2)3.066 (2)144 (2)
N1—H1B···O20.84 (2)2.41 (2)2.942 (3)122.2 (18)
Symmetry codes: (ii) x+1, y+1/2, z+1/2; (iii) x+1, y1/2, z+1/2.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1A···O2i0.83 (2)2.11 (2)2.935 (3)171 (2)
N1—H1B···O1ii0.84 (2)2.34 (2)3.066 (2)144 (2)
N1—H1B···O20.84 (2)2.41 (2)2.942 (3)122.2 (18)
Symmetry codes: (i) x+1, y+1/2, z+1/2; (ii) x+1, y1/2, z+1/2.
 

Acknowledgements

The authors thank the Centro Inter­dipartimentale di Metodologie Chimico–Fisiche, Università degli Studi di Napoli "Federico II" for the X-ray facilities.

References

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Volume 69| Part 10| October 2013| Pages o1526-o1527
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