3-(2-Acetamido­eth­yl)-1H-indol-5-yl 4-nitro­phenyl carbonate

Jan K Maurin; Anna Zawadzka; Iwona Łozińska; Zbigniew Czarnocki

doi:10.1107/S1600536812038238

. 2012 Sep 12;68(Pt 10):o2915. doi: 10.1107/S1600536812038238

3-(2-Acetamidoethyl)-1H-indol-5-yl 4-nitrophenyl carbonate

Jan K Maurin ^a,^b,^*, Anna Zawadzka ^c, Iwona Łozińska ^c, Zbigniew Czarnocki ^c

PMCID: PMC3470262 PMID: 23125706

Abstract

In the title molecule, C₁₉H₁₇N₃O₆, the indole ring system is essentially planar (r.m.s. deviation = 0.009 Å) and forms a dihedral angle of 31.96 (9)° with the nitro-substituted benzene ring. In the crystal, molecules are linked by pairs of N—H⋯O hydrogen bonds, forming inversion dimers which are connected by further N—H⋯O hydrogen bonds into a two-dimensional network parallel to (102).

Related literature

For background to and potential applications of the title compound, see: Freer & McKillop (1996 ▶); Um et al. (2006 ▶, 2008 ▶); Gray et al. (1977 ▶); Zawadzka et al. (2012 ▶).

Experimental

Crystal data

C₁₉H₁₇N₃O₆
M _r = 383.36
Monoclinic,
a = 12.3678 (3) Å
b = 5.0537 (1) Å
c = 29.1554 (6) Å
β = 92.071 (2)°
V = 1821.11 (7) Å³
Z = 4
Cu Kα radiation
μ = 0.89 mm⁻¹
T = 293 K
0.40 × 0.10 × 0.07 mm

Data collection

Oxford Diffraction Xcalibur Ruby diffractometer
Absorption correction: analytical (CrysAlis PRO; Oxford Diffraction, 2010 ▶) T _min = 0.802, T _max = 0.956
16657 measured reflections
3397 independent reflections
2413 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.138
S = 1.06
3397 reflections
260 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.22 e Å⁻³
Δρ_min = −0.18 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2010 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812038238/lh5522sup1.cif

e-68-o2915-sup1.cif^{(20.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812038238/lh5522Isup2.hkl

e-68-o2915-Isup2.hkl^{(166.6KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812038238/lh5522Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯O1ⁱ	0.87 (2)	2.01 (2)	2.882 (2)	177 (2)
N12—H12⋯O6ⁱⁱ	0.77 (3)	2.54 (3)	3.207 (3)	147 (3)

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Symmetry codes: (i) Inline graphic ; (ii) .

Acknowledgments

This work was in part supported by the National Science Center (grant 2011/03/B/ST5/01593).

supplementary crystallographic information

Comment

The title compound is one of the aromatic carbonates, which constitute an important class of esters which facilitate the synthesis of a carbamate bond in the nucleofilic substitution reaction of carbonate derivatives with amines (Freer & McKillop, 1996; Um et al., 2006;2008). It is also a derivative which has potential use in peptide synthesis (Gray et al., 1977). We have used the title compound in the synthesis of novel tacrine-melatonine heterodimers (Zawadzka, et al., 2012).

The title compound consists of three major planar fragments and a large flexible substituent having several degrees of freedom. The planar fragments are the p-nitrophenyl fragment, carbonate group and indole group. The r.m.s. deviations of in-plane atoms for the respective planes are 0.006, 0.009 and 0.009 Å, respectively. The carbonate group forms a dihedral angle of 80.54 (8)° with the nitro-substituted benzene ring and forms a dihedral angle of 73.23 (6)° with the indole ring system. The nitro group is slightly rotated from the plane of the attached benzene ring with a dihedral angle of 8.0 (4)°. In general the bond lengths and angles have expected values. The benzene ring may affected by anistropic displacement causing slightly shorter than expected bond lengths to be observed. In the crystal, molecules are linked by a pair of N—H···O hydrogen bonds to forms inversion dimers which are connected by further N—H···O hydrogen bonds to form a two-dimensional network parallel to (102) (Table 1 and Fig. 2).

Experimental

To a solution of N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]acetamide (0.9 g, 4 mmol) in N-methylomorfoline (0.92 ml, 8 mmol) 4-nitrophenyl chloroformate (1.61 g, 8 mmol) dissolved in 1 ml of tetrahydrofuran was added. The reaction mixture was stirred under argon for 1 h at room temperature. Evaporation of the solvents gave a residue that was purified by silica gel chromatography using a mixture of methylene chloride/methanol 95:5 as eluent to produce the title compound (0.92 g, 60%) as a yellow solid. Crystals suitable for X-ray analysis were obtained by slow evaporation of a solution of the title compound in a methylene chloride/methanol/diethyl ether mixture.