6-Eth­oxy­carbonyl-5,7-dihy­droxy-2,3-dihydro-1H-pyrido[3,2,1-ij]quinolinium tribromide

Victor B Rybakov; Svitlana V Shishkina; Igor V Ukrainets; Nikolai Yu Golik; Igor N Chernenok

doi:10.1107/S1600536812049276

. 2012 Dec 15;69(Pt 1):o82. doi: 10.1107/S1600536812049276

6-Ethoxycarbonyl-5,7-dihydroxy-2,3-dihydro-1H-pyrido[3,2,1-ij]quinolinium tribromide

Victor B Rybakov ^a,^*, Svitlana V Shishkina ^b, Igor V Ukrainets ^c, Nikolai Yu Golik ^c, Igor N Chernenok ^c

PMCID: PMC3588293 PMID: 23476464

Abstract

In the title salt, C₁₅H₁₆NO₄ ^+.Br₃ ⁻, classical intramolecular O—H⋯O hydrogen bonds are found, which results in the co-planarity of the ester substituents with the quinolinium residue [C—C—C—O torsion angle = 1.0 (10)°]. The bromine anions are placed on both sides of heterocyclic cation and form Br⋯N contacts of 3.674 (9) and 3.860 (9) Å, which confirms the location of positive charge on the N atom. Non-classical intermolecular C—H⋯Br interactions stabilize the three-dimensional crystal structure. Moreover, anion⋯π interactions are noted [Br⋯ring centroid range = 3.367 (9)–3.697 (9) Å]. The partly saturated heterocycle is disordered over two sofa conformations with occupancies in the ratio 0.56 (2):0.44 (2).

Related literature

For general background, see: Ukrainets et al. (2004 ▶, 2007 ▶). For chemical bond lengths, see: Bürgi & Dunitz (1994 ▶).

Experimental

Crystal data

C₁₅H₁₆NO₄ ⁺·Br₃ ⁻
M _r = 513.99
Triclinic,
a = 7.6491 (8) Å
b = 9.1729 (10) Å
c = 13.3722 (14) Å
α = 102.355 (9)°
β = 98.777 (9)°
γ = 98.093 (9)°
V = 891.06 (17) Å³
Z = 2
Mo Kα radiation
μ = 6.81 mm⁻¹
T = 295 K
0.20 × 0.05 × 0.05 mm

Data collection

Agilent Xcalibur-3 CCD diffractometer
Absorption correction: multi-scan (CrysAlis RED; Agilent, 2011 ▶) T _min = 0.343, T _max = 0.727
10147 measured reflections
5106 independent reflections
1855 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.068
wR(F ²) = 0.217
S = 0.90
5106 reflections
224 parameters
5 restraints
H-atom parameters constrained
Δρ_max = 1.02 e Å⁻³
Δρ_min = −0.74 e Å⁻³

Data collection: CrysAlis CCD (Agilent, 2011 ▶); cell refinement: CrysAlis RED (Agilent, 2011 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Click here for additional data file.^{(29.3KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812049276/aa2080sup1.cif

e-69-00o82-sup1.cif^{(29.3KB, cif)}

Click here for additional data file.^{(250KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812049276/aa2080Isup2.hkl

e-69-00o82-Isup2.hkl^{(250KB, hkl)}

Click here for additional data file.^{(16.3KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812049276/aa2080Isup3.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
O2—H2⋯O4	0.82	1.93	2.631 (7)	142
O1—H1⋯O3	0.82	1.73	2.459 (10)	147
C3—H3⋯Br1ⁱ	0.93	2.90	3.810 (9)	168
C4—H4⋯Br2ⁱⁱ	0.93	3.06	3.846 (9)	143
C10—H10B⋯Br2	0.97	2.99	3.936 (8)	166
C10—H10C⋯Br4ⁱⁱⁱ	0.97	2.92	3.752 (8)	144
C11A—H11B⋯Br4ⁱⁱⁱ	0.97	3.02	3.797 (17)	138

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

supplementary crystallographic information

Comment

Bromination of alkyl 1-R-4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylates (R = H, alkyl, phenyl) by molecular bromine in the environment of acetic acid can pass on two directions (Ukrainets et al., 2004, 2007). However, the reaction of ethyl 7-hydroxy-5-oxo-2,3-dihydro-1H,5H-pyrido[3,2,1-ij]quinoline-6-carboxylate with bromine results in the 6-ethyloxycarbonyl-5,7-dihydroxy-2,3-dihydro-1H-pyrido[3,2,1-ij]quinolinium tribromide, I.

Two tribromide anions are located in special positions, the coordinates of the central atoms coincide with the center of symmetry so the asymmetric part of unit cell contains one cation and two halves of anions. The positive charge of the cation is located on the N atom which is bonded with three atoms and the N1═C9 bond (1.335 (6) Å) has double character (the mean value for Csp²═N bond is 1.329 (1) Å (Bürgi & Dunitz, 1994)).

The partly saturated heterocycle is disordered over two sofa conformations (A and B) with population in the ratio 0.56 (2)/0.44 (2). The deviations of the C11 atom from main plane C1/C2/N1/C10/C12 are -0.57 (1) and 0.59 (1) Å for conformers A and B, respectively. The ester substituent is coplanar to the planar fragment of tricycle (C9—C8—C13—O3 torsion angle is 1.0 (10)°) owing to the formation of the strong intramolecular hydrogen bonds O1—H1···O3 and O2—H2···O4 (Table 1). The formation of hydrogen bonds causes the elongation of the C13═O3 (1.243 (10) Å) and C7═C8 (1.376 (9) Å) bonds (the mean values are 1.210 (1) Å and 1.326 (1) Å, respectively) and the shortening of the C9—O1 (1.307 (8) Å), C7—O2 (1.299 (8) Å) bonds (the mean value is 1.333 (1) Å). The methylene atom from ethyl group of the substituent has ap-orientation relative to the C8—C13 bond and is turned relative to the C13—O4 bond (the C14—O4—C13—C8 and C13—O4—C14—C15 torsion angles are 175.7 (6)° and -155.4 (8)°, respectively).

Experimental

A solution of anhydrous bromine (0.52 ml, 0.01 mol) in anhydrous acetic acid (5 ml) was added with vigorous stirring to a solution of the ethyl 7-hydroxy-5-oxo-2,3-dihydro-1H,5H-pyrido[3,2,1-ij]quinoline-6-carboxylate (2.73 g, 0.01 mol) in anhydrous acetic acid (20 ml). A light-yellow precipitate was formed immediately. The crystals of I were filtered off, washed with acetic acid and dried to give the product (2.26 g, 44%); m.p. 360–362 K.