3-(2-Eth­oxy-2-oxoeth­yl)-4,5,6,7,8,9-hexa­hydrocyclo­octa­[d][1,2,3]selena­diazol-3-ium bromide

Schollmeyer, D.; Detert, H.

doi:10.1107/S2414314625001439

organic compounds

IUCrDATA

ISSN: 2414-3146

Volume 10| Part 2| February 2025| x250143

https://doi.org/10.1107/S2414314625001439

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3-(2-Ethoxy-2-oxoethyl)-4,5,6,7,8,9-hexahydrocycloocta[d][1,2,3]selenadiazol-3-ium bromide

Dieter Schollmeyer ^a and Heiner Detert ^a ^*

^aUniversity of Mainz, Department of Chemistry, Duesbergweg 10-14, 55099 Mainz, Germany
^*Correspondence e-mail: detert@uni-mainz.de

Edited by M. Bolte, Goethe-Universität Frankfurt, Germany (Received 6 February 2025; accepted 17 February 2025; online 28 February 2025)

The title compound, C₁₂H₁₉N₂O₂Se⁺·Br⁻, features a selenadiazole five-membered ring attached to a cyclooctene ring. A bromine anion is located in the vicinity of the selenium atom [3.0197 (5) Å]

Keywords: crystal structure; selenium; heterocycle; medium-sized ring.

CCDC reference: 2424352

Structure description

1,2,3-Selenadiazoles are known as precursors for alkynes, especially strained cycloalkynes (Bissinger et al., 1988 ; Detert & Meier, 1997 ). Jaffari et al. (1970 ) reported benzo-annulated selenadiazolium salts, and the first 1,2,3-selenadiazolium salt was described by Butler & Fox (2001 ). Recently, N-methylated selenadiazoles were characterized by us (Schollmeyer & Detert, 2016 , 2017 ).

The molecular structure of the title compound (Fig. 1) is composed of a cyclooctene ring with a boat-twist conformation, a 1,2,3-selenadiazole ring, an ethylacetate unit, and a bromide anion in the vicinity of the selenium atom. The selenadiazole ring is planar with a maximum deviation of 0.018 (3) Å from the mean plane at N2 whereas N3 is slightly below the ring. In spite of the conformational freedom, the ester unit, C12–C17, is almost planar; here the maximum deviation from the mean plane is 0.117 (2) Å at O15. These planes subtend a dihedral angle of 77.24 (14)°. The cyclooctene ring adopts a distorted boat-chair conformation (Evans & Boeyens, 1988 ). The bromide ion is located in the vicinity of the selenium atom [3.0197 (5) Å], opposite to the carbonyl group and slightly below the selenadiazole plane [0.5364 (3) Å]. The packing is shown in Fig. 2.

Figure 1
View (Macrae et al., 2020

) of the title compound. Displacement ellipsoids are drawn at the 50% probability level.

Figure 2
Part of the packing diagram. View along a-axis direction (Spek, 2020

Synthesis and crystallization

The title compound was prepared by adding ethyl bromoacetate (2.5 ml) to a solution of cycloocteno-1,2,3-selenadiazole (0.9 g, 4 mmol) (Meier & Voigt, 1972 ) in nitromethane (12 ml). The mixture was kept for one month at room temperature under exclusion of light. Two isomeric selenadiazolium salts in a 2.5:1 ratio were formed (¹H-NMR), the main isomer was isolated by evaporation of the solvent and chromatography on silica gel using chloroform/propanol-2 as eluent. Yield: 0.65 g of the pure title compound (43%), m.p.: 435 K. IR (KBr): 2975, 2912, 2855, 1733, 1711, 1522, 1472, 1447, 1368, 1339, 1240, 1220, 1022 cm⁻¹.¹H-NMR (CDCl₃, 400 MHz): 5.63 (s, 2 H, N—CH₂; ¹³C-satellites, J = 148 Hz), 4.26, (q, J = 7.5 Hz, OCH₂), 3.75 (pseudo-t, 2 H, 10-CH₂), 3.17 (pseudo-t, 2 H, 5-CH₂), 1.90 (qui, 2 H, 9-CH₂), 1.78 (qui, 2 H, 6-CH₂), 1.40 (m, 4 H, CH₂), 1.26 ppm (t, 3 H, CH₃). NOE: Irradiation into 5.63: positive NOE at 3.17, 1.78 ppm. 175.6 (C11, Se-satellites, ¹J_C–Se = 160 Hz), 164.0 (C=O), 154.4 (C-4) 64.4 (OCH₂), 61.0 (NCH₂), 31.2 (C-9), 30.5 (C-10), 28.2 (C-6), 26.8 (C-5), 25.6 (C-7), 24.8 (C-7), 13.9 (CH₃) ppm. Numbering of atoms according to scheme 1. MS: (EI): 685 (19%, Se₂Br-isotope pattern), (C₁₂H₁₉O₂N₂Se)₂Br⁺); 381 (4%, M+).

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 1.

Table 1
Experimental details

Crystal data
Chemical formula	C₁₂H₁₉N₂O₂Se⁺·Br⁻
M_r	382.16
Crystal system, space group	Triclinic, P $[\overline{1}]$
Temperature (K)	120
a, b, c (Å)	8.4924 (7), 9.3927 (7), 9.7799 (8)
α, β, γ (°)	71.379 (6), 86.439 (7), 74.119 (6)
V (Å³)	710.78 (10)
Z	2
Radiation type	Mo Kα
μ (mm⁻¹)	5.45
Crystal size (mm)	0.37 × 0.35 × 0.18

Data collection
Diffractometer	Stoe IPDS 2T
Absorption correction	Integration [X-RED32 (Stoe, & Cie, 2020 ), absorption correction by Gaussian integration, analogous to Coppens (1970 )]
T_min, T_max	0.163, 0.405
No. of measured, independent and observed [I > 2σ(I)] reflections	6548, 3370, 3085
R_int	0.030
(sin θ/λ)_max (Å⁻¹)	0.659

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.035, 0.096, 1.10
No. of reflections	3370
No. of parameters	164
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	1.39, −0.84
Computer programs: X-AREA WinXpose, Recipe, Integrate (Stoe & Cie, 2020), SHELXT2014 (Sheldrick, 2015a ), SHELXL2019/3 (Sheldrick, 2015b ), PLATON (Spek, 2020 ) and Mercury (Macrae et al., 2020 ).

Structural data

CCDC reference: 2424352

Crystal structure: contains datablocks I, global. DOI: https://doi.org/10.1107/S2414314625001439/bt4164sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2414314625001439/bt4164Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2414314625001439/bt4164Isup3.cml

checkCIF report

Computing details top

3-(2-Ethoxy-2-oxoethyl)-4,5,6,7,8,9-hexahydrocycloocta[d][1,2,3]selenadiazol-3-ium bromide top

Crystal data top

C₁₂H₁₉N₂O₂Se⁺·Br⁻	F(000) = 380
M_r = 382.16	D_x = 1.786 Mg m⁻³
Triclinic, P1	Melting point: 435 K
a = 8.4924 (7) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.3927 (7) Å	Cell parameters from 10409 reflections
c = 9.7799 (8) Å	θ = 2.5–28.4°
α = 71.379 (6)°	µ = 5.45 mm⁻¹
β = 86.439 (7)°	T = 120 K
γ = 74.119 (6)°	Block, colorless
V = 710.78 (10) Å³	0.37 × 0.35 × 0.18 mm
Z = 2

Data collection top

Stoe IPDS 2T diffractometer	3370 independent reflections
Radiation source: sealed X-ray tube, 12x0.4mm long-fine focus	3085 reflections with I > 2σ(I)
Detector resolution: 6.67 pixels mm^-1	R_int = 0.030
rotation method, ω scans	θ_max = 27.9°, θ_min = 2.5°
Absorption correction: integration [X-Red32 (Stoe, & Cie, 2020), absorption correction by Gaussian integration, analogous to Coppens (1970)]	h = −9→11
T_min = 0.163, T_max = 0.405	k = −12→12
6548 measured reflections	l = −12→12

Refinement top

Refinement on F²	Primary atom site location: dual
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.035	H-atom parameters constrained
wR(F²) = 0.096	w = 1/[σ²(F_o²) + (0.0549P)² + 1.110P] where P = (F_o² + 2F_c²)/3
S = 1.10	(Δ/σ)_max = 0.001
3370 reflections	Δρ_max = 1.39 e Å⁻³
164 parameters	Δρ_min = −0.84 e Å⁻³
0 restraints

Special details top

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

Refinement. Hydrogen atoms were refined as riding on their parent atoms with C—H = 0.99 Å for methylene groups and with C—H = 0.98 Å for methyl groups. Isotropic displacement parameters of the H atoms were set to 1.2U_eq(C) or 1.5U_eq(C_methyl).

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
Br1	0.49934 (4)	0.22173 (3)	1.21107 (3)	0.02302 (10)
Se1	0.34890 (3)	0.21865 (3)	0.94061 (3)	0.01662 (10)
O14	0.1838 (3)	0.4488 (2)	0.4557 (2)	0.0206 (4)
O15	0.0967 (3)	0.2826 (2)	0.3758 (2)	0.0178 (4)
N2	0.2602 (3)	0.1785 (3)	0.7980 (3)	0.0173 (5)
N3	0.3497 (3)	0.2043 (3)	0.6843 (3)	0.0144 (4)
C4	0.4827 (3)	0.2615 (3)	0.6848 (3)	0.0143 (5)
C5	0.5890 (3)	0.2910 (3)	0.5563 (3)	0.0164 (5)
H5A	0.626019	0.384490	0.548184	0.020*
H5B	0.522922	0.313715	0.468181	0.020*
C6	0.7403 (4)	0.1532 (3)	0.5634 (3)	0.0187 (5)
H6A	0.704205	0.056317	0.590697	0.022*
H6B	0.785283	0.168197	0.465499	0.022*
C7	0.8790 (3)	0.1298 (3)	0.6690 (3)	0.0197 (6)
H7A	0.977802	0.055683	0.648121	0.024*
H7B	0.905037	0.230735	0.650026	0.024*
C8	0.8431 (4)	0.0691 (3)	0.8295 (3)	0.0191 (5)
H8A	0.940889	−0.013424	0.878496	0.023*
H8B	0.752247	0.019621	0.838569	0.023*
C9	0.7976 (3)	0.1894 (3)	0.9106 (3)	0.0187 (5)
H9A	0.893461	0.229792	0.911700	0.022*
H9B	0.776542	0.135081	1.012018	0.022*
C10	0.6482 (3)	0.3294 (3)	0.8502 (3)	0.0163 (5)
H10A	0.614406	0.385169	0.922162	0.020*
H10B	0.679218	0.402734	0.761909	0.020*
C11	0.5076 (3)	0.2798 (3)	0.8151 (3)	0.0139 (5)
C12	0.2965 (3)	0.1714 (3)	0.5601 (3)	0.0167 (5)
H12A	0.237092	0.089818	0.594280	0.020*
H12B	0.393413	0.131917	0.507588	0.020*
C13	0.1851 (3)	0.3189 (3)	0.4589 (3)	0.0161 (5)
C16	−0.0031 (4)	0.4150 (4)	0.2620 (4)	0.0263 (7)
H16A	0.064370	0.484369	0.207894	0.032*
H16B	−0.094754	0.476150	0.304881	0.032*
C17	−0.0676 (4)	0.3498 (4)	0.1638 (4)	0.0245 (6)
H17A	−0.131725	0.435342	0.084350	0.037*
H17B	−0.137472	0.284484	0.217717	0.037*
H17C	0.024140	0.286559	0.124624	0.037*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.02640 (17)	0.02727 (17)	0.01503 (16)	−0.00549 (12)	0.00133 (12)	−0.00775 (12)
Se1	0.01565 (15)	0.02022 (16)	0.01349 (16)	−0.00509 (11)	0.00309 (10)	−0.00490 (11)
O14	0.0246 (10)	0.0171 (9)	0.0214 (10)	−0.0071 (8)	−0.0009 (8)	−0.0062 (8)
O15	0.0195 (10)	0.0160 (9)	0.0174 (10)	−0.0055 (8)	−0.0041 (8)	−0.0030 (8)
N2	0.0151 (11)	0.0218 (11)	0.0152 (11)	−0.0053 (9)	0.0007 (9)	−0.0056 (9)
N3	0.0135 (10)	0.0147 (10)	0.0158 (11)	−0.0046 (8)	0.0007 (8)	−0.0050 (8)
C4	0.0124 (11)	0.0122 (11)	0.0166 (12)	−0.0033 (9)	0.0003 (9)	−0.0021 (9)
C5	0.0161 (12)	0.0181 (12)	0.0147 (13)	−0.0068 (10)	0.0014 (10)	−0.0032 (10)
C6	0.0173 (12)	0.0230 (13)	0.0172 (13)	−0.0063 (11)	0.0046 (10)	−0.0081 (11)
C7	0.0139 (12)	0.0205 (13)	0.0232 (15)	−0.0033 (10)	0.0026 (11)	−0.0062 (11)
C8	0.0179 (13)	0.0187 (13)	0.0173 (13)	−0.0028 (10)	−0.0016 (10)	−0.0027 (10)
C9	0.0163 (12)	0.0225 (13)	0.0173 (13)	−0.0046 (10)	−0.0031 (10)	−0.0060 (11)
C10	0.0178 (12)	0.0155 (12)	0.0169 (13)	−0.0060 (10)	−0.0007 (10)	−0.0053 (10)
C11	0.0149 (12)	0.0117 (11)	0.0138 (12)	−0.0025 (9)	0.0022 (9)	−0.0037 (9)
C12	0.0184 (13)	0.0168 (12)	0.0173 (13)	−0.0061 (10)	0.0002 (10)	−0.0074 (10)
C13	0.0170 (12)	0.0194 (12)	0.0145 (12)	−0.0088 (10)	0.0033 (10)	−0.0059 (10)
C16	0.0371 (17)	0.0187 (13)	0.0204 (15)	−0.0025 (12)	−0.0127 (13)	−0.0043 (11)
C17	0.0245 (15)	0.0270 (15)	0.0213 (15)	−0.0055 (12)	−0.0067 (12)	−0.0064 (12)

Geometric parameters (Å, º) top

Se1—N2	1.811 (3)	C8—C9	1.533 (4)
Se1—C11	1.850 (3)	C8—H8A	0.9900
O14—C13	1.208 (3)	C8—H8B	0.9900
O15—C13	1.316 (3)	C9—C10	1.541 (4)
O15—C16	1.469 (4)	C9—H9A	0.9900
N2—N3	1.303 (3)	C9—H9B	0.9900
N3—C4	1.378 (3)	C10—C11	1.490 (4)
N3—C12	1.470 (4)	C10—H10A	0.9900
C4—C11	1.375 (4)	C10—H10B	0.9900
C4—C5	1.498 (4)	C12—C13	1.523 (4)
C5—C6	1.541 (4)	C12—H12A	0.9900
C5—H5A	0.9900	C12—H12B	0.9900
C5—H5B	0.9900	C16—C17	1.491 (4)
C6—C7	1.538 (4)	C16—H16A	0.9900
C6—H6A	0.9900	C16—H16B	0.9900
C6—H6B	0.9900	C17—H17A	0.9800
C7—C8	1.532 (4)	C17—H17B	0.9800
C7—H7A	0.9900	C17—H17C	0.9800
C7—H7B	0.9900

N2—Se1—C11	89.04 (12)	C10—C9—H9A	108.2
C13—O15—C16	115.5 (2)	C8—C9—H9B	108.2
N3—N2—Se1	109.05 (18)	C10—C9—H9B	108.2
N2—N3—C4	120.2 (2)	H9A—C9—H9B	107.4
N2—N3—C12	115.6 (2)	C11—C10—C9	111.8 (2)
C4—N3—C12	124.2 (2)	C11—C10—H10A	109.3
C11—C4—N3	112.7 (2)	C9—C10—H10A	109.3
C11—C4—C5	125.8 (2)	C11—C10—H10B	109.3
N3—C4—C5	121.5 (2)	C9—C10—H10B	109.3
C4—C5—C6	113.5 (2)	H10A—C10—H10B	107.9
C4—C5—H5A	108.9	C4—C11—C10	124.5 (2)
C6—C5—H5A	108.9	C4—C11—Se1	109.0 (2)
C4—C5—H5B	108.9	C10—C11—Se1	126.3 (2)
C6—C5—H5B	108.9	N3—C12—C13	110.1 (2)
H5A—C5—H5B	107.7	N3—C12—H12A	109.6
C7—C6—C5	115.8 (2)	C13—C12—H12A	109.6
C7—C6—H6A	108.3	N3—C12—H12B	109.6
C5—C6—H6A	108.3	C13—C12—H12B	109.6
C7—C6—H6B	108.3	H12A—C12—H12B	108.2
C5—C6—H6B	108.3	O14—C13—O15	126.4 (3)
H6A—C6—H6B	107.4	O14—C13—C12	123.5 (3)
C8—C7—C6	115.6 (2)	O15—C13—C12	110.1 (2)
C8—C7—H7A	108.4	O15—C16—C17	107.3 (2)
C6—C7—H7A	108.4	O15—C16—H16A	110.3
C8—C7—H7B	108.4	C17—C16—H16A	110.3
C6—C7—H7B	108.4	O15—C16—H16B	110.3
H7A—C7—H7B	107.4	C17—C16—H16B	110.3
C7—C8—C9	116.7 (2)	H16A—C16—H16B	108.5
C7—C8—H8A	108.1	C16—C17—H17A	109.5
C9—C8—H8A	108.1	C16—C17—H17B	109.5
C7—C8—H8B	108.1	H17A—C17—H17B	109.5
C9—C8—H8B	108.1	C16—C17—H17C	109.5
H8A—C8—H8B	107.3	H17A—C17—H17C	109.5
C8—C9—C10	116.3 (2)	H17B—C17—H17C	109.5
C8—C9—H9A	108.2

C11—Se1—N2—N3	2.47 (19)	C5—C4—C11—C10	−1.3 (4)
Se1—N2—N3—C4	−3.2 (3)	N3—C4—C11—Se1	0.0 (3)
Se1—N2—N3—C12	177.90 (18)	C5—C4—C11—Se1	−177.0 (2)
N2—N3—C4—C11	2.2 (4)	C9—C10—C11—C4	−87.9 (3)
C12—N3—C4—C11	−179.0 (2)	C9—C10—C11—Se1	87.2 (3)
N2—N3—C4—C5	179.4 (2)	N2—Se1—C11—C4	−1.4 (2)
C12—N3—C4—C5	−1.8 (4)	N2—Se1—C11—C10	−177.1 (2)
C11—C4—C5—C6	82.8 (3)	N2—N3—C12—C13	93.4 (3)
N3—C4—C5—C6	−94.1 (3)	C4—N3—C12—C13	−85.5 (3)
C4—C5—C6—C7	−74.3 (3)	C16—O15—C13—O14	4.8 (4)
C5—C6—C7—C8	71.2 (3)	C16—O15—C13—C12	−173.6 (2)
C6—C7—C8—C9	−102.0 (3)	N3—C12—C13—O14	21.8 (4)
C7—C8—C9—C10	57.4 (3)	N3—C12—C13—O15	−159.8 (2)
C8—C9—C10—C11	45.7 (3)	C13—O15—C16—C17	169.4 (3)
N3—C4—C11—C10	175.8 (2)

References

Bissinger, H.-J., Detert, H. & Meier, H. (1988). Liebigs Ann. Chem. pp. 221–224. CrossRef Google Scholar
Butler, R. N. & Fox, A. (2001). J. Chem. Soc. Perkin Trans. 1, pp. 394–397. Web of Science CrossRef Google Scholar
Coppens, P. (1970). Crystallographic Computing, edited by F. R. Ahmed, S. R. Hall & C. P. Huber, pp. 255–270. Copenhagen: Munksgaard. Google Scholar
Detert, H. & Meier, H. (1997). Liebigs Ann. Recl, pp. 1557–1563. Google Scholar
Evans, D. G. & Boeyens, J. C. A. (1988). Acta Cryst. B44, 663–671. CrossRef CAS Web of Science IUCr Journals Google Scholar
Jaffari, G. A., Nunn, A. J. & Ralph, J. T. (1970). J. Chem. Soc. C, pp. 2060–2062. Google Scholar
Macrae, C. F., Sovago, I., Cottrell, S. J., Galek, P. T. A., McCabe, P., Pidcock, E., Platings, M., Shields, G. P., Stevens, J. S., Towler, M. & Wood, P. A. (2020). J. Appl. Cryst. 53, 226–235. Web of Science CrossRef CAS IUCr Journals Google Scholar
Meier, H. & Voigt, E. (1972). Tetrahedron, 28, 187–198. CrossRef CAS Web of Science Google Scholar
Schollmeyer, D. & Detert, H. (2016). IUCrData, 1, x161950. Google Scholar
Schollmeyer, D. & Detert, H. (2017). IUCrData, 2, x170167. Google Scholar
Sheldrick, G. M. (2015a). Acta Cryst. A71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2015b). Acta Cryst. C71, 3–8. Web of Science CrossRef IUCr Journals Google Scholar
Spek, A. L. (2020). Acta Cryst. E76, 1–11. Web of Science CrossRef IUCr Journals Google Scholar
Stoe & Cie (2020). X-RED and X-AREA. Stoe & Cie, Darmstadt, Germany. Google Scholar

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