[1-(1-Adamantylamino)ethyl­idene]oxonium methane­sulfonate

Robert Vícha; Marek Nečas; Zuzana Kozubková; Milan Potáček

doi:10.1107/S1600536809017632

. 2009 May 20;65(Pt 6):o1307. doi: 10.1107/S1600536809017632

[1-(1-Adamantylamino)ethylidene]oxonium methanesulfonate

Robert Vícha ^a,^*, Marek Nečas ^b, Zuzana Kozubková ^a, Milan Potáček ^b

PMCID: PMC2969600 PMID: 21583164

Abstract

In the title salt, C₁₂H₂₀NO⁺·CH₃SO₃ ⁻, the [1-(1-adamantylamino)ethylidene]oxonium cations and methanesulfonate anions are linked into chains along the a axis via O—H⋯O and N—H⋯O hydrogen bonds. All non-H atoms of the acetamido group are essentially planar, with a maximum deviation of 0.0085 (12) Å. In comparison with related structures, the carbonyl C=O bond is slightly elongated [1.249 (2) Å], whereas the amide C—N bond is shortened [1.292 (2) Å].

Related literature

For previously published structures of N-(1-adamantyl)acetamide, see: Pröhl et al. (1997 ▶); Kashino et al. (1998 ▶); Mizoguchi et al. (1997 ▶). For the preparation of N-(1-adamantyl)acetamide, see: Bach et al. (1979 ▶, 1980 ▶); Gerzon et al. (1963 ▶); Stetter et al. (1959 ▶, 1960 ▶). For the biological activity of related adamantane derivatives, see: Davies et al. (1964 ▶); Aldrich et al. (1971 ▶).

Experimental

Crystal data

C₁₂H₂₀NO⁺·CH₃SO₃ ⁻
M _r = 289.38
Orthorhombic,
a = 12.9848 (7) Å
b = 11.2625 (6) Å
c = 19.0037 (10) Å
V = 2779.1 (3) Å³
Z = 8
Mo Kα radiation
μ = 0.24 mm⁻¹
T = 120 K
0.40 × 0.40 × 0.35 mm

Data collection

Kuma KM-4 CCD diffractometer
Absorption correction: multi-scan (Xcalibur; Oxford Diffraction, 2006 ▶) T _min = 0.824, T _max = 0.914
19453 measured reflections
2454 independent reflections
2000 reflections with I > 2σ(I)
R _int = 0.017

Refinement

R[F ² > 2σ(F ²)] = 0.034
wR(F ²) = 0.102
S = 1.09
2454 reflections
180 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.47 e Å⁻³

Data collection: Xcalibur (Oxford Diffraction, 2006 ▶); cell refinement: Xcalibur (Oxford Diffraction, 2006 ▶); data reduction: Xcalibur (Oxford Diffraction, 2006 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809017632/pk2161sup1.cif

e-65-o1307-sup1.cif^{(17.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809017632/pk2161Isup2.hkl

e-65-o1307-Isup2.hkl^{(120.7KB, hkl)}

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⋯O3ⁱ	0.87 (2)	1.98 (2)	2.838 (2)	170.1 (19)
O1—H2⋯O2	0.98 (2)	1.49 (2)	2.4632 (18)	173 (2)

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Symmetry code: (i) Inline graphic .

Acknowledgments

The financial support of this work by the Czech Ministry of Education (project No. MSM 7088352101) is gratefully acknowledged.

supplementary crystallographic information

Comment

Since 1964, 1-aminoadamantane and related compounds have seen extensive examination due to their antiviral activity (Davies et al., 1964; Aldrich et al., 1971). The consecution of adamantane bromination, reaction with acetonitrile and final hydrolysis of N-(1-adamantyl)acetamide provides a viable synthetic method for 1-aminoadamantane production. The synthesis of N-(1-adamantyl)acetamide via nucleophilic substitution from varied bridgehead-substituted derivatives was previously described. For this purpose 1-iodoadamantane (Bach et al., 1980), 1-bromoadamantane (Stetter et al., 1960), 1-chloroadamantane (Gerzon et al., 1963), 1-alkoxyadamantane (Bach et al., 1979; Bach et al., 1980) or adamantan-1-ol (Stetter et al., 1959) were used as starting material. The title salt was prepared by replacement of a good-leaving group in 1-adamantyl methanesulfonate with acetonitrile.

In the structure of title salt (Fig. 1), the O-protonated N-(1-adamantyl)acetamide and methansulfonate are linked alternately into chains parallel to the a axis via O1–H2···O2 and N1–H1···O3 hydrogen bonds (Table 1, Fig. 2). All non-hydrogen atoms of the acetamido group (C11, C12, N1, O1) and C1 lie in plane with the maximum deviation from the best plane being 0.0085 (12) Å for atom N1. The distance of the H1 and H2 from the best plane (C1, C11, C12, N1, O1) is 0.004 (19) and 0.11 (2) Å respectively. In comparison with previously published structures of N-(1-adamantyl)acetamide (Pröhl et al., 1997; Kashino et al., 1998 and Mizoguchi et al. , 1997), the length of N1–C11 is slightly shorter, being 1.292 (2) Å [published 1.323 (5)–1.345 (2) Å] and C11–O1 is slightly longer at 1.294 (2) Å [published 1.230 (5)–1.237 (4) Å]. This may be attributed to enhanced electron withdrawing effect of the protonated O1.

Experimental

1-Adamantyl methansulfonate (500 mg, 2.17 mmol) was stirred in 20 ml of dry acetonitrile at room temperature for 1 h. After this period, the solution was allowed to stand at room temperature for several days and growth of crystals was observed. The solid was filtered off with suction and mother liquor was evaporated to obtain a second crop of title compound as a colourless powder. The combined yield of the title salt was 583 mg (93%). ¹H NMR spectra were similar to those obtained for equimolar mixture of separately prepared N-(1-adamantyl)acetamide and methanesulfonic acid.