2-Hydr­oxy-3,3-dimethyl-7-nitro-3,4-dihydro­isoquinolin-1(2H)-one

Hassen Ben Salah; Majed Kammoun; Besma Hamdi; Luis Bohé; Mohamed Damak

doi:10.1107/S1600536808013457

. 2008 May 10;64(Pt 6):o1050. doi: 10.1107/S1600536808013457

2-Hydroxy-3,3-dimethyl-7-nitro-3,4-dihydroisoquinolin-1(2H)-one

Hassen Ben Salah ^a, Majed Kammoun ^a, Besma Hamdi ^b, Luis Bohé ^c, Mohamed Damak ^a,^*

PMCID: PMC2961355 PMID: 21202569

Abstract

In the title compound, C₁₁H₁₂N₂O₄, a new hydroxamic acid which belonging to the isoquinole family, the heterocyclic ring adopts a half-chair conformation. The nitro group is essentially coplanar with the aromatic ring. Intermolecular O—H⋯O hydrogen bonds assemble the molecules around inversion centres to form pseudo-dimers.

Related literature

For related literature, see: Bohé & Kammoun (2004 ▶); Kurzak et al. (1992 ▶); Porcheddu & Giacomelli (2006 ▶); Weber (1983 ▶); Miller (1989 ▶); Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₁₁H₁₂N₂O₄
M _r = 236.23
Monoclinic,
a = 5.8805 (9) Å
b = 18.605 (4) Å
c = 10.1588 (17) Å
β = 103.056 (12)°
V = 1082.7 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 296 K
0.60 × 0.51 × 0.22 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (Coppens et al., 1965 ▶) T _min = 0.938, T _max = 0.975
7659 measured reflections
3286 independent reflections
2051 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.150
S = 1.11
3286 reflections
157 parameters
H-atom parameters constrained
Δρ_max = 0.26 e Å⁻³
Δρ_min = −0.27 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1998 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶), ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2003 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536808013457/dn2332sup1.cif

e-64-o1050-sup1.cif^{(15.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808013457/dn2332Isup2.hkl

e-64-o1050-Isup2.hkl^{(196.4KB, 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
O12—H12⋯O11ⁱ	0.82	1.99	2.7013 (14)	144
O12—H12⋯O11	0.82	2.20	2.6305 (15)	113

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Symmetry code: (i) Inline graphic .

supplementary crystallographic information

Comment

Hydroxamic acids are strong metal ion chelators (Kurzak et al., 1992), they posses a wide spectrum of biological activities, such as antibacterial, antifungal, anti-inflammatory, and anti-asthmatic properties, etc. (Weber, 1983; Miller 1989).

The growing number of published synthetic methods further points to the biological significance of hydroxamic acids (Porcheddu & Giacomelli, 2006). Among this family of hydroxamic acids is the title compound (1). We report herein its synthesis and its crystal structure determination. Synthesis of the title compound has been prepared from the corresponding dihydroisoquinoleine (2) by metachloroperbenzoic acid oxidation (Fig. 1). Imine (2) was described by Bohé and Kammoun (2004), in three steps from the commercially available tertiary alcohol (3).

In the title compound, the heterocyclic ring adopts a half-chair conformation as indicated by the puckering parameters: Q = 0.4224 (14)Å, θ = 57.87 (18)°, φ = 281.2 (2)° (Cremer & Pople, 1975). The nitro group attached on C7 is essentially coplanar with the aromatic nucleus (Fig. 2). The methyl substituent in position 3 of the heterocyclic ring is pseudo-axial, the second methyl in position 3 is pseudo-equatorial.

The conformation of (1) is stabilized by an intramolecular hydrogen bond between the hydroxyl O12—H12 group and atom O11 (Table 1).The molecules are assembled by intermolecualr O-H···O hydrogen bonds to form pseudo dimer arranged around inversion centre (Table 1, Fig. 3)

Experimental

The title compound was prepared by reaction of imine (2) (100 mg, 0.49 mmol), and methachloroperbenzoique acid 86% (197 mg, 0.98 mmol) in dichloromethane (15 ml). The mixture was stirred at room temperature for 24 h. Then, the mixture was diluted with CH₂Cl₂ and washed with a solution of saturated NaHCO₃. The organic phase was dried over sodium sulfate, filtered and concentrated under reduced pressure. The concentrate was chromatographed on silica gel, with (ether) as eluent (yield 40%). m.p.418 K. Spectroscopic analysis, 1H NMR (300 MHz; DMSO-d₆, p.p.m): 1.26 (s, 6H, 2Me 3); 3.23 (s, 2H); 7.59 (d, J = 8.4, 1H, aromatic H); 8.33 (dd, J = 8.4, J= 2.4, 1H, aromatic H); 8.56 (d, J = 2.4, 1H aromatic H); 9.8 (s wide, 1H, OH). 13 C NMR (75 MHz; DMSO-d₆, p.p.m): 25.24; 41.80; 60.66; 122.02; 126.87; 129.91;130.41; 144.05; 147.21; 160.08. M.S (EI, 70 ev): m/z: 236 (M+.); 221 [(M–15)+., base peak]. MS (HR): Found: 236,0844 calcd mass for C₁₁H₁₂N₂O₄: 236,0875. Recrystallizations from dichloromethane afford yellow crystals suitable for diffraction.