2-[(E)-(3,4-Dimethyl­isoxazol-5-yl)imino­meth­yl]phenol

Fun, H.-K.; Hemamalini, M.; Asiri, A.M.; Khan, S.A.; Khan, K.A.

doi:10.1107/S1600536810008160

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 66| Part 4| April 2010| Pages o773-o774

doi:10.1107/S1600536810008160

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2-[(E)-(3,4-Dimethylisoxazol-5-yl)iminomethyl]phenol

Hoong-Kun Fun,^a ^*‡ Madhukar Hemamalini,^a Abdullah M. Asiri,^b § Salman A. Khan ^b and Khalid A. Khan ^b

^aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and ^bDepartment of Chemistry, Faculty of Science, King Abdu Aziz University, Jeddah, Saudi Arabia
^*Correspondence e-mail: hkfun@usm.my

(Received 24 February 2010; accepted 3 March 2010; online 6 March 2010)

The title compound, C₁₂H₁₂N₂O₂, has been synthesized by the reaction of 5-amino-3,4-dimethylisoxazole and salicyladehyde. The molecule adopts an E configuration about the central C=N double bond. The dihedral angle between the isoxazole and phenyl rings is 4.2 (2)° and an intramolecular O—H⋯N hydrogen bond generates an S(6) ring motif. The crystal studied was a non-merohedral twin with a domain ratio of 0.834 (4):0.166 (4).

Related literature

For background to the biological and pharmacological properties of oxazole derivatives, see: Spinelli (1999 ); Conti et al. (1998 ); Mishra et al. (1998 ); Ko et al. (1998 ); Kang et al. (2000 ); Huang & Chen (2005 ). For details of hydrogen bonding and hydrogen-bond motifs, see: Jeffrey & Saenger (1991 ); Bernstein et al. (1995 ); Jeffrey (1997 ); Scheiner (1997 ). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ).

Experimental

Crystal data

C₁₂H₁₂N₂O₂
M_r = 216.24
Triclinic, $[P \overline 1]$
a = 5.3475 (14) Å
b = 8.615 (2) Å
c = 12.321 (3) Å
α = 103.696 (5)°
β = 91.486 (5)°
γ = 94.059 (5)°
V = 549.6 (2) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 100 K
0.56 × 0.14 × 0.08 mm

Data collection

Bruker APEX DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ) T_min = 0.951, T_max = 0.993
2467 measured reflections
2467 independent reflections
1946 reflections with I > 2σ(I)

Refinement

R[F² > 2σ(F²)] = 0.070
wR(F²) = 0.203
S = 1.06
2467 reflections
152 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.40 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H1O2⋯N1	1.00 (9)	1.71 (8)	2.648 (5)	154 (8)

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810008160/sj2738sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810008160/sj2738Isup2.hkl

checkCIF report

Comment top

Heterocyclic compounds, especially isoxazoles, are one of the key building elements of natural products. Among the numerous heterocyclic systems of biological and pharmacological interest, the oxazole ring is endowed with various activities, including hypoglycemic (Spinelli, 1999), analgesic (Conti et al., 1998), anti-inflammatory (Mishra et al., 1998), anti-bacterial (Ko et al., 1998) and anti-tumor (Kang et al., 2000) properties. In view of the importance of the title compound as a pharmaceutical intermediate, the paper reports its synthesis and crystal structure.

In the title compound (Fig. 1), the isoxazole ring is essentially planar with a maximum deviation of 0.002 (2) Å for atom C8. The dihedral angle between the isoxazole ring (N2/O1/C8–C10) and the phenyl ring (C1–C6) is 4.30 (15)°. The methyl groups at C9 and C10 deviate from the isoxazole mean plane by 0.056 (3) Å and 0.013 (4) Å , respectively. The C5—O2 and C7═N1 bond lengths are 1.353 (4) Å and 1.293 (4) Å, respectively, and agree with the corresponding values in 4-{[(1E)-(3,5-dibromo-2-hydroxyphenyl) methylene]-amino}-1,5-dimethyl-2-phenyl-1,2-dihydro- 3H-pyrazol-3-one [1.344 (3) and 1.292 (4) Å; Huang & Chen, 2005].

In the crystal structure (Fig. 2), the imino N atoms are linked to the phenol O atoms and act as hydrogen-bond acceptors in intramolecular O2—H1O2···N1 interactions (Table 1) (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997), which generate S(6) ring motifs (Bernstein et al., 1995).

Related literature top

For background to the biological and pharmacological properties of oxazole derivatives, see: Spinelli (1999); Conti et al. (1998); Mishra et al. (1998); Ko et al. (1998); Kang et al. (2000); Huang & Chen (2005). For details of hydrogen bonding and hydrogen-bond motifs see: Jeffrey & Saenger (1991); Bernstein et al. (1995); Jeffrey (1997); Scheiner (1997). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

Experimental top

A mixture of 5-amino-3,4-dimethylisoxazole (0.50g, 0.0044 mol) and salicyladehyde (0.54g, 0.0044 mol) in methanol (15 mL) was refluxed for 5 h with stirring to give a light yellow precipitate. It was then filtered and washed with methanol to gives the pure Schiff base. Yield: 68%; mp. 116°C. IR (KBr) v_max cm^-1: 2922(C—H), 1594 (C═O), 1562 (C═C), 1152 (C—N). ¹H NMR (CDCl₃) d: 8.89 (s, 1H, CH olefinic), 7.42 (d, H3, J=1.8Hz), 7.44 (dd, H4, J=7.8Hz), 7.02 (dd, H5, J=7.8Hz), 6.97 (d, H6, J=1.2 Hz), 2.25 (s, CH3), 2.05 (s, CH3).

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The asymmetric unit of the title compound, showing 50% probability displacement ellipsoids and the atom-numbering scheme.
	Fig. 2. The crystal packing of the title compound (I).

2-[(E)-(3,4-Dimethylisoxazol-5-yl)iminomethyl]phenol top

Crystal data top

C₁₂H₁₂N₂O₂	Z = 2
M_r = 216.24	F(000) = 228
Triclinic, P1	D_x = 1.307 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 5.3475 (14) Å	Cell parameters from 2862 reflections
b = 8.615 (2) Å	θ = 2.4–29.7°
c = 12.321 (3) Å	µ = 0.09 mm⁻¹
α = 103.696 (5)°	T = 100 K
β = 91.486 (5)°	Plate, yellow
γ = 94.059 (5)°	0.56 × 0.14 × 0.08 mm
V = 549.6 (2) Å³

Data collection top

Bruker APEX DUO CCD area-detector diffractometer	2467 independent reflections
Radiation source: fine-focus sealed tube	1946 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.000
ϕ and ω scans	θ_max = 27.5°, θ_min = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −6→6
T_min = 0.951, T_max = 0.993	k = −11→10
2467 measured reflections	l = −6→15

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.070	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.203	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	w = 1/[σ²(F_o²) + (0.0657P)² + 1.1217P] where P = (F_o² + 2F_c²)/3
2467 reflections	(Δ/σ)_max = 0.001
152 parameters	Δρ_max = 0.40 e Å⁻³
0 restraints	Δρ_min = −0.34 e Å⁻³

Crystal data top

C₁₂H₁₂N₂O₂	γ = 94.059 (5)°
M_r = 216.24	V = 549.6 (2) Å³
Triclinic, P1	Z = 2
a = 5.3475 (14) Å	Mo Kα radiation
b = 8.615 (2) Å	µ = 0.09 mm⁻¹
c = 12.321 (3) Å	T = 100 K
α = 103.696 (5)°	0.56 × 0.14 × 0.08 mm
β = 91.486 (5)°

Data collection top

Bruker APEX DUO CCD area-detector diffractometer	2467 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2009)	1946 reflections with I > 2σ(I)
T_min = 0.951, T_max = 0.993	R_int = 0.000
2467 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.070	0 restraints
wR(F²) = 0.203	H atoms treated by a mixture of independent and constrained refinement
S = 1.06	Δρ_max = 0.40 e Å⁻³
2467 reflections	Δρ_min = −0.34 e Å⁻³
152 parameters

Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

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

	x	y	z	U_iso*/U_eq
O1	1.0387 (4)	1.1305 (2)	0.41739 (17)	0.0228 (5)
O2	0.6135 (4)	0.7350 (3)	0.08828 (18)	0.0262 (5)
N1	0.8330 (5)	0.9521 (3)	0.2591 (2)	0.0194 (5)
N2	1.2481 (5)	1.2478 (3)	0.4414 (2)	0.0252 (6)
C1	0.2930 (5)	0.7387 (3)	0.3499 (3)	0.0201 (6)
H1A	0.3082	0.7892	0.4256	0.024*
C2	0.0960 (5)	0.6240 (3)	0.3108 (3)	0.0221 (6)
H2A	−0.0224	0.5990	0.3593	0.026*
C3	0.0782 (6)	0.5468 (4)	0.1976 (3)	0.0249 (7)
H3A	−0.0529	0.4691	0.1710	0.030*
C4	0.2512 (6)	0.5831 (4)	0.1235 (3)	0.0250 (7)
H4A	0.2362	0.5296	0.0484	0.030*
C5	0.4491 (5)	0.7008 (3)	0.1626 (2)	0.0199 (6)
C6	0.4711 (5)	0.7802 (3)	0.2771 (2)	0.0186 (6)
C7	0.6723 (5)	0.9024 (3)	0.3225 (2)	0.0191 (6)
H7A	0.6859	0.9462	0.3992	0.023*
C8	1.0225 (5)	1.0682 (3)	0.3052 (2)	0.0176 (6)
C9	1.2091 (5)	1.1366 (3)	0.2539 (2)	0.0192 (6)
C10	1.3428 (5)	1.2479 (3)	0.3446 (2)	0.0195 (6)
C11	1.2629 (6)	1.1010 (4)	0.1327 (3)	0.0276 (7)
H11A	1.1457	1.0163	0.0921	0.041*
H11C	1.4305	1.0685	0.1229	0.041*
H11D	1.2470	1.1953	0.1051	0.041*
C12	1.5687 (5)	1.3582 (4)	0.3386 (3)	0.0243 (7)
H12A	1.6191	1.4202	0.4124	0.036*
H12D	1.5285	1.4287	0.2920	0.036*
H12B	1.7034	1.2963	0.3075	0.036*
H1O2	0.722 (11)	0.820 (7)	0.132 (5)	0.080 (18)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
O1	0.0194 (11)	0.0238 (11)	0.0233 (11)	−0.0060 (8)	0.0019 (8)	0.0042 (8)
O2	0.0250 (12)	0.0281 (11)	0.0232 (11)	−0.0040 (9)	0.0061 (9)	0.0028 (9)
N1	0.0170 (12)	0.0148 (11)	0.0261 (13)	0.0009 (9)	0.0020 (9)	0.0041 (9)
N2	0.0207 (13)	0.0246 (13)	0.0290 (14)	−0.0061 (10)	−0.0003 (10)	0.0062 (10)
C1	0.0155 (14)	0.0176 (13)	0.0270 (15)	0.0054 (10)	0.0036 (11)	0.0036 (11)
C2	0.0152 (14)	0.0204 (14)	0.0318 (16)	0.0021 (11)	0.0054 (11)	0.0078 (12)
C3	0.0159 (14)	0.0225 (14)	0.0353 (17)	−0.0013 (11)	−0.0012 (12)	0.0063 (12)
C4	0.0247 (16)	0.0227 (15)	0.0246 (15)	−0.0006 (12)	−0.0007 (12)	0.0004 (12)
C5	0.0164 (14)	0.0194 (14)	0.0242 (14)	0.0026 (11)	0.0021 (11)	0.0052 (11)
C6	0.0154 (13)	0.0155 (13)	0.0256 (14)	0.0033 (10)	0.0019 (11)	0.0054 (11)
C7	0.0199 (14)	0.0158 (13)	0.0216 (14)	0.0058 (11)	0.0019 (11)	0.0034 (10)
C8	0.0140 (13)	0.0163 (13)	0.0237 (14)	0.0051 (10)	0.0029 (10)	0.0056 (10)
C9	0.0159 (13)	0.0169 (13)	0.0262 (15)	0.0037 (10)	0.0033 (11)	0.0074 (11)
C10	0.0136 (13)	0.0169 (13)	0.0296 (15)	0.0038 (10)	0.0020 (11)	0.0079 (11)
C11	0.0272 (16)	0.0291 (16)	0.0260 (16)	0.0009 (13)	0.0080 (12)	0.0055 (12)
C12	0.0137 (13)	0.0215 (14)	0.0392 (17)	0.0005 (11)	0.0038 (12)	0.0100 (12)

Geometric parameters (Å, º) top

O1—C8	1.357 (3)	C4—H4A	0.9300
O1—N2	1.429 (3)	C5—C6	1.412 (4)
O2—C5	1.353 (4)	C6—C7	1.452 (4)
O2—H1O2	0.95 (6)	C7—H7A	0.9300
N1—C7	1.293 (4)	C8—C9	1.367 (4)
N1—C8	1.381 (4)	C9—C10	1.426 (4)
N2—C10	1.308 (4)	C9—C11	1.491 (4)
C1—C2	1.385 (4)	C10—C12	1.498 (4)
C1—C6	1.410 (4)	C11—H11A	0.9600
C1—H1A	0.9300	C11—H11C	0.9600
C2—C3	1.394 (4)	C11—H11D	0.9600
C2—H2A	0.9300	C12—H12A	0.9600
C3—C4	1.387 (4)	C12—H12D	0.9600
C3—H3A	0.9300	C12—H12B	0.9600
C4—C5	1.404 (4)

C8—O1—N2	107.7 (2)	N1—C7—H7A	119.1
C5—O2—H1O2	103 (3)	C6—C7—H7A	119.1
C7—N1—C8	120.3 (2)	O1—C8—C9	110.8 (2)
C10—N2—O1	105.3 (2)	O1—C8—N1	119.7 (2)
C2—C1—C6	121.2 (3)	C9—C8—N1	129.5 (3)
C2—C1—H1A	119.4	C8—C9—C10	103.2 (3)
C6—C1—H1A	119.4	C8—C9—C11	128.4 (3)
C1—C2—C3	118.9 (3)	C10—C9—C11	128.4 (3)
C1—C2—H2A	120.6	N2—C10—C9	112.9 (3)
C3—C2—H2A	120.6	N2—C10—C12	119.8 (3)
C4—C3—C2	121.6 (3)	C9—C10—C12	127.3 (3)
C4—C3—H3A	119.2	C9—C11—H11A	109.5
C2—C3—H3A	119.2	C9—C11—H11C	109.5
C3—C4—C5	119.7 (3)	H11A—C11—H11C	109.5
C3—C4—H4A	120.2	C9—C11—H11D	109.5
C5—C4—H4A	120.2	H11A—C11—H11D	109.5
O2—C5—C4	118.4 (3)	H11C—C11—H11D	109.5
O2—C5—C6	121.9 (3)	C10—C12—H12A	109.5
C4—C5—C6	119.6 (3)	C10—C12—H12D	109.5
C1—C6—C5	119.0 (3)	H12A—C12—H12D	109.5
C1—C6—C7	118.8 (3)	C10—C12—H12B	109.5
C5—C6—C7	122.2 (3)	H12A—C12—H12B	109.5
N1—C7—C6	121.8 (3)	H12D—C12—H12B	109.5

C8—O1—N2—C10	−0.3 (3)	N2—O1—C8—C9	0.3 (3)
C6—C1—C2—C3	1.3 (4)	N2—O1—C8—N1	−179.4 (2)
C1—C2—C3—C4	−0.6 (5)	C7—N1—C8—O1	−0.3 (4)
C2—C3—C4—C5	−0.3 (5)	C7—N1—C8—C9	−179.9 (3)
C3—C4—C5—O2	−179.3 (3)	O1—C8—C9—C10	−0.2 (3)
C3—C4—C5—C6	0.5 (4)	N1—C8—C9—C10	179.4 (3)
C2—C1—C6—C5	−1.1 (4)	O1—C8—C9—C11	178.7 (3)
C2—C1—C6—C7	179.4 (3)	N1—C8—C9—C11	−1.7 (5)
O2—C5—C6—C1	180.0 (3)	O1—N2—C10—C9	0.1 (3)
C4—C5—C6—C1	0.2 (4)	O1—N2—C10—C12	−179.8 (2)
O2—C5—C6—C7	−0.5 (4)	C8—C9—C10—N2	0.0 (3)
C4—C5—C6—C7	179.7 (3)	C11—C9—C10—N2	−178.9 (3)
C8—N1—C7—C6	−179.7 (2)	C8—C9—C10—C12	180.0 (3)
C1—C6—C7—N1	−176.1 (3)	C11—C9—C10—C12	1.1 (5)
C5—C6—C7—N1	4.4 (4)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1O2···N1	1.00 (9)	1.71 (8)	2.648 (5)	154 (8)

Experimental details

Crystal data
Chemical formula	C₁₂H₁₂N₂O₂
M_r	216.24
Crystal system, space group	Triclinic, P1
Temperature (K)	100
a, b, c (Å)	5.3475 (14), 8.615 (2), 12.321 (3)
α, β, γ (°)	103.696 (5), 91.486 (5), 94.059 (5)
V (Å³)	549.6 (2)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	0.09
Crystal size (mm)	0.56 × 0.14 × 0.08

Data collection
Diffractometer	Bruker APEX DUO CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2009)
T_min, T_max	0.951, 0.993
No. of measured, independent and observed [I > 2σ(I)] reflections	2467, 2467, 1946
R_int	0.000
(sin θ/λ)_max (Å⁻¹)	0.649

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.070, 0.203, 1.06
No. of reflections	2467
No. of parameters	152
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.40, −0.34

Computer programs: APEX2 (Bruker, 2009), SAINT (Bruker, 2009), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
O2—H1O2···N1	1.00 (9)	1.71 (8)	2.648 (5)	154 (8)

Footnotes

‡Thomson Reuters ResearcherID: A-3561-2009.

§On secondment to: The Center of Excellence for Advanced Materials Research, King Abdu Aziz University, Jeddah 21589, Saudi Arabia.

Acknowledgements

HKF and MH thank the Malaysian Government and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. MH thanks Universiti Sains Malaysia for a post-doctoral research fellowship. AMA, SAK and KAK thank the Chemistry Department, King Abdul Aziz University, Jeddah, Saudi Arabia, for providing research facilities. AMA would also like to thank the deanship of scientific research at KAU for grant No. 171/428.

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