1-[2-(Carboxy­meth­oxy)phen­yl]-N-(4-chloro­phen­yl)methanimine oxide

Janet M S Skakle; Edward R T Tiekink; James L Wardell; Solange M S V Wardell

doi:10.1107/S160053680905137X

. 2009 Dec 4;66(Pt 1):o45–o46. doi: 10.1107/S160053680905137X

1-[2-(Carboxymethoxy)phenyl]-N-(4-chlorophenyl)methanimine oxide¹

Janet M S Skakle ^a, Edward R T Tiekink ^b,^*, James L Wardell ^c, Solange M S V Wardell ^d

PMCID: PMC2980074 PMID: 21580149

Abstract

In the title resonance conformer, C₁₅H₁₂ClNO₄, the central C–N bond [1.297 (2) Å] has considerable double-bond character and the N–O bond [1.3215 (18) Å] indicates formal negative charge on the oxygen atom. Considerable deviations from co-planarity are evident in the molecule, with both benzene rings twisted out of the central C–C–N–C plane [the dihedral angle formed between the rings = 81.99 (8)°]. Similarly, the carboxylic acid residue occupies a position almost normal to the plane of the benzene ring to which it is connected [C—C—O—C torsion angle = −78.42 (17)°]. The most prominent intermolecular interactions involve the carboxylic acid the N⁺–O⁻ residues with the O—H⋯O hydrogen bonds leading to helical supramolecular chains along the b axis. These chains are connected into layers via C–H⋯O_carbonyl interactions and the layers are consolidated into the crystal structure by C–H⋯Cl contacts.

Related literature

For the synthesis, see: Forrester et al. (1974 ▶).

Experimental

Crystal data

C₁₅H₁₂ClNO₄
M _r = 305.72
Monoclinic,
a = 7.6631 (2) Å
b = 19.3034 (5) Å
c = 9.6305 (3) Å
β = 107.083 (1)°
V = 1361.73 (7) Å³
Z = 4
Mo Kα radiation
μ = 0.30 mm⁻¹
T = 120 K
0.26 × 0.14 × 0.12 mm

Data collection

Bruker–Nonius 95mm CCD camera on κ-goniostat diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2003 ▶) T _min = 0.760, T _max = 1.000
15210 measured reflections
3113 independent reflections
2589 reflections with I > 2σ(I)
R _int = 0.043

Refinement

R[F ² > 2σ(F ²)] = 0.038
wR(F ²) = 0.109
S = 1.10
3113 reflections
191 parameters
H-atom parameters constrained
Δρ_max = 0.40 e Å⁻³
Δρ_min = −0.46 e Å⁻³

Data collection: COLLECT (Hooft, 1998 ▶); cell refinement: DENZO (Otwinowski & Minor, 1997 ▶) and COLLECT; data reduction: DENZO and COLLECT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680905137X/pb2014sup1.cif

e-66-00o45-sup1.cif^{(18.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680905137X/pb2014Isup2.hkl

e-66-00o45-Isup2.hkl^{(149.6KB, 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
O2—H2⋯O4ⁱ	0.84	1.76	2.5834 (17)	167
C2—H2a⋯O1ⁱⁱ	0.99	2.29	3.205 (2)	154
C9—H9⋯Cl1ⁱⁱⁱ	0.95	2.71	3.5538 (16)	148

Open in a new tab

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

Acknowledgments

The use of the EPSRC X-ray crystallographic service at the University of Southampton, England and the valuable assistance of the staff there is gratefully acknowledged. JLW acknowledges support from CAPES (Brazil).

supplementary crystallographic information

Comment

The title compound (I) and other N-(2-carboxymethoxybenzylidene)aniline N-oxides are useful precursors of 4-aryl-2H-1,4-benzoxazin-3(4H)-ones on photolysis in the presence of persulfate.

The C9–N1 bond distance of 1.297 (2) Å in (I), Fig. 1, indicates significant double bond character is this bond, and the N1–O4 distance of 1.3215 (18) Å is indicative of significant negative charge on the O4 centre, indicating that (I) exists primarily as a zwitterion. The molecular structure of (I) displays considerable deviations from co-planarity of the various residues. Thus, while the central moiety is planar as seen in the C4/C9/N1/C10 torsion angle of 176.07 (14) °, both phenyl substituents are twisted out of this plane as seen in the N1/C9/C4/C3 and C9/N1/C10/C11 torsion angles of 161.63 (15) and -60.8 (2) °, respectively. The carboxylic acid residue occupies a position approximately normal to the plane of the C3—C8 phenyl ring as seen in the C1/C2/O3/C3 torsion angle of -78.42 (17) °. The most prominent hydrogen bonding interactions are of the type O–H···O and occur between the carboxylic acid-O2–H and N–O^- atoms. These lead to supramolecular helical chains aligned along the b axis, Table 1 and Fig. 2. Connections between chains are afforded by C–H···O2 interactions leading to undulating supramolecular arrays in the bc plane, Table 1 and Fig. 3, with the chloride atoms lying to either side. Layers stack along the a direction being held in place by C–H···Cl contacts, Table 1 and Fig. 4.

Experimental

The compound was prepared according to a published procedure (Forrester et al., 1974) from 2-H(O)CC₆H₄OCH₂CO₂H and 4-ClC₆H₄NHOH, m. pt. 484–485 K, lit. value 480–482 K. The sample used in the structure determination was grown from EtOH solution.