N-(4-Bromo-2-methyl­phen­yl)pivalamide

Wei-Xia Qing; Wei Zhang

doi:10.1107/S1600536809034345

. 2009 Sep 5;65(Pt 10):o2313. doi: 10.1107/S1600536809034345

N-(4-Bromo-2-methylphenyl)pivalamide

Wei-Xia Qing ^a,^*, Wei Zhang ^b

PMCID: PMC2970459 PMID: 21577784

Abstract

The conformation of the N—H bond in the title compound, C₁₂H₁₆BrNO, is syn to the ortho-methyl substituent. There are two unique molecules in the asymmetric unit. In the crystal structure, intermolecular N—H⋯O hydrogen bonds link the molecules, forming infinite chains down [010].

Related literature

For a study of the effect of ring and side-chain substitution on the crystal structures of aromatic amides, see: Gowda et al. (2007 ▶). For related structures, see: Gowda et al. (2007a ▶,b ▶,c ▶).

Experimental

Crystal data

C₁₂H₁₆BrNO
M _r = 270.17
Monoclinic,
a = 11.764 (3) Å
b = 19.584 (5) Å
c = 12.956 (3) Å
β = 117.877 (19)°
V = 2638.5 (11) Å³
Z = 8
Mo Kα radiation
μ = 3.09 mm⁻¹
T = 293 K
0.42 × 0.37 × 0.32 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 2001 ▶) T _min = 0.357, T _max = 0.438
24481 measured reflections
4634 independent reflections
1875 reflections with I > 2σ(I)
R _int = 0.113

Refinement

R[F ² > 2σ(F ²)] = 0.064
wR(F ²) = 0.211
S = 1.01
4634 reflections
271 parameters
65 restraints
H-atom parameters constrained
Δρ_max = 0.90 e Å⁻³
Δρ_min = −0.70 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT-Plus (Bruker, 2001 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809034345/at2861sup1.cif

e-65-o2313-sup1.cif^{(20.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809034345/at2861Isup2.hkl

e-65-o2313-Isup2.hkl^{(227KB, 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—H1A⋯O2ⁱ	0.86	2.14	2.989 (8)	170
N2—H2B⋯O1ⁱⁱ	0.86	2.14	2.943 (8)	155

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

supplementary crystallographic information

Comment

As part of a study of the effect of ring and side chain substitutions on the crystal structures of chemically and biologically important class of compounds such as aromatic amides (Gowda, Kozisek et al., 2007), We now report the the crystal structure of the title compound, (I).

As shown in Fig.1, the title compound includes both the ortho-methyl and the p-Br-substituted phenyl group and an imide group. The title compound, (I), (Fig. 1) is structural isomer of both the 2-chloro and the 3-chloro substituent in N-(2,3-dichlorophenyl)acetamide (Gowda et al., 2007a) and N-(2,3-Dichlorophenyl)-2,2,2-trimethylacetamide (Gowda et al., 2007b). The conformation of the N–H bond in the title compound is syn to the ortho-methyl substituent, similar to that in both the 2-chloro and the 3-chloro-substituted amides, but in contrast to the anti conformation observed for the corresponding 3-chloro-substituted N-(3-Chlorophenyl)-2,2,2-trimethylacetamide (Gowda et al., 2007c). The amide H atom is involved in an intramolecular hydrogen bond with the O atom of the carbonyl group.

In the crystal structure, these molecules are linked into infinite one-dimensional chains by intermolecular N–H···O hydrogen bonds running along [010] direction (Fig. 2, Table 1).

Experimental

2,2,2-Trimethyl-N-(2-methylphenyl)acetamide (0.95 5 g, 5 mmol) was added slowly by cannulation to a stirred suspension of p-nitroaniline (0.690 g, 3 mmol) in chloroform (50 ml) at room temperature. After stirring for 2 h the solution was quenched with saturated aqueous sodium bicarbonate solution (20 ml) the layers were separated and the aqueous layer was extracted with chloroform, the combined organic extracts were washed with water (20 ml), dried (MgSO₄) and evaporated under reduced pressure to give the crude product as viscous brown oil. Then purification by short column chromatography (chloroform) and recrystallization from chloroform gave the compound (I) as brown needles crystals (1.094 g, 81%).