Crystal structure of 2,2-dimethyl-N-(5-methyl­pyridin-2-yl)propanamide

Gamal A El-Hiti; Keith Smith; Amany S Hegazy; Saud A Alanazi; Benson M Kariuki

doi:10.1107/S2056989015009378

. 2015 May 23;71(Pt 6):o419–o420. doi: 10.1107/S2056989015009378

Crystal structure of 2,2-dimethyl-N-(5-methylpyridin-2-yl)propanamide

Gamal A El-Hiti ^a,^*, Keith Smith ^b, Amany S Hegazy ^b, Saud A Alanazi ^a, Benson M Kariuki ^b,^*

PMCID: PMC4459364 PMID: 26090202

Abstract

There are two molecules in the asymmetric unit of the title compound, C₁₁H₁₆N₂O. The pyridine rings and amide groups overlap almost perfectly (r.m.s. overlay fit = 0.053 Å), but the tertiary butyl groups have different orientations: in one molecule, one of the methyl C atoms is syn to the amide O atom [O—C—C—C = −0.8 (3)°] and in the other the equivalent torsion angle is 31.0 (2)°. In the crystal, the two independent molecules are linked by a pair of N—H⋯N hydrogen bonds in the form of an R ₂ ²(8) loop to form a dimer. A C—H⋯O interaction connects the dimers into [100] chains.

Keywords: crystal structure, propanamide, hydrogen bonding

Related literature

For the synthesis and spectroscopic data, see: Turner (1983 ▸). For related compounds, see: El-Hiti et al. (2015a ▸,b ▸); de Candia et al. (2013 ▸); Smith et al. (2013 ▸, 2012 ▸); Abdel-Megeed et al. (2012 ▸); Joule & Mills (2000 ▸). For the crystal structures of related compounds, see: El-Hiti et al. (2014 ▸); Seidler et al. (2011 ▸); Koch et al. (2008 ▸). graphic file with name e-71-0o419-scheme1.jpg

Experimental

Crystal data

C₁₁H₁₆N₂O
M _r = 192.26
Monoclinic,
a = 11.1969 (2) Å
b = 8.6439 (2) Å
c = 23.8844 (5) Å
β = 94.549 (2)°
V = 2304.37 (8) Å³
Z = 8
Cu Kα radiation
μ = 0.57 mm⁻¹
T = 296 K
0.47 × 0.33 × 0.11 mm

Data collection

Agilent SuperNova (Dual, Cu at zero, Atlas) diffractometer
Absorption correction: gaussian (CrysAlis PRO; Agilent, 2014 ▸) T _min = 0.925, T _max = 0.975
8391 measured reflections
4503 independent reflections
3684 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.148
S = 1.04
4503 reflections
262 parameters
H-atom parameters constrained
Δρ_max = 0.27 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2014 ▸); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS2013 (Sheldrick, 2015 ▸); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸); software used to prepare material for publication: WinGX (Farrugia, 2012 ▸).

Supplementary Material

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S2056989015009378/hb7430sup1.cif

e-71-0o419-sup1.cif^{(312.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015009378/hb7430Isup2.hkl

e-71-0o419-Isup2.hkl^{(358.7KB, hkl)}

Click here for additional data file.^{(4.5KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015009378/hb7430Isup3.cml

Click here for additional data file.^{(1.9MB, tif)}

11 16 2 . DOI: 10.1107/S2056989015009378/hb7430fig1.tif

The asymmetric unit of C₁₁H₁₆N₂O with 50% probability displacement ellipsoids for nonhydrogen atoms.

Click here for additional data file.^{(1.9MB, tif)}

. DOI: 10.1107/S2056989015009378/hb7430fig2.tif

The asymmetric unit showing N—H⋯N interactions as dotted lines.

CCDC reference: 1401551

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
N2H2AN3	0.86	2.31	3.1192(16)	156
N4H4AN1	0.86	2.25	3.0837(16)	163
C4H4O2ⁱ	0.93	2.43	3.3262(19)	160

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors extend their appreciation to the Cornea Research Chair, Department of Optometry, College of Applied Medical Sciences, King Saud University, for funding this research.

supplementary crystallographic information

S1. Introduction

Substituted pyridines are important compounds (Joule & Mills, 2000) and show a range of biological activities (de Candia et al., 2013; Abdel-Megeed et al., 2012). The pyridine ring system has been modified using various efficient and simple procedures that include the use of lithium reagents as intermediates (El-Hiti et al., 2015; Smith et al., 2013, Smith et al., 2012; Turner, 1983). The X-ray crystal structures of related compounds have been reported (El-Hiti et al., 2015; El-Hiti et al., 2014; Seidler et al., 2011; Koch et al., 2008).

S2. Experimental

S2.1. Synthesis and crystallization

2,2-Dimethyl-N-(5-methylpyridin-2-yl)propanamide was obtained in 83% yield from reaction of 2-amino-5-methylpyridine with trimethylacetyl chloride in the presence of triethylamine in dichloromethane at 0 °C for 15 minutes and then at room temperature for 2 h (Turner, 1983). The crude product was purified by column chromatography (silica gel; dichloromethane) followed by crystallization from hexane to give colourless crystals of the title compound. The NMR spectral data and elemental analyses for the title compound were identical with those previously reported (Turner, 1983).

S2.2. Refinement

H atoms were positioned geometrically and refined using a riding model with U_iso(H) constrained to be 1.2 times U_eq for the atom it is bonded to except for methyl groups where it was 1.5 times with free rotation about the C—C bond.

S3. Results and discussion

The asymmetric unit (Figure 1) consists of two independent molecules of C₁₁H₁₆N₂O. The amide group and pyridine ring within the molecule are not co-planar as indicated by the torsion angles [N1—C1—N2—C7 = 142.20 (14), N3—C12—N4—C18 = 148.58 (15)]. The two independent molecules are linked by a pair of N—H···N hydrogen bonds (Table 1, Figure 2) to form an R₂²(8) ring.