N,N′-Bis(3-methyl­phen­yl)succinamide dihydrate

B S Saraswathi; Sabine Foro; B Thimme Gowda

doi:10.1107/S1600536811020940

. 2011 Jun 4;67(Pt 7):o1591. doi: 10.1107/S1600536811020940

N,N′-Bis(3-methylphenyl)succinamide dihydrate

B S Saraswathi ^a, Sabine Foro ^b, B Thimme Gowda ^a,^*

PMCID: PMC3152126 PMID: 21836999

Abstract

The asymmetric unit of the title compound, C₁₈H₂₀N₂O₂·2H₂O, contains half a molecule with a center of symmetry at the mid-point of the central C—C bond. The N—H bonds in the amide fragments are anti to the meta-methyl groups in the adjacent benzene rings. The dihedral angle between the benzene ring and the NH—C(O)—CH₂ segment in the two halves of the molecule is 5.6 (4)°. In the crystal, the packing of molecules through O—H⋯O and N—H⋯O hydrogen-bonding interactions leads to the formation of layers parallel to the bc plane. The methyl group is disordered with respect to the 3- and 5-positions of the benzene ring, with site-occupation factors of 0.910 (8) and 0.090 (8).

Related literature

For the study of the effect of substituents on the structures of N-(aryl)-amides, see: Gowda et al. (2000 ▶); Saraswathi et al. (2011a ▶,b ▶). For the effect of substituents on the structures of N-(aryl)methanesulfonamides, see: Gowda et al. (2007 ▶). For similar structures, see: Pierrot et al. (1984 ▶).

Experimental

Crystal data

C₁₈H₂₀N₂O₂·2H₂O
M _r = 332.39
Monoclinic,
a = 13.401 (4) Å
b = 4.937 (2) Å
c = 14.446 (4) Å
β = 108.67 (3)°
V = 905.5 (5) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.48 × 0.12 × 0.04 mm

Data collection

Oxford Diffraction Xcalibur diffractometer with a Sapphire CCD detector
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2009 ▶) T _min = 0.960, T _max = 0.997
2857 measured reflections
1679 independent reflections
797 reflections with I > 2σ(I)
R _int = 0.064

Refinement

R[F ² > 2σ(F ²)] = 0.126
wR(F ²) = 0.159
S = 1.23
1679 reflections
123 parameters
10 restraints
H-atom parameters constrained
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 ▶); data reduction: CrysAlis RED; 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: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536811020940/wm2494sup1.cif

e-67-o1591-sup1.cif^{(15.2KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811020940/wm2494Isup2.hkl

e-67-o1591-Isup2.hkl^{(82.8KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811020940/wm2494Isup3.cml

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—H1N⋯O2ⁱ	0.86	2.10	2.946 (6)	169
O2—H21⋯O2ⁱⁱ	0.82	2.08	2.836 (4)	153
O2—H22⋯O1	0.84	1.87	2.713 (5)	178

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

Acknowledgments

BSS thanks the University Grants Commission, Government of India, New Delhi, for the award of a research fellowship under its faculty improvement program.

supplementary crystallographic information

Comment

The amide and sulfonamide moieties are important constituents of many biologically significant compounds. As a part of studying the substituent effects on the structures of this class of compounds (Gowda et al., 2000, 2007; Saraswathi et al., 2011a, b), in the present work, the structure of N,N-bis(3-methylphenyl)-succinamide dihydrate, (I), has been determined (Fig.1). The asymmetric unit of (I) contains half a molecule with a center of symmetry at the mid-point of the central C—C bond, similar to that observed in bis(2-chlorophenylaminocarbonylmethyl)disulfide, (II), (Pierrot et al., 1984), N,N-bis(2-methylphenyl)- succinamide, (III), (Saraswathi et al., 2011a) N,N- bis(3-chlorophenyl)-succinamide (IV) (Saraswathi et al., 2011b).

In the C—NH—C(O)—C segment, the amide O atom is anti to the H atoms attached to the adjacent C atom. The N—H bonds in the amide fragments are also anti to the meta-methyl groups in the adjacent benzene rings, similar to that observed with respect to the ortho-methyl groups in (III) and the meta-chloro groups in (IV).

The dihedral angle between the benzene ring and the NH—C(O)—CH₂ segment in the two halves of the molecule is 5.6 (4)°, compared to the values of 62.1 (2)° in (III) and 32.8 (1)° in (IV). The striking difference may be due to the fact that the title compound is the dihydrate, i.e. is composed of the amide and lattice water molecules, which, unlike in other compounds, influence the molecular conformation through hydrogen bonding interactions.

The torsion angles of N1–C7–C8–C8a and O1–C7–C8–C8a in (I) are 175.9 (6)° and -5.3 (9)°, compared to the values of 150.9 (3)° and -30.5 (4)° in (III) and -175.4 (2)° and 5.9 (4)° in (IV). The differences in the torsion angles may be due to the steric hindrances caused by the different substituents.

Similarly, the torsion angles of C2—C1—N1—C7 and C6—C1—N1—C7 are 5.4 (9)° and -173.6 (6)°, compared to the values of -64.0 (4)° and 117.6 (3)° in (III) and -35.0 (3)° and 147.5 (2)° in (IV).

The crystal packing of (I), through N1—H1N···O2, O2—H21···O2 and O2—H22···O1 hydrogen bonding (Table 1), leads to the formation of layers parallel to the bc plane and is shown in Fig. 2.

Experimental

Succinic anhydride (0.01 mol) in toluene (25 ml) was treated dropwise with m-toluidine (0.01 mol) also in toluene (20 ml) with constant stirring. The resulting mixture was stirred for one hour and set aside for an additional hour at room temperature for completion of the reaction. The mixture was then treated with dilute hydrochloric acid to remove unreacted m-toluidine. The resultant N-(3-methylphenyl)succinamic acid was filtered under suction and washed thoroughly with water to remove the unreacted succinic anhydride and succinic acid. The compound was recrystallized to a constant melting point from ethanol. The purity of the compound was checked by elemental analysis and characterized by its infrared and NMR spectra.

The N-(3-methylphenyl)succinamic acid obtained was then treated with phosphorous oxychloride and excess of m-toluidine at room temperature with constant stirring. The resultant mixture was stirred for 4 h, kept aside for additional 6 h for completion of the reaction and poured slowly into crushed ice with constant stirring. It was kept aside for a day. The resultant solid, N,N-bis(3-methylphenyl)-succinamide dihydrate, was filtered under sucction, washed thoroughly with water, dilute sodium hydroxide solution and finally with water. It was recrystallized to a constant melting point from a mixture of acetone and chloroform. The purity of the compound was checked by elemental analysis, and characterized by its infrared and NMR spectra.

Needle-like colorless single crystals used in the X-ray diffraction studies were grown in a mixture of acetone and chloroform at room temperature.