5-[(3,4-Dimethoxy­benzyl)­aminomethyl­ene]-2,2-dimethyl-1,3-dioxane-4,6-dione

Rui Li; Jian-You Shi; Zhen-Yu Ding; Yu-Quan Wei; Jian Ding

doi:10.1107/S1600536809017413

. 2009 May 14;65(Pt 6):o1298–o1299. doi: 10.1107/S1600536809017413

5-[(3,4-Dimethoxybenzyl)aminomethylene]-2,2-dimethyl-1,3-dioxane-4,6-dione

Rui Li ^a,^*, Jian-You Shi ^b, Zhen-Yu Ding ^a, Yu-Quan Wei ^a, Jian Ding ^c

PMCID: PMC2969602 PMID: 21583157

Abstract

The title compound, C₁₅H₁₇NO₆, is approximately planar, with dihedral angles of 3.11 (4) and 2.12 (4)° between the connecting aminomethylene unit and the planar part of the dioxane ring, and between the dimethoxybenzyl ring and the aminomethylene group, respectively. The dioxane ring exhibits a half-boat conformation, in which the C atom between the dioxane O atoms is 0.5471 (8) Å out of the plane. The molecule has an intramolecular N—H⋯O hydrogen bond which may stabilize the planar conformation. In the crystal, weak intermolecular C—H⋯O hydrogen-bonding contacts, result in the formation of sheets parallel to the ab plane.

Related literature

For the synthesis of related compounds, see: Cassis et al. (1985 ▶). For the synthesis of related antitumor precursors, see Ruchelman et al. (2003 ▶). For the structure of 5-(aminomethylene)-2,2-dimethyl-1,3-dioxane-4,6-dione, see: da Silva et al. (2006 ▶). For Meldrum’s acid, see: Meldrum (1908 ▶).

Experimental

Crystal data

C₁₅H₁₇NO₆
M _r = 307.30
Monoclinic,
a = 6.270 (4) Å
b = 12.486 (4) Å
c = 19.529 (5) Å
β = 106.31 (3)°
V = 1467.3 (11) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 292 K
0.44 × 0.38 × 0.18 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: none
2852 measured reflections
2657 independent reflections
1675 reflections with I > 2σ(I)
R _int = 0.008
3 standard reflections every 150 reflections intensity decay: 1.8%

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.160
S = 1.03
2657 reflections
207 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: DIFRAC (Gabe & White, 1993 ▶); cell refinement: DIFRAC; data reduction: NRCVAX (Gabe et al., 1989 ▶); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809017413/si2171sup1.cif

e-65-o1298-sup1.cif^{(18.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809017413/si2171Isup2.hkl

e-65-o1298-Isup2.hkl^{(130.5KB, 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—H1N⋯O3	0.86 (3)	2.11 (3)	2.744 (3)	130 (2)
C9—H9⋯O4ⁱ	0.93	2.40	3.309 (4)	164
C15—H15C⋯O3ⁱⁱ	0.96	2.59	3.528 (4)	166

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

Acknowledgments

This research was supported financially by the State Key Laboratory of Drug Research (Shanghai Institute of Materia Medica, Chinese Academy of Sciences).

supplementary crystallographic information

Comment

The 4(1H)quinolone structure plays an extremely important role in the field of pharmaceutical chemistry. These compounds have been used as precursors for anticancer agents, anti-malarial agents and reversible (H+/K+) ATPase inhibitors (Ruchelman et al.,2003). 5-arylaminomethylene-2,2-dimethyl-1,3-dioxane-4,6-diones are the key intermediates which can be used to synthesize the 4(1H)quinolone derivatives by thermolysis (Cassis et al., 1985).

In the structure of the title molecule (Fig. 1), it is approximately planar with the dihedral angles of 3.11 (4)° and 2.12 (4)° between the connecting aminomethylene unit and the planar part of the dioxane ring, and between the dimethoxybenzyl ring and the aminomethylene group, respectively. Besides, the dioxane ring of the title compound exhibits a half-boat conformation, in which the C atom between the dioxane O atoms is -0.5471 (8) Å out-of-plane.

The intramolecular N—H···O hydrogen bond (Table 1) is stabilizing the planar conformation in the molecule. Intermolecular weak C—H···O hydrogen bonding contacts (Table 1) result in the formation of sheets running parallel to the a-b plane in the crystal structure (Fig. 2).

Experimental

A solution of 2,2-dimethyl-1,3-dioxane-4,6-dione (Meldrum's acid) and methylorthoformate was heated to reflux for two hours and immediately the arylamine was added in an equimolar amount relative to Meldrum's acid. The mixture was heated under reflux for another 5–8 h; single recrystallization from methanol gave the corresponding arylaminomethylene derivative as analytically pure material.