5-(3,4-Dimethyl­benzyl­idene)-2,2-dimethyl-1,3-dioxane-4,6-dione

Abstract

The title compound, C₁₅H₁₆O₄, was prepared by the reaction of 2,2-dimethyl-1,3-dioxane-4,6-dione and 3,4-dimethyl­benzaldehyde in ethanol. The 1,3-dioxane ring exhibits an envelope conformation. In the crystal, mol­ecules are linked by weak inter­molecular C—H⋯O hydrogen bonds, forming chains parallel to the b axis.

Related literature

For related structures, see: Zeng (2010 ▶, 2011 ▶).

Experimental

Crystal data

• C₁₅H₁₆O₄

• M _r = 260.28

• Monoclinic,

• a = 16.8249 (15) Å

• b = 7.1390 (6) Å

• c = 11.7101 (11) Å

• β = 108.612 (1)°

• V = 1333.0 (2) ų

• Z = 4

• Mo Kα radiation

• μ = 0.09 mm⁻¹

• T = 298 K

• 0.45 × 0.32 × 0.30 mm

Data collection

• Bruker SMART CCD area-detector diffractometer

• Absorption correction: multi-scan (SADABS; Bruker, 1997 ▶) T _min = 0.959, T _max = 0.972

• 6611 measured reflections

• 2341 independent reflections

• 1330 reflections with I > 2σ(I)

• R _int = 0.040

Refinement

• R[F ² > 2σ(F ²)] = 0.048

• wR(F ²) = 0.201

• S = 1.09

• 2341 reflections

• 176 parameters

• H-atom parameters constrained

• Δρ_max = 0.15 e Å⁻³

• Δρ_min = −0.15 e Å⁻³

Data collection: SMART (Bruker, 1997 ▶); cell refinement: SAINT (Bruker, 1997 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Supplementary material file. DOI: 10.1107/S1600536811016497/rz2588Isup3.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
C6—H6C⋯O4i	0.96	2.58	3.447 (4)	151

Symmetry code: (i) .

supplementary crystallographic information

Comment

In previous papers, the crystal structure of 5-(4-hydroxybenzylidene)-2,2-dimethyl-1,3-dioxane-4,6-dione (Zeng, 2010) and 2,2-dimethyl-5-[(5-methylfuran-2-yl)methylidene]-1,3-dioxane-4,6-dione (Zeng, 2011) have been reported. As part of this ongoing search for new Meldrum's acid compounds, the title compound has been synthesized and its structure is reported here.

In the title compound (Fig. 1), bond lengths and angles fall in the usual ranges. The 1,3-dioxane ring exhibits an envelope conformation with the dimethyl-substituted carbon C4 atom forming the flap. In the crystal structure, the molecules interact through a weak intermolecular C—H···O hydrogen bond (Table 1) to form chains parallel to the b axis.

Experimental

The mixture of malonic acid (6.24 g, 0.06 mol) and acetic anhydride (9 ml) in concentrated sulfuric acid (0.25 ml) was stirred with water at 303K. After dissolving, propan-2-one (3.48 g, 0.06 mol) was added dropwise into the solution and the reaction was allowed to proceed for 2 h. The mixture was then cooled and filtered, and an ethanol solution of 3,4-dimethylbenzaldehyde (8.04 g, 0.06 mol) was added. The solution was then filtered and concentrated. Single crystals were obtained by slow evaporation of a petroleum ether/ethylacetate (4:1 v/v) solution at room temperature over a period of several days.

Refinement

The H atoms were placed in calculated positions (C—H = 0.93–0.96 Å), and refined as riding with U_iso(H) = 1.2 U_eq(C) or 1.5 U_eq(C) for methyl H atoms.

Figures

Fig. 1.

The molecular structure of the title compound, with displacement ellipsoids drawn at the 30% probability level.

Crystal data

C15H16O4	F(000) = 552
Mr = 260.28	Dx = 1.297 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1211 reflections
a = 16.8249 (15) Å	θ = 2.6–21.6°
b = 7.1390 (6) Å	µ = 0.09 mm−1
c = 11.7101 (11) Å	T = 298 K
β = 108.612 (1)°	Block, yellow
V = 1333.0 (2) Å3	0.45 × 0.32 × 0.30 mm
Z = 4

Data collection

Bruker SMART CCD area-detector diffractometer	2341 independent reflections
Radiation source: fine-focus sealed tube	1330 reflections with I > 2σ(I)
graphite	Rint = 0.040
φ and ω scans	θmax = 25.0°, θmin = 2.6°
Absorption correction: multi-scan (SADABS; Bruker, 1997)	h = −19→20
Tmin = 0.959, Tmax = 0.972	k = −8→8
6611 measured reflections	l = −13→11

Refinement

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.048	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.201	H-atom parameters constrained
S = 1.09	w = 1/[σ2(Fo2) + (0.0016P)2] where P = (Fo2 + 2Fc2)/3
2341 reflections	(Δ/σ)max < 0.001
176 parameters	Δρmax = 0.15 e Å−3
0 restraints	Δρmin = −0.15 e Å−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
O1	0.30755 (12)	0.6940 (3)	0.53926 (17)	0.0576 (6)
O2	0.39334 (12)	0.4548 (3)	0.50624 (17)	0.0579 (6)
O3	0.21388 (14)	0.6469 (3)	0.62839 (19)	0.0710 (7)
O4	0.39031 (14)	0.1691 (3)	0.5720 (2)	0.0791 (8)
C1	0.27252 (18)	0.5845 (4)	0.6047 (3)	0.0523 (8)
C2	0.30722 (17)	0.3945 (4)	0.6311 (3)	0.0518 (8)
C3	0.36633 (19)	0.3278 (4)	0.5704 (3)	0.0554 (8)
C4	0.38899 (17)	0.6503 (4)	0.5324 (3)	0.0508 (8)
C5	0.45580 (18)	0.6974 (5)	0.6484 (3)	0.0626 (9)
H5A	0.4516	0.8273	0.6669	0.094*
H5B	0.5100	0.6735	0.6406	0.094*
H5C	0.4486	0.6216	0.7121	0.094*
C6	0.3971 (2)	0.7532 (5)	0.4258 (3)	0.0675 (9)
H6A	0.3536	0.7135	0.3546	0.101*
H6B	0.4509	0.7270	0.4172	0.101*
H6C	0.3921	0.8854	0.4370	0.101*
C7	0.28095 (18)	0.2646 (4)	0.6950 (3)	0.0603 (9)
H7	0.3045	0.1474	0.6928	0.072*
C8	0.22436 (18)	0.2659 (4)	0.7661 (3)	0.0564 (8)
C9	0.18336 (19)	0.0988 (4)	0.7737 (3)	0.0618 (9)
H9	0.1947	−0.0067	0.7349	0.074*
C10	0.12658 (19)	0.0834 (5)	0.8362 (3)	0.0616 (9)
C11	0.11383 (19)	0.2368 (5)	0.9012 (3)	0.0629 (9)
C12	0.1564 (2)	0.3997 (5)	0.8989 (3)	0.0676 (9)
H12	0.1492	0.5014	0.9443	0.081*
C13	0.20958 (19)	0.4168 (5)	0.8313 (3)	0.0657 (9)
H13	0.2359	0.5308	0.8292	0.079*
C14	0.0815 (2)	−0.1001 (5)	0.8349 (3)	0.0894 (12)
H14A	0.1023	−0.1921	0.7918	0.134*
H14B	0.0225	−0.0828	0.7960	0.134*
H14C	0.0913	−0.1419	0.9162	0.134*
C15	0.0553 (2)	0.2249 (6)	0.9743 (3)	0.0873 (12)
H15A	0.0004	0.1895	0.9231	0.131*
H15B	0.0523	0.3446	1.0101	0.131*
H15C	0.0756	0.1329	1.0367	0.131*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0568 (12)	0.0537 (13)	0.0679 (13)	0.0146 (10)	0.0280 (10)	0.0096 (10)
O2	0.0655 (13)	0.0499 (13)	0.0608 (13)	0.0058 (10)	0.0238 (10)	−0.0083 (11)
O3	0.0672 (14)	0.0724 (17)	0.0842 (16)	0.0231 (12)	0.0395 (13)	0.0142 (12)
O4	0.0819 (17)	0.0485 (15)	0.113 (2)	0.0095 (12)	0.0404 (14)	−0.0078 (13)
C1	0.0512 (18)	0.054 (2)	0.0523 (17)	0.0059 (15)	0.0178 (14)	0.0017 (15)
C2	0.0458 (16)	0.0447 (18)	0.0641 (19)	0.0000 (13)	0.0164 (14)	−0.0030 (15)
C3	0.0544 (18)	0.045 (2)	0.066 (2)	0.0024 (15)	0.0183 (15)	−0.0080 (16)
C4	0.0535 (18)	0.0467 (19)	0.0570 (18)	0.0075 (14)	0.0241 (14)	−0.0031 (14)
C5	0.063 (2)	0.065 (2)	0.059 (2)	−0.0037 (16)	0.0175 (16)	−0.0079 (16)
C6	0.071 (2)	0.074 (2)	0.066 (2)	0.0139 (17)	0.0331 (16)	0.0138 (18)
C7	0.0519 (18)	0.0481 (19)	0.076 (2)	0.0015 (15)	0.0136 (16)	0.0016 (16)
C8	0.0520 (18)	0.048 (2)	0.065 (2)	−0.0037 (15)	0.0132 (15)	0.0094 (16)
C9	0.063 (2)	0.053 (2)	0.063 (2)	−0.0030 (15)	0.0103 (16)	0.0072 (15)
C10	0.0559 (19)	0.057 (2)	0.063 (2)	−0.0132 (15)	0.0063 (16)	0.0142 (17)
C11	0.059 (2)	0.061 (2)	0.063 (2)	0.0000 (17)	0.0122 (16)	0.0134 (18)
C12	0.074 (2)	0.060 (2)	0.070 (2)	−0.0043 (17)	0.0241 (18)	0.0107 (17)
C13	0.066 (2)	0.054 (2)	0.077 (2)	−0.0098 (16)	0.0234 (18)	0.0074 (17)
C14	0.093 (3)	0.078 (3)	0.087 (3)	−0.032 (2)	0.015 (2)	0.007 (2)
C15	0.083 (3)	0.099 (3)	0.086 (3)	−0.010 (2)	0.035 (2)	0.014 (2)

Geometric parameters (Å, °)

O1—C1	1.354 (3)	C7—H7	0.9300
O1—C4	1.432 (3)	C8—C13	1.388 (4)
O2—C3	1.346 (4)	C8—C9	1.395 (4)
O2—C4	1.436 (3)	C9—C10	1.381 (4)
O3—C1	1.193 (3)	C9—H9	0.9300
O4—C3	1.201 (3)	C10—C11	1.389 (4)
C1—C2	1.470 (4)	C10—C14	1.511 (4)
C2—C7	1.351 (4)	C11—C12	1.371 (4)
C2—C3	1.474 (4)	C11—C15	1.500 (4)
C4—C6	1.492 (4)	C12—C13	1.377 (4)
C4—C5	1.499 (4)	C12—H12	0.9300
C5—H5A	0.9600	C13—H13	0.9300
C5—H5B	0.9600	C14—H14A	0.9600
C5—H5C	0.9600	C14—H14B	0.9600
C6—H6A	0.9600	C14—H14C	0.9600
C6—H6B	0.9600	C15—H15A	0.9600
C6—H6C	0.9600	C15—H15B	0.9600
C7—C8	1.452 (4)	C15—H15C	0.9600
C1—O1—C4	120.2 (2)	C8—C7—H7	112.6
C3—O2—C4	119.1 (2)	C13—C8—C9	116.8 (3)
O3—C1—O1	117.2 (3)	C13—C8—C7	125.9 (3)
O3—C1—C2	126.7 (3)	C9—C8—C7	117.3 (3)
O1—C1—C2	115.8 (3)	C10—C9—C8	122.7 (3)
C7—C2—C1	124.8 (3)	C10—C9—H9	118.6
C7—C2—C3	115.8 (3)	C8—C9—H9	118.6
C1—C2—C3	118.7 (3)	C9—C10—C11	118.8 (3)
O4—C3—O2	118.2 (3)	C9—C10—C14	119.5 (3)
O4—C3—C2	124.9 (3)	C11—C10—C14	121.6 (3)
O2—C3—C2	116.9 (3)	C12—C11—C10	119.0 (3)
O1—C4—O2	109.8 (2)	C12—C11—C15	120.1 (3)
O1—C4—C6	106.6 (2)	C10—C11—C15	120.9 (3)
O2—C4—C6	106.0 (2)	C11—C12—C13	121.7 (3)
O1—C4—C5	110.7 (2)	C11—C12—H12	119.1
O2—C4—C5	109.7 (2)	C13—C12—H12	119.1
C6—C4—C5	113.9 (3)	C12—C13—C8	120.7 (3)
C4—C5—H5A	109.5	C12—C13—H13	119.6
C4—C5—H5B	109.5	C8—C13—H13	119.6
H5A—C5—H5B	109.5	C10—C14—H14A	109.5
C4—C5—H5C	109.5	C10—C14—H14B	109.5
H5A—C5—H5C	109.5	H14A—C14—H14B	109.5
H5B—C5—H5C	109.5	C10—C14—H14C	109.5
C4—C6—H6A	109.5	H14A—C14—H14C	109.5
C4—C6—H6B	109.5	H14B—C14—H14C	109.5
H6A—C6—H6B	109.5	C11—C15—H15A	109.5
C4—C6—H6C	109.5	C11—C15—H15B	109.5
H6A—C6—H6C	109.5	H15A—C15—H15B	109.5
H6B—C6—H6C	109.5	C11—C15—H15C	109.5
C2—C7—C8	134.7 (3)	H15A—C15—H15C	109.5
C2—C7—H7	112.6	H15B—C15—H15C	109.5
C4—O1—C1—O3	164.6 (2)	C1—C2—C7—C8	−8.5 (6)
C4—O1—C1—C2	−19.9 (4)	C3—C2—C7—C8	−179.5 (3)
O3—C1—C2—C7	−5.1 (5)	C2—C7—C8—C13	−31.0 (6)
O1—C1—C2—C7	179.9 (3)	C2—C7—C8—C9	151.5 (3)
O3—C1—C2—C3	165.6 (3)	C13—C8—C9—C10	3.9 (4)
O1—C1—C2—C3	−9.4 (4)	C7—C8—C9—C10	−178.4 (3)
C4—O2—C3—O4	−160.0 (3)	C8—C9—C10—C11	−4.5 (4)
C4—O2—C3—C2	21.6 (4)	C8—C9—C10—C14	177.0 (3)
C7—C2—C3—O4	1.7 (4)	C9—C10—C11—C12	1.6 (4)
C1—C2—C3—O4	−169.8 (3)	C14—C10—C11—C12	−180.0 (3)
C7—C2—C3—O2	180.0 (3)	C9—C10—C11—C15	−177.7 (3)
C1—C2—C3—O2	8.5 (4)	C14—C10—C11—C15	0.8 (5)
C1—O1—C4—O2	47.5 (3)	C10—C11—C12—C13	1.8 (5)
C1—O1—C4—C6	161.9 (2)	C15—C11—C12—C13	−178.9 (3)
C1—O1—C4—C5	−73.7 (3)	C11—C12—C13—C8	−2.5 (5)
C3—O2—C4—O1	−48.1 (3)	C9—C8—C13—C12	−0.4 (5)
C3—O2—C4—C6	−162.8 (2)	C7—C8—C13—C12	−177.8 (3)
C3—O2—C4—C5	73.8 (3)

Hydrogen-bond geometry (Å, °)

D—H···A	D—H	H···A	D···A	D—H···A
C6—H6C···O4i	0.96	2.58	3.447 (4)	151

Symmetry codes: (i) x, y+1, z.