Dimethyl 2-butyl-2-(3,5-di-tert-butyl-4-hydroxy­benz­yl)malonate

Tao Zeng; Wan-Zhong Ren

doi:10.1107/S1600536809035697

. 2009 Sep 12;65(Pt 10):o2429. doi: 10.1107/S1600536809035697

Dimethyl 2-butyl-2-(3,5-di-tert-butyl-4-hydroxybenzyl)malonate

Tao Zeng ^a,^*, Wan-Zhong Ren ^a

PMCID: PMC2970493 PMID: 21577885

Abstract

The title compound, C₂₅H₃₈O₅, was formed by the reaction of dimethyl 2-butylmalonate and 2,6-di-tert-butyl-4-[(dimethylamino)methyl]phenol. In the crystal structure, molecules are linked by intermolecular O—H⋯O hydrogen bonds into chains along [010].

Related literature

For background to hindered phenols and hindered amines, see: Denisov (1991 ▶); Klemchuk & Gande (1998 ▶); Yamazaki & Seguchi (1997 ▶); Rasberger (1980 ▶); Eggensperger et al. (1974 ▶, 1976 ▶). For a related structure, see: Zeng & Chen (2006 ▶).

Experimental

Crystal data

C₂₄H₃₈O₅
M _r = 406.54
Monoclinic,
a = 10.854 (2) Å
b = 10.341 (2) Å
c = 22.899 (5) Å
β = 98.838 (4)°
V = 2539.7 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 294 K
0.24 × 0.20 × 0.16 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.983, T _max = 0.988
12778 measured reflections
4475 independent reflections
2448 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.048
wR(F ²) = 0.142
S = 1.01
4475 reflections
272 parameters
12 restraints
H-atom parameters constrained
Δρ_max = 0.16 e Å⁻³
Δρ_min = −0.18 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 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809035697/lh2893sup1.cif

e-65-o2429-sup1.cif^{(23.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809035697/lh2893Isup2.hkl

e-65-o2429-Isup2.hkl^{(219.3KB, 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
O1—H1⋯O2ⁱ	0.82	2.23	2.832 (2)	130

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors greatefully acknowledge financial support from the Start Foundation (HY07B14) and the Youth Foundation (HY08Z13) by Yantai University and Yantai Science Development Project (2008302).

supplementary crystallographic information

Comment

Hindered phenols are widely used as antioxidants while hindered amines are used as light stabilizers in polymers and lubricants because of their special structures (Denisov, 1991; Klemchuk & Gande, 1998; Yamazaki & Seguchi, 1997). In a former paper (Zeng & Chen, 2006), we reported the crystal structure of bis(1,2,2,6,6-pentamethylpiperidin-4-yl)butylmalonate, a key intermediate in the peparation of 'Tinuvin 144' which is a light stabilizer of the hindered amine class that also contains an oxidant unit of the sterically hindered phenol type (Rasberger, 1980; Eggensperger et al., 1974;1976). The title compound was prepared as an intermediate when we attempted to synthesize 'Tinuvin 144' by a different route.

The molecular structure of the title compound (I) is shown in Fig. 1. The phenolic hydroxyl group is sterically hindered by the adjacent bulky tert-butyl groups as is indicated by a shorter than normal H···H contact [H1···H9B = 1.87Å]. In the crystal structure, molecules are linked by intermolecular O-H···O hydrogen bonds into one-dimensional chains along [010] (see Fig. 2).

Experimental

A mixture of bis(1,2,2,6,6-pentamethylpiperidin-4-yl) 2-butylmalonate (11.67 g,0.025 mol) and 2,6-di-tert-butyl-4-((dimethylamino)methyl)phenol (6.59 g, 0.025 mol)was dissloved in toluene (100 ml), stirred and heated to reflux. Then 0.2 g lithium amide was added and stirred for a further 4 h, followed by extraction with ether (30 ml) and drying with anhydrous magnesium sulfate. The solvent was removed by vacuum evaporation at 318 K, and the product was filtered and washed with methanol (10 ml). The title compound (I) (15.05 g) was obtained in 87.9% yield. Suitable crystals (m.p. 420–422 K) were obtained by slow evaporation of a solution of (I) in a mixture of THF and methanol.