(E)-2-[4-tert-Butyl-5-(2,4,5-trimethoxybenzyl)thiazol-2-yliminomethyl]phenol

In the title compound, C24H28N2O4S, the dihedral angle between the phenol ring and the thiazole ring system is 10.6 (1)°, and the trimethoxyphenyl group is approximately perpendicular to the thiazole ring, the dihedral angle being 84.7 (2)°. There is a strong intramolecular hydrogen-bonding interaction between the Schiff base and the hydroxy group.

In the title compound, C 24 H 28 N 2 O 4 S, the dihedral angle between the phenol ring and the thiazole ring system is 10.6 (1) , and the trimethoxyphenyl group is approximately perpendicular to the thiazole ring, the dihedral angle being 84.7 (2) . There is a strong intramolecular hydrogen-bonding interaction between the Schiff base and the hydroxy group. 24 restraints H-atom parameters constrained Á max = 0.24 e Å À3 Á min = À0.16 e Å À3 Table 1 Hydrogen-bond geometry (Å , ).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SG2213).

Comment
Thiazoles exhibit a wide range of biological activities and Schiff bases play an important role in many biological processes (More et al., 2001). Schiff bases from benzaldehyde nitrogen mustards and p-aminophenylthiazole were reported to have significant anticancer activity (Modi et al., 1971). As part of our research program concerning the anticancer behaviour of thiazole Schiff bases, the title compound (I) has been synthesized and characterized (Fig. 1).
Geometric parameters are in the normal ranges. The length of C=N double bond is 1.280 (3) Å. The dihedral angle between the phenol group and the thiazole ring system is 10.6 (1)°, and the 2,4,5-trimethoxybenzyl group is approximately perpendicular to the thiazole ring with a dihedral angle of 84.7 (2)°. There is a strong intramolecular hydrogen bond between the nitrogen atom of Schiff base and the hydroxy group (Table 1). Packing diagram of (I) in a unit cell is shown in Fig. 2.

425-426 K.
Crystals suitable for X-ray structure determination were obtained by slow evaporation of an ethanol solution at room temperature.

Refinement
The  Fig. 1. The molecular structure of (I), with atom labels and 30% probability displacement ellipsoids for non-H atoms.   Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.