4-TRIMETHYLSILYL-THIOANISOLE synthesis

Yield:22515-25-9 95%

Reaction Conditions:

Stage #1: (4-bromophenyl)thioanisolewith iodine;magnesium;ethylene dibromide in diethyl ether;
Stage #2: chloro-trimethyl-silane in diethyl ether;Reflux;

Steps:

4.2.1. 4-tert-Butylphenyltrimethylsilane 1 (R=^tBu)

General procedure: This derivative was prepared by the method outlined by Eaborn.36 C. Eaborn, J. Chem. Soc. (1956), pp. 4858-4864. Full Text via CrossRef³⁶ To Mg turnings (2.05 g, 85.5 mmol) suspended with stirring in dry ether (50 mL) was rapidly added 1-bromo-4-tert-butylbenzene (15.2 g, 71.0 mmol) in dry ether (50 mL). A small amount of iodine and 1,2-dibromoethane (3 drops) were added to initiate the reaction, and dry ether (100 mL) was then rapidly added. When formation of the Grignard reagent was complete, trimethylsilyl chloride (7.74 g, 71.0 mmol) in dry ether (50 mL) was added over 30 min. The mixture was then stirred and heated under reflux overnight. Most of the solvent was then evaporated and the residue treated with satd aq NH₄Cl solution (50 mL). The ether layer was separated and the aqueous layer extracted with ether (2×50 mL). The combined ether layers were dried (MgSO₄) and evaporation gave a solid product, which after recrystallisation from EtOH/H₂O was identified as compound 1 (R=^tBu) (12.2 g, 83%), colourless crystals, mp 78 °C [lit.,³⁶ 78 °C]; ¹H NMR (CDCl₃) δ 0.31 (s, 9H, SiMe₃), 1.37 (s, 9H, CMe₃) and 7.48 (dd J 8.3 Hz, 4H, ArH); IR (KBr) ν_max/cm^-1 3050, 2960, 1250, 838 and 759; MS (EI) m/z 206 (M⁺) (10%), 191 (100%). Anal. Calcd for C₁₃H₂₂Si: C, 75.65; H, 10.74. Found: C, 75.70; H, 10.70%.

References:

Lothian, Aileen P.;Ramsden, Christopher A.;Shaw, Maxine M.;Smith, Rachel G. [Tetrahedron,2011,vol. 67,# 15,p. 2788 - 2793] Location in patent:experimental part