Hydrochloric Acid → 5,7-di-tert-butyl-3-(4-methylthiophenyl)-3H-benzofuran-2-one

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A solution of 26.2 g (0.10 mol) of 5,7-di-tert-butyl-3-hydroxy-3H-benzofuran-2-one (compound (20(1), Table 2, Example 1a) in 25 ml (0.21 mol) of thioanisole is added dropwise to a solution of 14.7 g (0.11 mol) of aluminium chloride in 15 ml (0.13 mol) of thioanisole at 35°-40° C. The reaction mixture is thereafter stirred for 30 minutes at 30° C. and for 2 hours at 80° C., and then after cooling, c. 50 ml of water and then concentrated hydrochloric acid and methylene chloride are added cautiously in sufficient amount to form a homogeneous two-phase mixture. The organic phase is separated, washed with water, dried over sodium sulfate and concentrated on a vacuum rotary evaporator. Crystallisation of the residue from ethanol yields 6.7 g (18%) of 5,7-di-tert-butyl-3-(4-methylthiophenyl)-3H-benzofuran-2-one, m.p. 125°-131° C. (compound (108), Table 1).

Herkunft & Nachweise