Sulfuric Acid → 2,2,4,4-Tetramethyl-6-bromothiochroman

Participants

Reaction Steps

A mixture of 500 mg (1.49 mmol) of 4-bromo-2-(1,1,3-trimethyl-3-hydroxybutyl) thiophenol (Compound 71) and 8 ml of 20 percent aqueous H2SO4 was heated at reflux for 24 h. The mixture was extracted with hexanes the organic extracts were combined and washed successively with water, saturated NaHCO3, water again, saturated NaCl and then dried (MgSO4). The solvent was removed in vacuo and the residue purified by flash chromatography (silica; hexanes) to give the title compound as a colorless oil. PMR (CDCl3): δ 1.35 (6H, s), 1.40 (6H, s) 1.93 (2H, s), 7.17 (1H, dd, J-8.4 Hz, 2.1 Hz), 7.23 (1H, d, J~8.4 Hz), 7.26 (1H, d, J~2.1 Hz). MS exact mass, m/e 284.0221 (calcd. for C13H17 S Br, 284.0234).

Provenance & Evidence