Diethyl Ether → 4-Methoxybenzenethiol

Participants

Reaction Conditions

Reaction Steps

Methyl magnesium bromide (50 mL of a 3M solution in ether, 0.15 mmol) was added to a solution of the crude thiochromone (20 g, prepared in Part C above) in THF (100 mL) with cooling to 10° C. The reaction mixture was then allowed to warm to room temperature and stirred for 6 hours. The mixture was then added, with vigorous stirring, to tetrafluoroboric acid (125 mL of a 50% aqueous solution) which had been diluted with ice/water (600 mL). A yellow precipitate formed, which was collected by vacuum filtration, washed thoroughly with hexanes and dried under reduced pressure to yield the desired salt (18.5 g, 55% yield over three steps from the 4-methoxybenzene thiol). The structure of this compound was confirmed by mass spectroscopy and by 1H and 13C NMR spectroscopy.

Provenance & Evidence