Magnesium chloride hexahydrate → 4-Bromo-2-methylthiobenzamide

To a slurry solution of sodium hydrosulphide (2.80 g, 50 mmol) and magnesium chloride hexahydrate (5.05 g, 25 mmol) in dimethylformamide (50 ml) is added 4-bromo-2-methyl benzonitrile (4.90 g, 50 mmol) in one portion and the resulting green slurry is stirred at room temp for 90 minutes. The reaction mixture is poured onto water (200 ml) and the resultant precipitate filtered and washed with water. This yellow solid is then suspended in 2N HCl (200 ml) and stirred for 1 hour, then filtered, washed with water and hexane and dried in vacuo to give 4-bromo-2-methyl-thiobenzamide (820 mg).