Hydrochloric Acid → Methyl 2-(chlorosulfonyl)-6-methylbenzoate

関与物質

反応条件

反応手順

The methyl 6-methylanthranilate so prepared (4.23 g, 0.026 mol) was dissolved in 25 ml of acetic acid and the solution cooled to 0° C. Concentrated hydrochloric acid (45 ml) was added to produce a tan slurry. A solution of 1.89 g (0.027 mol) of sodium nitrite in 8 ml water was added dropwise with stirring, the resulting orange solution was stirred at 0° C. for 1 hour and then added in 6 portions to a mixture of 2.18 g (0.013 mol) of cuptic chloride dihydrate and sulfur dioxide (6.3 g) in 33 ml of acetic acid and 6 ml of water at 0° C. The dark green solution was stirred at room temperature overnight, poured into 300 ml of ice-water, and the solid which separated was collected and dried by suction to provide 1.11 g of methyl 2-chlorosulfonyl-6-methylbenzoate which was immediately added to 100 ml of ice cold ammonium hydroxide and stirred at room temperature overnight. The solution was acidified to pH 1 with concentrated hydrochloric acid, and the resulting precipitate was collected and air-dried to provide 729 mg (12%) of 4-methylsaccharin, mp 224°-226° C.

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