Dimethyl Sulfate → Methyl 2-methoxy-3-methylbenzoate

Beteiligte Stoffe

Reaktionsschritte

To a mixture of 3-methyl-salicylic acid (200 g, 1.32 mol), anhydrous potassium carbonate (500 gram, 3.6 mol) and dry acetone (3.5 L) in a 5 liter round bottle flask, dimethylsulfate (DMS, 210 mL, 2.2 mol) was added in several portions. After stirring at room temperature overnight, the mixture was heated at reflux, and the reaction was monitored by TLC. In order to complete the etherification, further additions of DMS and K2CO3 may be necessary. When TLC indicated the completion of the reaction, the mixture was refluxed 4 more hours to destroy any remaining DMS. The mixture was filtered, and the filtrate was evaporated to remove the solvents. A pale yellow thick oil was obtained as the raw product, yield 215 g (91%). 1H NMR (500 MHz, CDCl3, 25° C.) δ: 2.26 (s, 3H, CH3), 3.78 (s, 3H, OCH3), 3.85 (s, 3H, OCH3), 6.98 (t, J=7.5, 1H, ArH), 7.27 (d, J=7.5, 1H, ArH), 7.58 (d, J=7.5, 1H, ArH); 13C NMR (500 MHz, CDCl3, 25° C.) δ: 15.7, 51.8, 61.1, 123.2, 124.3, 128.8, 132.4, 134.8, 158.1, 166.6.

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