Application of 14920-81-1, In the next few decades, the world population will flourish. As the population grows rapidly and people all over the world use more and more resources, all industries must consider their environmental impact. 14920-81-1, name is Methyl 2,6-dimethylbenzoate belongs to esters-buliding-blocks compound, it is a common compound, a new synthetic route is introduced below.
To a solution of methyl 2,6-dimethylbenzoate (described in J. Am. Chem. Soc., 99, 6405 (1977); 23.4 g, 143 mmol) in dichloroethane (200 ml) were added N-bromosuccinimide (25.46 g, 143 mmol) and alpha,alpha’-azobisisobutyronitrile (234.8 mg, 1.43 mmol), and the mixture was irradiated with visible light (tungsten lamp, 375 W) for 1 hour. After cooling the reaction mixture, the precipitated material was filtered off, and the solvent was distilled off under reduced pressure. The obtained oily residue was subjected to chromatography on a silica gel (200 g) column (eluent; ethyl acetate : hexane = 1 : 10) to give an oily mixture containing ca. 50% methyl 2-(bromomethyl)-6-methylbenzoate. The mixture was dissolved in dimethyl sulfoxide (150 ml), and sodium acetate (16.4 g, 0.2 mol) was added thereto. The resulting mixture was stirred at room temperature for 2 hours, then a saturated aqueous solution of ammonium chloride was added thereto, and the product was extracted with ethyl acetate. The organic layer was washed with a saturated aqueous solution of sodium chloride, and the solvent was distilled off under reduced pressure to give an oily residue. The residue was subjected to chromatography on a silica gel (200 g) column (eluent; ethyl acetate : hexane = 1 : 10 ~ 1 : 3) to give methyl 2-(acetoxymethyl)-6-methylbenzoate (8.09 g, more than 80% content) as a colorless oil. The obtained methyl 2-(acetoxymethyl)-6-methylbenzoate was used for the following reaction without further purification. NMR spectrum (400 MHz, CDCl3) delta ppm: 2.07 (3H, s), 2.38 (3H, s), 3.92 (3H, s), 5.15 (2H, s), 6.99-7.12 (3H, m). Methyl 2-(acetoxymethyl)-6-methylbenzoate obtained above was dissolved in methanol (80 ml), and potassium carbonate (251.5 mg, 1.8 mmol) was added thereto. The mixture was stirred at room temperature for 2 hours, then a 2N aqueous solution of hydrochloric acid (3 ml) was added thereto, and the solvent was distilled off under reduced pressure. The obtained solid residue was dissolved in ethyl acetate, and the solution was washed with a saturated aqueous solution of sodium chloride and then the solvent was distilled off under reduced pressure. The solid residue was subjected to chromatography on a silica gel (100 g) column (eluent; ethyl acetate : hexane = 1 : 2) to afford 7-methyl-1(3H)-isobenzofuranone (5.18 g, more than 80% content). The obtained 7-methyl-1(3H)-isobenzofuranone was used for the following reaction without further purification. NMR spectrum (400 MHz, CDCl3) delta ppm: 2.71 (3H, s), 5.23 (2H, s), 7.25-7.30 (2H, m), 7.56 (1H, t, J=8 Hz). A solution of the 7-methyl-1(3H)-isobenzofuranone obtained above in tetrahydrofuran (80 ml) was cooled to 0C, and lithium borohydride (1.90 g, 87.2 mmol) was added thereto. The mixture was stirred at 60C for 2 hours, then cooled to 0C, and a 2N aqueous solution of hydrochloric acid (50 ml) was added dropwise. The product was extracted with ethyl acetate, and the solvent was evaporated under reduced pressure to give an oily residue. The residue was subjected to chromatography on a silica gel (75 g) column (eluent; ethyl acetate : hexane = 2 : 1 ? 1 : 0) to afford the title compound (4.17 g, 19% total yield from methyl 2,6-dimethylbenzoate) as an oil. NMR spectrum (400 MHz, CDCl3) delta ppm: 2.45 (3H, s), 4.76 (2H, s), 4.79 (2H, s), 7.17-7.22 (3H, m) IR spectrum nu max CHCl3 cm-1: 3605, 1469, 1380, 1002 Mass spectrum m/z (EI): 152 (M+).
The synthetic route of Methyl 2,6-dimethylbenzoate has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Sankyo Company, Limited; EP1362856; (2003); A1;,
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