反应详情

To a solution of methyl 2-bromobenzoate (20.76 g, 96 mmol) in 120 mL of anhydrous ether under Argon at 0° C. was slowly added methylmagnesium bromide (77 mL, 3.26 M) at a rate that the internal temperature of the mixture was below 20° C. A white suspension resulted, and the mixture was stirred at room temperature for 2 h. The mixture was cooled in an ice-water bath. To the reaction mixture was very slowly added hydrochloric acid (400 mL, 0.5 M). The pH of the final mixture was adjusted to less than about 6 with few drops of 2M hydrochloric acid. The layers were separated, and the aqueous layer was extracted twice with ether. The organic layers were combined and dried over magnesium sulfate. The organic fraction was filtered, and the filtrate was concentrated to yield the title compound as a pale yellow liquid, which was distilled under vacuum to afford the title Compound 10d as a colorless liquid (16.9 g, 82%, b.p. about 65-70° C./0.3 mmHg). 1H NMR (400 MHz, CDCl3) δ (ppm): 7.67 (dd, 1H, J=1.7, 7.9 Hz), 7.58 (dd, 1H, J=1.3, 7.9 Hz), 7.30 (ddd, 1H, J=1.4, 7.4, 7.9 Hz), 7.10 (ddd, 1H, J=1.7, 7.4, 7.8 Hz), 2.77 (br s, 1H), 1.76 (s, 6H).

1. customat 0° C.
2. customwas below 20° C
3. customA white suspension resulted
4. temperatureThe mixture was cooled in an ice-water bath
5. customThe layers were separated
6. extractionthe aqueous layer was extracted twice with ether
7. dry with materialdried over magnesium sulfate
8. filtrationThe organic fraction was filtered
9. concentrationthe filtrate was concentrated