反应详情

Referring to FIG. 37, to a solution of ethyl 2-(3,5-dimethylphenoxy)acetate (19 g, obtained from the previous step) in methanol (150 mL) was added NaOH solution (6 N, 50 mL). The reaction mixture was stirred at room temperature for 4 h and then adjusted to pH=1˜2 with 2 N HCl solution. The resulting mixture was extracted with ethyl acetate (150 mL×2). The combined extracts were washed with brine, dried over anhydrous Na2SO4 and concentrated under reduced pressure to give a solid, which was washed with ethyl acetate/hexane (1:15, 40 mL) to give product (14 g, 95% yield over two steps); 1H NMR (CDCl3, 300 MHz): δ 6.69 (s, 1H), 6.58 (s, 2H), 4.68 (s, 2H). 2.31 (s, 6H).

1. extractionThe resulting mixture was extracted with ethyl acetate (150 mL×2)
2. washThe combined extracts were washed with brine
3. dry with materialdried over anhydrous Na2SO4
4. concentrationconcentrated under reduced pressure
5. customto give a solid, which
6. washwas washed with ethyl acetate/hexane (1:15, 40 mL)
7. customto give product (14 g, 95% yield over two steps)