반응 #57965

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2-bromo-4-[({[(1E)-(4-tert-butylphenyl)methylidene]amino}oxy)methyl]benzoic acid methyl ester

sodium hydroxide

→

2-bromo-4-[({[(1E)-(4-tert-butylphenyl)methylidene]amino}oxy)methyl]benzoic acid

수율 94.0%

용매

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후처리

1. 1
   온도This mixture was heated
2. 2
   온도to reflux for 3 hours
3. 3
   농축The mixture was concentrated to approximately ¼ volume
4. 4
   기타partitioned between ethyl acetate and brine
5. 5
   기타The layers were then separated
6. 6
   추출The aqueous layer was extracted with one additional portion of ethyl acetate
7. 7
   건조dried over anhydrous magnesium sulfate
8. 8
   여과filtered
9. 9
   농축concentrated under reduced pressure
10. 10
    workup.DISSOLUTIONThe crude material was dissolved in hot methylene chloride
11. 11
    기타crystallized out by the addition of room temperature hexanes (60 mL)

실험 절차

To a solution of 2-bromo-4-[({[(1E)-(4-tert-butylphenyl)methylidene]amino}oxy)methyl]benzoic acid methyl ester (0.43 g, 1.07 mmol), in 10/5/3 tetrahydrofuran/ethanol/water (24 mL) was added 2.5 M sodium hydroxide solution (4 mL). This mixture was heated to reflux for 3 hours and then allowed to cool back to room temperature. The mixture was concentrated to approximately ¼ volume and partitioned between ethyl acetate and brine. The aqueous layer was acidified to approximately pH 1 using 1 N hydrochloric acid. The layers were then separated. The aqueous layer was extracted with one additional portion of ethyl acetate. The organics were combined, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The crude material was dissolved in hot methylene chloride and crystallized out by the addition of room temperature hexanes (60 mL), and allowing the mixture to sit for 2 hours to give 2-bromo-4-[({[(1E)-(4-tert-butylphenyl)methylidene]amino}oxy)methyl]benzoic acid (0.39 g, 94%) as a white solid. mp=162-163° C. 1H NMR (500 MHz, DMSO-d6); δ 13.35 (bs, 1H), 8.31 (s, 1H), 7.74 (d, 1H), 7.71 (s, 1H), 7.52 (d, 2H), 7.46 (d, 1H), 7.42 (d, 2H), 5.19 (s, 2H), 1.26 (s, 9H). Mass spec (MW 390.28); (ES+) m/z 390.0, (ES−) m/z 388.3. Elemental analysis; Calculated for C19H20BrNO3: C, 58.47; H, 5.17; N, 3.59. Found: C, 57.99; H, 5.03; N, 3.41.

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