Trimethyl borate → 2,3-Dihydro-3-hydroxy2,2-dimethylbenzofuran-7-ylboronic acid

HRID 440911노트

반응식

HRID 440911 반응식
C([O:4][CH:5]1[C:9]2[CH:10]=[CH:11][CH:12]=[C:13](Br)[C:8]=2[O:7][C:6]1([CH3:16])[CH3:15])(=O)C.C([Li])CCC.[B:22](OC)([O:25]C)[O:23]C>O1CCCC1>[OH:4][CH:5]1[C:9]2[CH:10]=[CH:11][CH:12]=[C:13]([B:22]([OH:25])[OH:23])[C:8]=2[O:7][C:6]1([CH3:16])[CH3:15]

참가 물질

5

반응물 3

HCID 8470Trimethyl borateHCID 190407903-Acetoxy-7-bromo-2,3-dihydro-2,2-dimethylbenzofuranHCID 178418339Butyllithium

생성물 1

HCID 190407762,3-Dihydro-3-hydroxy2,2-dimethylbenzofuran-7-ylboronic acid

시약·촉매·용매 1

HCID 8028Tetrahydrofuran용매

반응 조건

온도
-80 °C

실험 절차

A stirring solution of 5.7 grams (0,020 mole) of 3-acetoxy-7-bromo-2,3-dihydro-2,2-dimethylbenzofuran in 150 mL of tetrahydrofuran is cooled to -80° C., and 18.2 mL of n-butyllithium in hexanes (2.5 Molar-0.046 mole) is added dropwise during a 15 minute period, while maintaining the reaction mixture temperature at about -80° C. Upon completion of the addition, the reaction mixture is stirred at -80° C. for 15 minutes. After this time, 6.9 mL (0.061 mole) of trimethyl borate is added during a 1 minute period. The reaction mixture is then allowed to warm slowly to ambient temperature during a 3 hour period, where it is stirred for an additional 1 hour. After this time, the reaction mixture is concentrated under reduced pressure to a volume of about 50 mL. The concentrate is then poured into 500 mL of ice-water. The mixture is then made acidic with about 26 mL of aqueous 2N hydrochloric acid. The mixture is filtered, yielding 2,3-dihydro-3-hydroxy-2,2-dimethylbenzofuran-7-ylboronic acid.

후처리

  1. additionUpon completion of the addition
  2. temperatureto warm slowly to ambient temperature during a 3 hour period
  3. stirringwhere it is stirred for an additional 1 hour
  4. concentrationAfter this time, the reaction mixture is concentrated under reduced pressure to a volume of about 50 mL
  5. additionThe concentrate is then poured into 500 mL of ice-water
  6. filtrationThe mixture is filtered

출처 및 근거

ORD 기록
ord-c1b9424aa3a24c898ed4a6b53056e275
출처 데이터셋
uspto-grants-1996_05
특허 번호
US05521190

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