Carbon tetrabromide → 3-(2,2-Dibromoethenyl)-2,5-dimethoxytetrahydrofuran

HRID 613866

반응식

HRID 613866 반응식
C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[C:20]([Br:24])(Br)(Br)[Br:21].[CH3:25][O:26][CH:27]1[CH:31]([CH:32]=O)[CH2:30][CH:29]([O:34][CH3:35])[O:28]1>C(Cl)Cl.[Zn]>[Br:21][C:20]([Br:24])=[CH:32][CH:31]1[CH2:30][CH:29]([O:34][CH3:35])[O:28][CH:27]1[O:26][CH3:25]

참가 물질

6

반응물 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 567310Tetrahydro-2,5-dimethoxyfuran-3-carbaldehyde

생성물 1

HCID 183804243-(2,2-Dibromoethenyl)-2,5-dimethoxytetrahydrofuran수율 55.2%

시약·촉매·용매 2

HCID 23994Zinc촉매HCID 6344Dichloromethane용매

실험 절차

A mixture of Zn powder (1.65 g, 25.0 mmol), triphenylphosphine (6.54 g, 25.0 mmol), and CBr4 (8.30 g, 25.0 mmol) in dry CH2Cl2 (40 mL) was stirred at ambient temperature. After 24 hours, 2,5-dimethoxy-tetrahydrofuran-3-carboxaldehyde (2.00 g, 12.5 mmol) was added and an exothermic reaction ensued. After 30 minutes, pet ether (100 mL) was added and the resultant upper layer separated. The lower layer was twice diluted with CH2Cl2 (50 mL) and pet ether (50 mL), and the upper layer reserved. The combined upper layers were combined, passed through a pad of SiO2, and concentrated under reduced pressure at 30° C. or below to give 2.18 g (55%) of 3-(2,2-dibromoethenyl)-2,5-dimethoxytetrahydrofuran as a volatile colorless oil, which was a mixture of diastreomers by 1H NMR and used immediately without further purification.

후처리

  1. customan exothermic reaction
  2. waitAfter 30 minutes
  3. customthe resultant upper layer separated
  4. additionThe lower layer was twice diluted with CH2Cl2 (50 mL) and pet ether (50 mL)
  5. concentrationconcentrated under reduced pressure at 30° C. or below

출처 및 근거

ORD 기록
ord-70ff169213d541b0ba03153e63bc0a69
출처 데이터셋
uspto-grants-1999_12
특허 번호
US06008243

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