Boron tribromide → HCID 13564460、化合物
反応式
C[O:2][C:3]1[C:12]([CH:13]=[O:14])=[C:7]2[CH2:8][CH2:9][CH2:10][O:11][C:6]2=[CH:5][CH:4]=1.B(Br)(Br)Br>C(Cl)Cl>[OH:2][C:3]1[C:12]([CH:13]=[O:14])=[C:7]2[CH2:8][CH2:9][CH2:10][O:11][C:6]2=[CH:5][CH:4]=1参加物
実験手順
A solution of 6-methoxy-3,4-dihydrobenzopyran-5-carboxaldehyde (30.00 g, 156 mmol) in dry methylene chloride (625 mL) was cooled to an internal temperature of -67°. A solution of boron tribromide (1M in methylene chloride, 67.5 mL, 67.5 mmol) was added dropwise. The cooling bath was removed and the mixture allowed to stir under nitrogen for three hours. The reaction was then quenched by the dropwise addition of methanol (75 mL) and the resulting mixture poured into satureated aqueous sodium chloride (1200 mL). The layers were separated and the organic extract washed with saturated sodium chloride (600 mL), dried (Na2SO4) and concentrated. Purification by preparative HPLC (Waters Prep 500, 9:1 hexane: ethyl acetate as eluant) afforded 6-hydroxy-3,4-dihydrobenzopyran-5 -carboxaldehyde (22.46 g, 80.8%), m.p. 93-95.
後処理
- customThe cooling bath was removed
- customThe reaction was then quenched by the dropwise addition of methanol (75 mL)
- additionthe resulting mixture poured into satureated aqueous sodium chloride (1200 mL)
- customThe layers were separated
- extractionthe organic extract
- washwashed with saturated sodium chloride (600 mL)
- dry with materialdried (Na2SO4)
- concentrationconcentrated
- customPurification by preparative HPLC (Waters Prep 500, 9:1 hexane: ethyl acetate as eluant)
出典と根拠
- ORDレコード
- ord-95def54f95774bc49e15570fb2ceeccb
- 出典データセット
- uspto-grants-1986_01
- 特許番号
- US04563476
反応ノート
読み込み中…