Trimethyl orthoformate → 6-Bromo-5-chlorobenzoxazole

HRID 2272175ノート

反応式

HRID 2272175 の反応式
[NH2:1][C:2]1[CH:7]=[C:6]([Cl:8])[C:5]([Br:9])=[CH:4][C:3]=1[OH:10].[Yb+3].F[C:13](F)(F)S([O-])(=O)=O.FC(F)(F)S([O-])(=O)=O.FC(F)(F)S([O-])(=O)=O.C(OC)(OC)OC>CCO.CC(=O)OCC.CCCCCC>[Br:9][C:5]1[C:6]([Cl:8])=[CH:7][C:2]2[N:1]=[CH:13][O:10][C:3]=2[CH:4]=1

参加物

7

反応物 3

HCID 9005Trimethyl orthoformateHCID 2733225Ytterbium triflateHCID 584871002-Amino-5-bromo-4-chlorophenol

生成物 1

HCID 584872776-Bromo-5-chlorobenzoxazole収率 6,559.2%

試薬・触媒・溶媒 3

HCID 702Ethanol溶媒HCID 8058Hexane溶媒HCID 8857Ethyl Acetate溶媒2 回

反応条件

温度
90 °C

実験手順

A mixture of 2-amino-5-bromo-4-chlorophenol (29) (865 mg, 3.89 mmol), trifluoromethanesulfonic acid Ytterbium (III) salt (24 mg, 1% mol) and trimethyl orthoformate (511 μl, 1.2 eq.) in 2 ml EtOH was heated at 90° C. for 2 h. After cooling down to r.t., the reaction mixture was taken up in EA, washed with aq. NaHCO3 and brine, dried over Na2SO4, concentrated to dryness. The resulting brown solid was dissolved in DCM and subjected to silica gel column purification using 0-100% B (A: hexane; B: 50% EA in hexane) to furnish 590 mg 30 as yellow solid (yield: 65.2%).

後処理

  1. temperatureAfter cooling down to r.t.
  2. washwashed with aq. NaHCO3 and brine
  3. dry with materialdried over Na2SO4
  4. concentrationconcentrated to dryness
  5. dissolutionThe resulting brown solid was dissolved in DCM
  6. customsubjected to silica gel column purification

出典と根拠

ORDレコード
ord-d882ecca016b49c0add45a0487e3ce82
出典データセット
uspto-grants-2015_09
特許番号
US09120751B2

反応ノート

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