Sodium Nitrite → 6-Chlorobenzofuro[2,3-b]pyridine

HRID 1514012ノート

反応式

HRID 1514012 の反応式
[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([O:15]C)=[C:6]([C:8]2[C:9](N)=[N:10][CH:11]=[CH:12][CH:13]=2)[CH:7]=1.N([O-])=O.[Na+]>C1COCC1.[H+].[B-](F)(F)(F)F.O>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]2[O:15][C:9]3=[N:10][CH:11]=[CH:12][CH:13]=[C:8]3[C:6]=2[CH:7]=1

参加物

6

反応物 2

HCID 23668193Sodium NitriteHCID 640879063-(5-Chloro-2-methoxyphenyl)pyridin-2-amine

生成物 1

HCID 123753316-Chlorobenzofuro[2,3-b]pyridine収率 35.5%

試薬・触媒・溶媒 3

HCID 962Water溶媒HCID 8028Tetrahydrofuran溶媒HCID 28118Tetrafluoroboric acid溶媒

反応条件

温度
-5 °C

実験手順

3-(5-Chloro-2-methoxyphenyl)pyridin-2-amine (5.00 g, 21 mmol) was dissolved in the mixture of THF (409 mL), HBF4 (50% aqueous solution, 36 mL) and 15 mL of water. The solution was cooled to −5° C., and sodium nitrite (1.70 g in 20 mL of water) was added dropwise. Reaction was kept 1 hour at −5° C., then was allowed to warm up to room temperature and stirred overnight at room temperature. Then pH of the reaction mixture was adjusted to 10, and it was extracted with ethyl acetate (4×25 mL). Organic fractions were combined, dried over sodium sulfate and evaporated. The residue was subjected to column chromatography on silica gel, eluent hexane/ethyl acetate 9/1 mixture. Chromatography product contained 3-(5-chloro-2-methoxyphenyl)-2-fluoropyridine, pure 6-chlorobenzofuro[2,3-b]pyridine (1.52 g, colorless long needles) was obtained by crystallization from hexane/ethyl acetate.

後処理

  1. customReaction
  2. temperatureto warm up to room temperature
  3. extractionwas extracted with ethyl acetate (4×25 mL)
  4. dry with materialdried over sodium sulfate
  5. customevaporated

出典と根拠

ORDレコード
ord-39b1359470e94c6bbfb3d9c35d8de048
出典データセット
uspto-grants-2012_07
特許番号
US08221905B2

反応ノート

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