N-bromobutanimide → Methyl 5-(bromomethyl)thiophene-2-carboxylate

HRID 650670

反応式

HRID 650670 の反応式
COC(C1SC(C)=CC=1)=O.BrN1C(=O)CCC1=O.[CH3:19][O:20][C:21]([C:23]1[S:24][C:25]([CH:28](Br)[Br:29])=[CH:26][CH:27]=1)=[O:22]>C(Cl)(Cl)(Cl)Cl>[CH3:19][O:20][C:21]([C:23]1[S:24][C:25]([CH2:28][Br:29])=[CH:26][CH:27]=1)=[O:22]

参加物

5

反応物 3

HCID 67184N-bromobutanimideHCID 580756Methyl 5-methyl-2-thiophenecarboxylateHCID 24179893Methyl 5-(dibromomethyl)thiophene-2-carboxylate

生成物 1

HCID 11424851Methyl 5-(bromomethyl)thiophene-2-carboxylate収率 25%

試薬・触媒・溶媒 1

HCID 5943Carbon Tetrachloride溶媒

実験手順

5-Methyl-thiophene-2-carboxylic acid methyl ester (20.0 g, 0.13 mol) was dissolved in a suspension of N-bromosuccinimide (45.4 g, 0.26 mol) and 2,2′-aza-bis-isobutyronitrile (0.1 g, 0.61 mmol) in 1 L of carbon tetrachloride. The suspension was refluxed for 48 hours then cooled and the precipitate was filtered off. The filtrate was concentrated and the residue was purified on silica gel (100% hexanes then 9:1 Hexanes-Ethyl acetate) to provide a 26 g fraction containing mainly the di-brominated compound 5-dibromomethyl-thiophene-2-carboxylic acid methyl ester as a yellow oil and a more polar fraction (7.5 g) containing mainly compound T-1 (25% yield) as a yellow oil (70% purity).

後処理

  1. temperatureThe suspension was refluxed for 48 hours
  2. temperaturethen cooled
  3. filtrationthe precipitate was filtered off
  4. concentrationThe filtrate was concentrated
  5. customthe residue was purified on silica gel (100% hexanes
  6. custom9:1 Hexanes-Ethyl acetate) to provide a 26 g fraction
  7. additiona more polar fraction (7.5 g) containing mainly compound T-1 (25% yield) as a yellow oil (70% purity)

出典と根拠

ORDレコード
ord-b123d0dea85948b8834e85b7e638c417
出典データセット
uspto-grants-2001_08
特許番号
US06274620B1

関連ノート

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