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

HRID 650670

Reaktionsgleichung

Reaktionsgleichung von HRID 650670
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]

Komponenten

5

Edukt 3

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

Produkt 1

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

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 5943Carbon TetrachlorideLösungsmittel

Versuchsvorschrift

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).

Aufarbeitung

  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)

Quellen und Nachweise

ORD-Eintrag
ord-b123d0dea85948b8834e85b7e638c417
Quelldatensatz
uspto-grants-2001_08
Patentnummer
US06274620B1

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