Hydrogen Bromide → 3-Bromo-4-chlorothiophene

HRID 2372662

Reaktionsgleichung

Reaktionsgleichung von HRID 2372662
O.O.C([O-])(=O)C.[Pb+2].C([O-])(=O)C.Br.[Cl:13][C:14]1[C:18]([Br:19])=[C:17](Br)[S:16][C:15]=1Br.BrC1C=CSC=1Br>F[B-](F)(F)F.C([N+](CCCC)(CCCC)CCCC)CCC.CO>[Br:19][C:18]1[C:14]([Cl:13])=[CH:15][S:16][CH:17]=1.[Cl:13][C:14]1[CH:18]=[CH:17][S:16][CH:15]=1

Komponenten

8

Edukt 4

HCID 260Hydrogen BromideHCID 765902,3-DibromothiopheneHCID 148351733-Chloro-2,4,5-tribromothiopheneHCID 86745588Lead(2+);diacetate;dihydrate

Produkt 2

HCID 870173-ChlorothiopheneAusbeute 9,1 %HCID 123565123-Bromo-4-chlorothiopheneAusbeute 73,8 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 67932Tetrabutylammonium TetrafluoroborateKatalysatorHCID 887MethanolLösungsmittel

Versuchsvorschrift

A catholyte of 650 ml of methanol, 0.5 g of lead acetate dihydrate, 0.5 g of tetrabutylammonium tetrafluoroborate, 20 ml of hydrogen bromide solution (48% in water) and 20 g of 3-chloro-2,4,5-tribromothiophene were electrolysed in electrolysis cell 1 at a current density of 100 mA/cm2 at the beginning and 25 mA/cm2 at the end of the batch, a voltage of 7.2 to 3.4 V and a temperature of 28° to 35° C. The current consumption was 8.8 Ah. After addition of 100 ml of water to the catholyte, extraction with CF2Cl--CFCl2 and removal of the solvent by distillation, 8.24 g of 4-bromo-3-chlorothiophene (yield: 73.8%), 0.665 g of 3-chlorothiophene (yield: 9.1%) and 0.4 g of dibromothiophene of unknown structure (yield: 2.9%) were obtained.

Aufarbeitung

  1. customa temperature of 28° to 35° C
  2. customThe current consumption
  3. additionAfter addition of 100 ml of water
  4. extractionto the catholyte, extraction
  5. customwith CF2Cl--CFCl2 and removal of the solvent

Quellen und Nachweise

ORD-Eintrag
ord-cc34696dc5034aeabcf169cfefdef023
Quelldatensatz
uspto-grants-1992_03
Patentnummer
US05100520

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