Bromine → Methyl 4-bromo-3-hydroxythiophene-2-carboxylate

HRID 479283

Reaktionsgleichung

Reaktionsgleichung von HRID 479283
[OH:1][C:2]1[CH:6]=[CH:5][S:4][C:3]=1[C:7]([O:9][CH3:10])=[O:8].[Br:11]Br.OS([O-])=O.[Na+]>C(O)(=O)C>[Br:11][C:6]1[C:2]([OH:1])=[C:3]([C:7]([O:9][CH3:10])=[O:8])[S:4][CH:5]=1

Komponenten

5

Edukt 3

HCID 24408Bromine2×HCID 5811273-Hydroxy-thiophene-2-carboxylic acid methyl esterHCID 23665763Sodium Bisulfite

Produkt 1

HCID 2777611Methyl 4-bromo-3-hydroxythiophene-2-carboxylate

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 176Acetic AcidLösungsmittel

Versuchsvorschrift

To a solution of 31 g (0.2 mole) of methyl 3-hydroxy-2-thiophenecarboxylate in 400 milliliters (mL) of glacial acetic acid was added 31.3 g (0.2 mole) of Br2 over 45 minutes (min). After 16 hours (hr), another 31.3 g of Br2 was added over 6 hr and the reaction was stirred another 18 hr. The reaction mixture was poured into aqueous NaHSO3 and extracted with ether. The organic phase was separated, washed with water (2×300 mL), dried over MgSO4, filtered and concentrated to a viscous oil. This oil (47 g) was dissolved in 200 mL of methanol and after 48 hr at 15° C., 36 g (77%) of light pink crystals were collected by filtration. mp 79-80° C. 1H NMR (300 MHz, CDCl3): δ 9.8 (br, 1H); 7.4 (s, 1H); 3.9 (s, 3H). Anal. Calc'd for C6H5BrO3S: C, 30.04; H, 2.23; S, 13.52. Found: C, 30.04; H, 1.92; S, 14.01.

Aufarbeitung

  1. extractionextracted with ether
  2. customThe organic phase was separated
  3. washwashed with water (2×300 mL)
  4. dry with materialdried over MgSO4
  5. filtrationfiltered
  6. concentrationconcentrated to a viscous oil
  7. dissolutionThis oil (47 g) was dissolved in 200 mL of methanol and after 48 hr at 15° C.
  8. filtration36 g (77%) of light pink crystals were collected by filtration

Quellen und Nachweise

ORD-Eintrag
ord-d0310371bc0d45818d3a2ea59d1f2fe9
Quelldatensatz
uspto-grants-2003_11
Patentnummer
US06645918B1

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