3,4,5-Trimethoxybenzaldehyde → 2-Bromo-3,4,5-trimethoxybenzaldehyde

HRID 1925086Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1925086
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:8]=[C:9]([O:13][CH3:14])[C:10]=1[O:11][CH3:12])[CH:6]=[O:7].[Br:15]Br>O.C(Cl)(Cl)Cl>[Br:15][C:8]1[C:9]([O:13][CH3:14])=[C:10]([O:11][CH3:12])[C:3]([O:2][CH3:1])=[CH:4][C:5]=1[CH:6]=[O:7]

Komponenten

5

Edukt 2

HCID 68583,4,5-TrimethoxybenzaldehydeHCID 24408Bromine

Produkt 1

HCID 7780032-Bromo-3,4,5-trimethoxybenzaldehydeAusbeute 98,2 %

Reagenzien, Katalysatoren, Lösungsmittel 2

HCID 962WaterLösungsmittelHCID 6212ChloroformLösungsmittel2×

Versuchsvorschrift

To a stirred refluxing solution of 3,4,5-trimethoxybenzaldehyde (17.0 g, 86.6 mmol) in water (3 mL) and chloroform (100 mL) was added a solution of bromine (14.7 g, 92 mmol) in chloroform (30 mL) dropwise. The solution was heated under reflux overnight, cooled, washed with water (2×100 mL) and saturated aqueous sodium hydrogen carbonate (50 mL), dried over MgSO4, filtered and evaporated. The residual orange oil (27 g) crystallised on standing. The solid was washed with petroleum ether, b.p. 40-60° C., to obtain 2-bromo-3,4,5-trimethoxybenzaldehyde as white crystals (23.4 g, 98%); m.p. 69° C. (literature value 69.5-71° C., see Brown, E.; Robin, J.-P.; Dhal, R. Tetrahedron 1982, 38, 2569-2579); NMR Spectrum δH (300 MHz, CDCl3) 10.40 (1H, s, 1-CHO), 7.29 (1H, s, 6-H), 4.00 (3H, s, OCH3), 3.95 (3H, s, OCH3) and 3.93 (3H, s, OCH3); NMR Spectrum δC (75 MHz, CDCl3) 56.6, 61.6, 106.9, 126.1, 128.1, 149.2, 150.3, 152.8, 189.2; νmax/cm−1 (thin film) 2940, 2843, 1685 (C═O), 1588, 1480, 1460, 1386, 1317, 1196, 1161, 1134, 1103 and 1002 (data in accordance with published values, see Brown, E.; Robin, J.-P.; Dhal, R. Tetrahedron 1982, 38, 2569-2579); Rf(hexane-ethyl acetate 4:1) 0.50.

Aufarbeitung

  1. temperatureThe solution was heated
  2. temperatureunder reflux overnight
  3. temperaturecooled
  4. washwashed with water (2×100 mL) and saturated aqueous sodium hydrogen carbonate (50 mL)
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. customevaporated
  8. customThe residual orange oil (27 g) crystallised
  9. washThe solid was washed with petroleum ether, b.p. 40-60° C.

Quellen und Nachweise

ORD-Eintrag
ord-345e002eff6d4d6ca421ee66ba9e093a
Quelldatensatz
uspto-grants-2012_05
Patentnummer
US08178578B2

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