Ethyl 5-amino-2-methylbenzoate → Ethyl 5-hydroxy-2-methylbenzoate

HRID 1640024Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1640024
N[C:2]1[CH:3]=[CH:4][C:5]([CH3:13])=[C:6]([CH:12]=1)[C:7]([O:9][CH2:10][CH3:11])=[O:8].N([O-])=[O:15].[Na+]>S(=O)(=O)(O)O.O.C(OCC)(=O)C>[OH:15][C:2]1[CH:3]=[CH:4][C:5]([CH3:13])=[C:6]([CH:12]=1)[C:7]([O:9][CH2:10][CH3:11])=[O:8]

Komponenten

6

Edukt 2

HCID 18690998Ethyl 5-amino-2-methylbenzoateHCID 23668193Sodium Nitrite

Produkt 1

HCID 15730468Ethyl 5-hydroxy-2-methylbenzoateAusbeute 86,2 %

Reagenzien, Katalysatoren, Lösungsmittel 3

HCID 962WaterLösungsmittelHCID 1118Sulfuric AcidLösungsmittelHCID 8857Ethyl AcetateLösungsmittel

Reaktionsbedingungen

Temperatur
0 °C

Versuchsvorschrift

A mixture of ethyl 5-amino-2-methylbenzoate (14.4 g, 80.3 mmol) in aqueous 5% sulfuric acid (300 mL) was cooled with an ice-bath for 15 min. Sodium nitrite (6.09 g, 88.3 mmol) was then added dropwise as a solution in water (50 mL), and the resulting mixture stirred for at 0° C. for 30 min. After this time, the resulting mixture was heated to 60° C. for 18 h. The reaction mixture was then cooled to room temperature and diluted with ethyl acetate (150 mL). The organic layer was separated, dried over sodium sulfate, filtered, and concentrated under reduced pressure. Purification by flash chromatography (silica, gradient 0-40%, hexanes/ethyl acetate) afforded 12.48 g (86%) of ethyl 5-hydroxy-2-methylbenzoate as red-brown solid: 1H NMR (300 MHz, CDCl3) δ 7.44 (d, J=2.8 Hz, 1H), 7.10 (d, J=8.3 Hz, 1H), 6.91 (dd, J=8.3, 2.8 Hz, 1H), 5.44 (s, 1H), 4.35 (q, J=7.1 Hz, 2H), 2.50 (s, 3H), 1.38 (t, J=7.1 Hz, 3H); ESI MS m/z 181 [M+H]+.

Aufarbeitung

  1. temperaturewas cooled with an ice-bath for 15 min
  2. temperatureAfter this time, the resulting mixture was heated to 60° C. for 18 h
  3. temperatureThe reaction mixture was then cooled to room temperature
  4. customThe organic layer was separated
  5. dry with materialdried over sodium sulfate
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. customPurification by flash chromatography (silica, gradient 0-40%, hexanes/ethyl acetate)

Quellen und Nachweise

ORD-Eintrag
ord-71ac9c2794b646c599403fac490a8a24
Quelldatensatz
uspto-grants-2012_02
Patentnummer
US08110681B2

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