Lithium Hydroxide → 5-Bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid

HRID 661678Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 661678
C(OC(CCC[O:11][C:12](=[O:32])[C:13]1[CH:18]=[C:17]([Br:19])[C:16]([Cl:20])=[CH:15][C:14]=1[O:21][CH2:22][CH2:23][CH2:24][C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26])=O)(C)(C)C.[Li+].[OH-].OS([O-])(=O)=O.[Na+]>C1COCC1>[Br:19][C:17]1[C:16]([Cl:20])=[CH:15][C:14]([O:21][CH2:22][CH2:23][CH2:24][C:25]([O:27][C:28]([CH3:30])([CH3:29])[CH3:31])=[O:26])=[C:13]([CH:18]=1)[C:12]([OH:32])=[O:11]

Komponenten

5

Edukt 3

HCID 3939Lithium HydroxideHCID 516919Sodium BisulfateHCID 686035915-Bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid 3-tert-butoxycarbonyl-propyl ester

Produkt 1

HCID 686032665-Bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acidAusbeute 41,5 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8028TetrahydrofuranLösungsmittel

Versuchsvorschrift

A mixture of 5-bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid 3-tert-butoxycarbonyl-propyl ester (8.2 g, 15.3 mmol) and LiOH (19.1 mL, 4 N, 76.6 mmol) in THF (150 mL) was stirred at rt for 16 hrs. The mixture was acidified by saturated NaHSO4 (50 mL) and extracted with ethyl acetate. The ethyl acetate layer was dried over Na2SO4, filtered and concentrated. The residue was purified via silica gel flash chromatography (eluting with 50% ethyl acetate in hexane), followed by crystallization in hexane/ethyl acetate (10/1) to afford 5-bromo-2-(3-tert-butoxycarbonyl-propoxy)-4-chloro-benzoic acid as white crystals (2.5 g). MS [M−(iso-butene+OH)]+: 320.8; tR=2.38 min. (method 1)

Aufarbeitung

  1. extractionextracted with ethyl acetate
  2. dry with materialThe ethyl acetate layer was dried over Na2SO4
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customThe residue was purified via silica gel flash chromatography (eluting with 50% ethyl acetate in hexane)
  6. customfollowed by crystallization in hexane/ethyl acetate (10/1)

Quellen und Nachweise

ORD-Eintrag
ord-00f41868b7da46239da67db3dccc7990
Quelldatensatz
uspto-grants-2011_12
Patentnummer
US08084614B2

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