Acetic Anhydride → 5-Bromo-4-methylpyridin-3-yl acetate

HRID 1502229Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1502229
B(F)(F)F.CCOCC.[Br:10][C:11]1[C:12]([CH3:18])=[C:13](N)[CH:14]=[N:15][CH:16]=1.COCCOC.N(OC(C)(C)C)=O.[C:32]([O:35]C(=O)C)(=[O:34])[CH3:33]>CCCCC>[C:32]([O:35][C:13]1[CH:14]=[N:15][CH:16]=[C:11]([Br:10])[C:12]=1[CH3:18])(=[O:34])[CH3:33]

Komponenten

7

Edukt 5

HCID 7918Acetic AnhydrideHCID 8000Boron trifluoride etherateHCID 80711,2-DimethoxyethaneHCID 10906Tert-Butyl nitriteHCID 70606795-Bromo-4-methylpyridin-3-amine

Produkt 1

HCID 679749105-Bromo-4-methylpyridin-3-yl acetateAusbeute 38,4 %

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 8003PentaneLösungsmittel

Reaktionsbedingungen

Temperatur
-15 °C

Versuchsvorschrift

To a flask containing boron trifluoride etherate (0.35 mL, 2.8 mmol) at −15° C. was added a solution of 5-bromo-4-methylpyridin-3-amine (249.0 mg, 1.331 mmol) in 1,2-dimethoxyethane (2.0 mL, 19 mmol). Tert-butyl nitrite (0.20 mL, 1.7 mmol) was then added dropwise and the reaction mixture stirred at −15° C. for one hour. 3 mL pentane was then added and the solid material collected by vacuum filtration. The solid material was dissolved in acetic anhydride (2.0 mL, 21 mmol) and stirred at 100° C. for one hour. The solvent was evaporated in vacuo, and the residue then suspended in 2M aqueous Na2CO3 and extracted twice with dichloromethane. The combined organic extracts were dried over MgSO4, filtered, and evaporated in vacuo. The crude product was purified via flash chromatography on silica gel (24 g silica, solvent gradient: 0-40% ethyl acetate in heptanes) to yield 117.7 mg (38%) of 5-bromo-4-methylpyridin-3-yl acetate. LCMS (ESI): M+H=230.2; 1H NMR (400 MHz, DMSO-d6) δ 8.61 (s, 1H), 8.35 (s, 1H), 2.37 (s, 3H), 2.23 (s, 3H).

Aufarbeitung

  1. filtrationthe solid material collected by vacuum filtration
  2. stirringstirred at 100° C. for one hour
  3. customThe solvent was evaporated in vacuo
  4. extractionextracted twice with dichloromethane
  5. dry with materialThe combined organic extracts were dried over MgSO4
  6. filtrationfiltered
  7. customevaporated in vacuo
  8. customThe crude product was purified via flash chromatography on silica gel (24 g silica, solvent gradient: 0-40% ethyl acetate in heptanes)

Quellen und Nachweise

ORD-Eintrag
ord-3562512a90ec4c1db647c8921b21b3a6
Quelldatensatz
uspto-grants-2015_12
Patentnummer
US09206175B2

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