Reaktion #635136

Reaktionsgleichung

tert-butyl trichloroacetimidate

sodium bicarbonate

tert-Butyl trichloroacetimidate

2-methyl-3-nitrophenol

boron trifluoride etherate

→

2-methyl-3-tert-butoxynitrobenzene

Lösungsmittel

THF

cyclohexane

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperatura solution was maintained)
2. 2
   Sonstige(reaction remains in solution)
3. 3
   workup.STIRRINGafter stirring at room temperature for 5 h
4. 4
   Filtrationthe mixture was filtered
5. 5
   Waschenrinsed with dichloromethane
6. 6
   Sonstigeevaporated to dryness
7. 7
   Sonstigeto provide a white solid
8. 8
   SonstigeThe solid was triturated with dichloromethane
9. 9
   Filtrationthe white solid filtered
10. 10
    EinengenThe filtrate was concentrated
11. 11
    Sonstigeloaded onto a flash column for purification (hexane:EtOAc 9:1)

Vorschrift

To a solution of 2-methyl-3-nitrophenol K1 (1.1 g; 7.18 mmol) in THF (13 mL) was added cyclohexane (27 mL; a solution was maintained). tert-Butyl trichloroacetimidate K2 (5.36 mL; 28.73 mmol) was added followed by a catalytic amount of boron trifluoride etherate (143.8 μL; 1.14 mmol) and the reaction was stirred at room temperature for 15 h. The reaction was incomplete (by analytical HPLC) and an additional amount of tert-butyl trichloroacetimidate (1.4 mL; 7.51 mmol) was added (reaction remains in solution). The reaction was complete after stirring at room temperature for 5 h. Solid sodium bicarbonate was added, and the mixture was filtered, rinsed with dichloromethane and evaporated to dryness to provide a white solid. The solid was triturated with dichloromethane, the white solid filtered and discarded (=trichloroacetimide). The filtrate was concentrated and loaded onto a flash column for purification (hexane:EtOAc 9:1) to provide the pure 2-methyl-3-tert-butoxynitrobenzene K3 (1.17 g; 78%). Homogeneity by HPLC (TFA) @ 220 nm: 96%

Quelle