Reaktion #566564

Reaktionsgleichung

di-tert-butyl 2,2-bis[(4-pyridyl)methyl]malonate

hydrogen chloride

ethyl acetate

→

methyl 2,2-bis[(4-pyridyl)methyl]acetate

Ausbeute 51.0%

Lösungsmittel

trifluoroacetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   EinengenThe reaction mixture was concentrated under reduced pressure
2. 2
   Temperaturthe resultant concentrated residue was heated for 20 minutes in a bath
3. 3
   Sonstigecontrolled at 200° C.
4. 4
   workup.DISSOLUTIONdissolved in methanol (170 ml)
5. 5
   workup.STIRRINGthe mixture was stirred for 2 hours
6. 6
   Einengenconcentrated under reduced pressure
7. 7
   workup.ADDITIONThe resultant concentrated residue was made basic by addition of aqueous 2.5N sodium hydroxide
8. 8
   Extraktionextracted with chloroform
9. 9
   WaschenThe organic layer was washed with saturated brine
10. 10
    Trocknendried over anhydrous sodium sulfate
11. 11
    Einengenconcentrated under reduced pressure
12. 12
    SonstigeThe resultant crude oil was purified by column chromatography on silica gel

Vorschrift

The crude crystals (17.1 g) of di-tert-butyl 2,2-bis[(4-pyridyl)methyl]malonate synthesized by the above process were dissolved in trifluoroacetic acid (90 ml), and the solution was stirred at room temperature for 30 minutes. The reaction mixture was concentrated under reduced pressure, and the resultant concentrated residue was heated for 20 minutes in a bath controlled at 200° C. and then dissolved in methanol (170 ml). A 4N hydrogen chloride in ethyl acetate (100 ml; 400 mmol) was added to the solution, and the mixture was stirred for 2 hours and then concentrated under reduced pressure. The resultant concentrated residue was made basic by addition of aqueous 2.5N sodium hydroxide and extracted with chloroform. The organic layer was washed with saturated brine, dried over anhydrous sodium sulfate and then concentrated under reduced pressure. The resultant crude oil was purified by column chromatography on silica gel, thereby obtaining 6.0 g (yield: 51%) of methyl 2,2-bis[(4-pyridyl)methyl]acetate as a colorless oil.

Quelle