Reaktion #1109181

Reaktionsgleichung

230a

(S)-tert-Butyl 4-(5-Bromopyrazin-2-yl)-3-methylpiperazine-1-carboxylate

diphenylmethanimine

(R)-(+)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl

Cs2CO3

→

230b

Ausbeute 98.8%

(S)-tert-Butyl 4-(5-(Diphenylmethyleneamino)pyrazin-2-yl)-3-methylpiperazine-1-carboxylate

Ausbeute 98.8%

Lösungsmittel

1,4-dioxane

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeA 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser
2. 2
   SonstigeAfter three cycles of vacuum/argon flush
3. 3
   TemperaturIt was then cooled to room temperature
4. 4
   Filtrationfiltered
5. 5
   EinengenThe filtrate was concentrated under reduced pressure
6. 6
   Sonstigethe resulting residue was purified by silica-gel column chromatography
7. 7
   Wascheneluting with petroleum ether/ethyl acetate (10:1 to 3:1)

Vorschrift

A 100-mL single-neck round-bottomed flask equipped with a magnetic stirrer and a reflux condenser was charged with 230a (2.6 g, 7.3 mmol), diphenylmethanimine (1.3 g, 7.3 mmol), Pd2(dba)3 (669 mg, 0.73 mmol), (R)-(+)-2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (968 mg, 1.46 mmol), Cs2CO3 (4.7 g, 14.6 mmol), and 1,4-dioxane (40 mL). After three cycles of vacuum/argon flush, the mixture was heated at 96° C. for 3 hrs. It was then cooled to room temperature and filtered. The filtrate was concentrated under reduced pressure and the resulting residue was purified by silica-gel column chromatography eluting with petroleum ether/ethyl acetate (10:1 to 3:1) to afford 230b as red oil (3.3 g, 75%). MS: [M+H]+ 458.3.

Quelle