Reaktion #425314

Reaktionsgleichung

Benzyl (4aR,7aR)-2-(benzoylamino)-7a-(5-bromothiophen-2-yl)-4a,5,7,7a-tetrahydropyrrolo[3,4-d][1,3]thiazine-6(4H)-carboxylate

1-butylimidazole

toluene

→

title compound

Ausbeute 74.0%

Benzyl (4aR,7aR)-2-(benzoylamino)-7a-(5-cyanothiophen-2-yl)-4a,5,7,7a-tetrahydropyrrolo[3,4-d][1,3]thiazine-6(4H)-carboxylate

Ausbeute 74.0%

Lösungsmittel

ethyl acetate

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigefitted with a stirrer bar
2. 2
   workup.WAITA stream of nitrogen is passed over the mixture for a few minutes
3. 3
   Sonstigethe pressure tube is then sealed
4. 4
   TemperaturThe resulting dark mixture is cooled to room temperature
5. 5
   Filtrationfiltered through a pad of diatomaceous earth
6. 6
   Waschenwhile rinsing with ethyl acetate (100 mL) and water (15 mL)
7. 7
   SonstigeThe layers of the filtrate are separated
8. 8
   Waschenthe organic layer is further washed with water (2×30 mL) and brine (30 mL)
9. 9
   TrocknenThe organic phase is dried over sodium sulfate
10. 10
    Filtrationfiltered
11. 11
    Einengenconcentrated under reduced pressure
12. 12
    SonstigeThe residue is purified by silica gel flash chromatography
13. 13
    Wascheneluting with a hexanes/ethyl acetate, gradient from 80:20 to 0:100

Vorschrift

Benzyl (4aR,7aR)-2-(benzoylamino)-7a-(5-bromothiophen-2-yl)-4a,5,7,7a-tetrahydropyrrolo[3,4-d][1,3]thiazine-6(4H)-carboxylate (3.88 g, 6.97 mmol), anhydrous potassium hexacyanoferrate (II) (2.57 g, 6.97 mmol) (prepared as cited in Schareina, T.; et al Synthesis, 2008, 20, 3351-3355), copper (I) iodide (398 mg, 2.09 mmol), 1-butylimidazole (2.8 mL, 20.9 mmol), and toluene (23 mL) are added to a 60 mL glass pressure tube fitted with a stirrer bar. A stream of nitrogen is passed over the mixture for a few minutes and the pressure tube is then sealed. The stirred mixture is heated at 145° C. for 18 hours. The resulting dark mixture is cooled to room temperature. The mixture is diluted with ethyl acetate (100 mL) and water (15 mL) and vacuum filtered through a pad of diatomaceous earth while rinsing with ethyl acetate (100 mL) and water (15 mL). The layers of the filtrate are separated and the organic layer is further washed with water (2×30 mL) and brine (30 mL). The organic phase is dried over sodium sulfate, filtered, and concentrated under reduced pressure. The residue is purified by silica gel flash chromatography eluting with a hexanes/ethyl acetate, gradient from 80:20 to 0:100, to give the title compound (2.59 g, 74%) as a white foam: ES/MS (m/z): 503.2 (M+H).

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