Reaktion #364533

Reaktionsgleichung

dimethylcarbamoylchloride

Ethyl 3-amino-4,4,4-trifluorocrotonate

sodium hydride

→

title product

Ausbeute 71.2%

Ethyl 3-[(N,N-dimethylcarbamoyl)amino]-4,4,4-trifluorocrotonate

Ausbeute 71.2%

Lösungsmittel

water

N,N-dimethyl-formamide

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto warm to and
2. 2
   workup.WAITheld at room temperature for 2 hours
3. 3
   Extraktionextracted with ethyl acetate (2×150 mL)
4. 4
   SonstigeThe combined organic layers are dried
5. 5
   Filtrationfiltered
6. 6
   Einengenconcentrated
7. 7
   Sonstigethe mineral oil layer is removed
8. 8
   Sonstigeto obtain a residue

Vorschrift

Ethyl 3-amino-4,4,4-trifluorocrotonate (18.4 g, 100 mmol) is added to a stirred solution of sodium hydride (60% in mineral oil, 9.6 g, 250 mmol) in N,N-dimethyl-formamide (60 mL) at 5° C. under nitrogen over a 60 minute period. The reaction mixture is allowed to warm to and held at room temperature for 15 minutes, cooled to 5° C., and treated with dimethylcarbamoylchloride (21.6 g, 200 mmol) over a 60 minute period. The resultant solution is then warmed to and held at room temperature for 2 hours, diluted with water (150 mL), and extracted with ethyl acetate (2×150 mL). The combined organic layers are dried, filtered and concentrated, and the mineral oil layer is removed to obtain a residue. Flash column chromatography of the residue on silica gel using a 85:15 hexanes/ethyl acetate solution gives the title product as a yellow liquid (18.1 g, 71% yield): 1H NMR (DMSO-d6) δ9.18 (s,1H), 5.85 (s, 1H), 4.20 (q, 2H), 2.89 (s, 6H), 1.18 (t, 3H); 19F NMR δ−65.7 (s).

Quelle