Reaktion #164549

Reaktionsgleichung

5-bromo-1-[2-oxo-2-(4-trifluoromethyl-phenyl)-ethyl]-1H-pyrrole-2-carboxylic acid methyl ester

ammonium acetate

water

→

6-bromo-3-(4-trifluoromethyl-phenyl)-2H-pyrrolo[1,2-a]pyrazin-1-one

Ausbeute 97.4%

Lösungsmittel

acetic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThe resulting precipitate was collected by filtration
2. 2
   Waschenwashed with water
3. 3
   Sonstigedried in vacuo

Vorschrift

A mixture of 5-bromo-1-[2-oxo-2-(4-trifluoromethyl-phenyl)-ethyl]-1H-pyrrole-2-carboxylic acid methyl ester (0.09 g, 0.23 mmol) and ammonium acetate (90 mg, 1.17 mmol) in glacial acetic acid (3 mL) were heated to 130° C. overnight. At this time, the reaction was treated with water. The resulting precipitate was collected by filtration, washed with water and dried in vacuo to afford 6-bromo-3-(4-trifluoromethyl-phenyl)-2H-pyrrolo[1,2-a]pyrazin-1-one (80 mg, 97%) as light brown solid. 1H NMR (chloroform-d) δ ppm 7.75-7.83 (m, 7H), 7.68-7.74 (m, 2H), 7.27 (d, J=1.5 Hz, 1H), 7.23 (s, 1H), 7.20 (s, 1H). LC-MS calcd. for C14H7BrF3N2O [(M−H)−] 356, obsd. 354.9.

Quelle