[F:1][C:2]([F:15])([F:14])[S:3]([O:6]S(C(F)(F)F)(=O)=O)(=[O:5])=[O:4].O[C:17]1[C:18](=[O:26])[N:19]([CH3:25])[CH:20]=[C:21]([O:23][CH3:24])[N:22]=1.N1C=CC=CC=1>C(Cl)Cl>[CH3:24][O:23][C:21]1[N:22]=[C:17]([O:6][S:3]([C:2]([F:15])([F:14])[F:1])(=[O:5])=[O:4])[C:18](=[O:26])[N:19]([CH3:25])[CH:20]=162 g of trifluoromethanesulfonic acid anhydride are added dropwise to a suspension of 31.2 g of 3-hydroxy-5-methoxy-1-methylpyrazin-2-one, 15.8 g of pyridine and 500 ml of methylene chloride at 20°-25° C. The solution formed is stirred at 20°-25° C. for a further 2 hours, and 200 ml of ice-water are then added. The organic phase is separated off, washed with 10% sodium bicarbonate solution and water, dried over sodium sulfate and evaporated to give 39.5 g of 5-methoxy-1-methyl-3-trifluoromethylsulfonyloxy-pyrazin-2-one of melting point 107°-108° C.
Wird geladen…
