Chlorosulfonic acid → 4-Methoxy-3-[4-(2,2,2-trifluoro-acetyl)-piperazin-1-yl]-benzenesulfonyl chloride
Reaktionsgleichung
[F:1][C:2]([F:20])([F:19])[C:3]([N:5]1[CH2:10][CH2:9][N:8]([C:11]2[CH:16]=[CH:15][CH:14]=[CH:13][C:12]=2[O:17][CH3:18])[CH2:7][CH2:6]1)=[O:4].[Cl:21][S:22](O)(=[O:24])=[O:23]>ClCCl>[CH3:18][O:17][C:12]1[CH:13]=[CH:14][C:15]([S:22]([Cl:21])(=[O:24])=[O:23])=[CH:16][C:11]=1[N:8]1[CH2:7][CH2:6][N:5]([C:3](=[O:4])[C:2]([F:1])([F:19])[F:20])[CH2:10][CH2:9]1Komponenten
4
Edukt 2
Produkt 1
Reagenzien, Katalysatoren, Lösungsmittel 1
Versuchsvorschrift
A solution of 2,2,2-trifluoro-1-[4-(2-methoxy-phenyl)-piperazin-1-yl]-ethanone (14 g; 0.48 mol) in dichloromethane (20 mL) was added to chlorosulfonic acid (75 mL) in such a rate that the inner temperature did not exceed −5° C. After 10 min at this temperature, the solution was poured slowly onto ice-water (500 g), the precipitate was filtered and washed with cold water (2×200 mL) and cold diethyl ether (200 mL). The resulting solid was recrystallized from diethyl ether to give 4-methoxy-3-[4-(2,2,2-trifluoro-acetyl)-piperazin-1-yl]-benzenesulfonyl chloride as white powder (7.7 g; 41%), MS, MH+ 387, m. p. 125-127.3° C.