Methanesulfonic Acid → HCID 4086611, Verbindung
Reaktionsgleichung
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([S:9][C:10]2[CH:18]=[CH:17][CH:16]=[CH:15][C:11]=2[C:12]([OH:14])=O)[CH:6]=[CH:7][CH:8]=1.C(OC(=O)C)(=O)C.CS(O)(=O)=O>>[CH3:1][O:2][C:3]1[CH:8]=[CH:7][C:6]2[C:12](=[O:14])[C:11]3[C:10]([S:9][C:5]=2[CH:4]=1)=[CH:18][CH:17]=[CH:16][CH:15]=3Komponenten
4
Versuchsvorschrift
Finally, 3-methoxythioxanthen-9-one (S-18) was prepared. To a mixture of 2-(3-methoxyphenylthio)benzoic acid (4.60 g, 18 mmol) and 27 g (265 mmol) of acetic anhydride was added dropwise 1.70 g (18 mmol) of methanesulfonic acid. The mixture was heated at reflux for 2 h, cooled to ambient, and poured very slowly onto 250 g of ice. The crude product was extracted with dichloromethane, and the extract was washed with 10% aqueous NaHCO3 and then with brine. The solution was dried (MgSO4), passed through a short column of silica gel, and concentrated to deposit an orange solid. The product was purified by successive recrystallizations from toluene/heptane and from isopropanol to provide 1.57 g (37% of theory) of a yellow powder. 1H NMR (CDCl3): δ 3.91 (s, 3H), 6.95 (d, 1H), 7.01 (dd, 1H), 7.4-7.6 (m, 3H), 8.55 (d, 1H), 8.59 (d, 1H).