Réaction #2460299

Équation de réaction

2-(3-methoxyphenylthio)benzoic acid

acetic anhydride

methanesulfonic acid

→

3-methoxythioxanthen-9-one

Conditions de réaction

Traitement

1. 1
   TempératureThe mixture was heated
2. 2
   Températureat reflux for 2 h
3. 3
   Températurecooled
4. 4
   ExtractionThe crude product was extracted with dichloromethane
5. 5
   Lavagethe extract was washed with 10% aqueous NaHCO3
6. 6
   SéchageThe solution was dried (MgSO4)
7. 7
   Concentrationconcentrated
8. 8
   AutreThe product was purified by successive recrystallizations from toluene/heptane and from isopropanol
9. 9
   Autreto provide 1.57 g (37% of theory) of a yellow powder

Mode opératoire

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).

Source