反应详情

90% m-chloroperbenzoic acid (2.5 g) is added in the course of about 15 minutes, at a temperature close to 20° C., to 2-imino-3-(3-methylthiopropyl)-6-trifluoromethoxybenzothiazoline (4.2 g) in solution in a mixture (100 cc) of water and dioxane (40/60 by volume). The reaction mixture is stirred at the same temperature for 72 hours. After adding to distilled water (500 cc) and neutralising with 1N sodium hydroxide solution, the reaction mixture is extracted with dichloromethane. After drying over magnesium sulphate and concentrating to dryness under reduced pressure and then purifying by chromatography on a silica column using a mixture of ethyl acetate and methanol (80/20 by volume) as eluent, (RS)-2-imino-3-(3-methylsulphinylpropyl)-6-trifluoromethoxybenzothiazoline (1.2 g) melting at 114° C. is obtained.

1. additionAfter adding
2. distillationto distilled water (500 cc)
3. extractionneutralising with 1N sodium hydroxide solution, the reaction mixture is extracted with dichloromethane
4. dry with materialAfter drying over magnesium sulphate
5. concentrationconcentrating to dryness under reduced pressure
6. custompurifying by chromatography on a silica column
7. additiona mixture of ethyl acetate and methanol (80/20 by volume) as eluent