反应详情

Zinc powder (1 g) was added to a stirred solution of 5-methyl-6-[1-(2,2,2-trichloroethoxycarbonyl)-1,4-dihydro-4-pyridinyl]-2H-1,4-thiazin-3(4H)-one (1 g) in formic acid (14 ml), and the reaction mixture was stirred at room temperature for 3 hours. The insoluble solid was removed by filtration. The filtrate was evaporated to dryness and the residue was dissolved in water (30 ml). The solution was adjusted to pH 7.0 by addition of 1N sodium hydroxide aqueous solution. The precipitates were extracted with chloroform (although the solution was converted into an emulsion at this extracting step, the operation was facilitated by using a filter aid such as "Avicel"). The extract was dried over anhydrous magnesium sulfate and was evaporated under reduced pressure. The crude product was purified by the preparative thin layer chromatography [Merck TLC plate, silica gel 60F254 t (particles average porous diameter 60A, Fluorescent substance Zn2SiO4 /Mn), 20×20 cm, t=1 mm, chloroform/methanol= 20/1] to give 200 mg of 5-methyl-6-(4-pyridinyl)-2H-1,4-thiazin-3(4H)-one. The physical properties were as described above.

1. customThe insoluble solid was removed by filtration
2. customThe filtrate was evaporated to dryness
3. dissolutionthe residue was dissolved in water (30 ml)
4. additionThe solution was adjusted to pH 7.0 by addition of 1N sodium hydroxide aqueous solution
5. extractionThe precipitates were extracted with chloroform (although the solution
6. dry with materialThe extract was dried over anhydrous magnesium sulfate
7. customwas evaporated under reduced pressure
8. customThe crude product was purified by the preparative thin layer chromatography [Merck TLC plate, silica gel 60F254 t (particles average porous diameter 60A, Fluorescent substance Zn2SiO4 /Mn), 20×20 cm, t=1 mm, chloroform/methanol= 20/1]