反应详情

温度

140 °C

The mixture of 5-methyl-6-[1-(2,2,2-trichloroethoxycarbonyl)-1,4-dihydro-4-pyridinyl]-2H-1,4-thiazin3(4H)-one (2.14 g) and sulfur (10.7 g) was heated under stirring at 140° C. for 1.5 hours and then cooled to room temperature. The solid was extracted with methanol by using Soxhlet extractor. Methanol was removed under reduced pressure and the residue was dissolved in 50 ml of 2N hydrochloric acid. The insoluble solid was removed by filtration ad the filtrate was adjusted to pH 7.2 by 2N aqueous sodium hydroxide. The precipitates were collected by filtration and the filtrate was extracted with chloroform (20 ml×5 times) and evaporated to dryness. After combined with the above solid, the residue was recrystallized from isopropyl alcohol to give 5-methyl-6-(4-pyridinyl)-2H-1,4-thiazin-3(4H)-one (0.88 g, yield 76.5%) as light yellow plates.

1. temperaturewas heated
2. temperaturecooled to room temperature
3. extractionThe solid was extracted with methanol
4. customMethanol was removed under reduced pressure
5. dissolutionthe residue was dissolved in 50 ml of 2N hydrochloric acid
6. customThe insoluble solid was removed by filtration ad the filtrate
7. filtrationThe precipitates were collected by filtration
8. extractionthe filtrate was extracted with chloroform (20 ml×5 times)
9. customevaporated to dryness
10. customthe residue was recrystallized from isopropyl alcohol