Sulfur → 2H-1,4-Thiazin-3(4H)-one, 5-methyl-6-(4-pyridinyl)-

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Reaction Conditions

Reaction Steps

5-methyl-6-[1-(2,2,2-trichloroethoxycarbonyl)-1,4-dihydro-4-pyridinyl]-2H-1,4-thiazin-3(4H)-one (2.14 g) was mixed well with sulfur sublimed (10.7 g) in a mortar and the mixture was stirred at 140° C. for 1.5 hours. Then, the mixture was cooled to ambient temperature. The obtained solid was ground and was extracted with methanol using Soxhlet extractor. Methanol was removed under reduced pressure. The residue was dissolved in 50 ml of 2N hydrochloric acid. The insoluble matter was removed by filtration and the filtrate was adjusted to pH 7.2 by 2N aqueous sodium hydroxide. The resulting precipitates were collected by filtration and the filtrate was extracted with chloroform (20 ml×5 times) and was evaporated to dryness. After combined with the above solid, the residue was recrystallized from isopropanol to give the titled compound (0.88 g, yield 76.5%) as pale yellow plates.

Provenance & Evidence