Sulfur → 103807-33-6

Participants

Reaction Conditions

Reaction Steps

Sulfur sublimed (0.7 g) was added to a solution of 2,5-dimethyl-6-[1-(2,2,2-trichloroethoxycarbonyl)-1,4-dihydro-4-pyridinyl]-2H-1,4-thiazin-3(4H)-one (1.5 g) in dimethylformamide (20 ml) and the mixture was stirred at 140° C. for 2 hours. Then, the mixture was allowed to cool to ambient temperature and the solvent was removed under reduced pressure. The residue was dissolved in 2N hydrochloric acid and the insoluble matter was removed by filtration. The filtrate was adjusted to pH 7-8 by 2N aqueous sodium hydroxide. The precipitated crude crystals were chromatographed on silica gel (Wakogel C-200) column, using chloroform-methanol (=20:1) as an eluant to give pale yellow crystals. These crude crystals were dissolved in chloroform, were washed with water and were dried over magnesium sulfate. The solvent was removed under reduced pressure to give the titled compound (0.43 g, yield 52%) as white crystals.

Provenance & Evidence