反应详情

Ethyl chloroformate (1.0 g) was added dropwise to a stirred solution of thiazole (0.79 g) in dichloromethane (10 ml) under ice-cooling and the mixture was stirred at room temperature for 0.5 hour. Then, 2,2-dimethoxy-5-methyl-2H-1,4-thiazin-3(4H)-one (1.47 g) was added, and the mixture was stirred at room temperature for 3 hours. The solution was washed with saturated sodium bicarbonate aqueous solution, dried over magnesium sulfate and evaporated to dryness. The residue was chromatographed on silica gel (Merck Lobar column size B: Art.10401, solvent: ethyl acetate-n-hexane=2:3) to give 2,2-dimethoxy-5-methyl-6-(3-ethoxycarbonyl-2,3-dihydro-2-thiazolyl)-2H-1,4-thiazin-(4H-one (510 mg, yield 19%) as colorless prisms.

1. temperaturecooling
2. stirringthe mixture was stirred at room temperature for 3 hours
3. washThe solution was washed with saturated sodium bicarbonate aqueous solution
4. dry with materialdried over magnesium sulfate
5. customevaporated to dryness
6. customThe residue was chromatographed on silica gel (Merck Lobar column size B: Art.10401, solvent: ethyl acetate-n-hexane=2:3)