1-乙氧基-2-异氰酸酯

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:0.00; pressure:0.00; stir:

反应条件: temp:25.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: 1 ml of triethylamine was added to a solution of 14.6 g of 3-hydroxy-5-ethoxy-1,2,4-thiadiazole in 140 ml of tetrahydrofuran and then 23 g of ethoxyethyl isocyanate were added dropwise. The mixture was stirred for 2 hours at 25° C and was concentrated to dryness. The residue was chromatographed over silica gel and elution with a 4-6 benzene-ethyl acetate mixture yielded 14 g of 2-(N-β-ethoxyethylcarbamoyl)-5-ethoxy-1,2,4-thiadiazole-3-one melting at <50° C. was concentrated to dryness The residue was chromatographed over silica gel and elution with a 4-6 benzene-ethyl acetate mixture

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: To the above solution of 2-ethoxyethyl isocyanate was added a solution of 5-fluorouracil (2.60 g.) in N,N-dimethylacetamide (20 ml.) at 80° and stirred for further 3 hours at the same temperature. The resultant mixture was diluted with ethyl acetate (200 ml.), washed with saturated sodium chloride aqueous solution (each 30 ml., 2 times), dried over magnesium sulfate, treated with activated charcoal, filtered and evaporated in vacuo. The residue was recrystallized from ethyl acetate to give 1-[N-(2-ethoxyethyl)carbamoyl]-5-fluorouracil (1.82 g.). washed with saturated sodium chloride aqueous solution (each 30 ml , 2 times), dried over magnesium sulfate treated with activated charcoal filtered evaporated in vacuo The residue was recrystallized from ethyl acetate