反应详情

5-hydroxy-1,3-benzoxathiol-2-one (14.0 grams), was mixed with ethyl isocyanatoacetate (11.9 grams) and 0.84 gram of triethylamine in 165 milliliters of methyl ethyl ketone. The resulting mixture was then heated at reflux temperature for one hour and ten minutes and was allowed to cool and stand at ambient temperature for 15 hours. The solvent was then removed by evaporation in vacuo. The white, solid residue was recrystallized from a solution of 2% ethyl acetate in carbon tetrachloride. The resulting white crystalline solid had a melting point of 94.5°-96.5° C. This product was then recrystallized from a mixture of ethyl acetate and methylcyclohexane to give the desired purified product, 5-[(carbethoxymethyl)-carbamoyloxy]-1,3-benzoxathiol-2-one as colorless crystals having a melting point of 97.5°-98.5° C. Elemental analysis calculated for C12H11NO6S (percent): carbon--48.48; hydrogen--3.73; nitrogen--4.71. Found: carbon--48.6; hydrogen--3.84; nitrogen--4.80.

1. temperatureThe resulting mixture was then heated
2. temperatureat reflux temperature for one hour
3. customten minutes
4. temperatureto cool
5. customThe solvent was then removed by evaporation in vacuo
6. customThe white, solid residue was recrystallized from a solution of 2% ethyl acetate in carbon tetrachloride
7. customThis product was then recrystallized from a mixture of ethyl acetate and methylcyclohexane
8. customto give the
9. customdesired purified product, 5-[(carbethoxymethyl)-carbamoyloxy]-1,3-benzoxathiol-2-one as colorless crystals