| 摘要 |
1510540 6 - Methyl - 3,4 - dihydro - 1,2,3- oxathiazine - 4 - one - 2,2 - dioxide HOESCHT AG 17 July 1975 [18 July 1974] 30021/75 Addition to 1340911 Heading C2C 6 - Methyl - 3,4 - dihydro - 1,2,3 - oxathiazin- 4 - one - 2,2 - dioxide or non - toxic salt thereof is made by reacting acetoacetic acid with fluorosulphonyl isocyanate, at -20‹ to +50‹C., in the presence of as complex forming agent, 0À5-2 moles per mole of isocyanate of an alkali metal fluoride pyridine; guinoline or a tert. amine NR 1 R 2 R 3 , where R 1 -R 3 are C 1-10 are C 1-10 alkyl or two of them are C 4-5 alkylene, which may contain a N, O or S atom, or one of them is phenyl, or a mixture thereof, and transforming the resulting acetoacetamide-N- sulphofluoride to a salt of the desired oxathiazinone by reaction with an aqueous or alcoholicbase and, if desired, acidifying the salt thereto base and, if desired, acidifying the salt to liberate the free oxathiazinone. |
