反应详情

5 g. of 3-carbomethoxy-4-hydroxy-2-methyl-2H-[1]benzothieno[2,3-e]-1,2-thiazine 1,1-dioxide and 3 g. of 2-aminopyridine are treated with 150 ml. of a xylene isomer mixture and heated so that the resulting methanol distils off azeotropically. After 6 hours, the mixture is left to cool to room temperature. The cyrstals obtained are filtered off under suction and washed with a xylene mixture. After recrystallization from dimethylformamide and addition of methanol, there is obtained 4-hydroxy-2-methyl-N-(2-pyridyl)-2H-[1]benzothieno[2,3-e]-1,2-thiazine-3-carboxamide 1,1-dioxide in the form of yellow crystals of melting point 222°-224° C.

1. customdistils off azeotropically
2. waitthe mixture is left
3. customThe cyrstals obtained
4. filtrationare filtered off under suction
5. washwashed with a xylene mixture
6. customAfter recrystallization
7. additionfrom dimethylformamide and addition of methanol