| 摘要 |
4-Hydroxy 2-methyl N-(2-pyridyl) 2H-1,2-benzothiazine 3-carboxamide 1,1-dioxide of formula (I) is made by reacting 2-methyl 2H-1,2-benzothiazin -4-(3H)-one 1,1-dioxide of formula (II) with 2-pyridyl isocyanate (III) obtd. by thermal decomposition of cpd. of formula (IV) or (V), in which R is phenyl, benzyl, ethyl n-butyl, isobutyl or tert. butyl. Reaction is by fusion in a high -boiling solvent, e.g. diethylene glycol dimethyl ether, methyl naphthalene, tetralin or decalin.
|
