| 摘要 |
PURPOSE:To obtain a new 3-oxo-1,4-benzothiazine derivative having protein stabilizing action and lipid peroxide formation suppressing action and useful as an excellent agent for the treatment of cataract. CONSTITUTION:This 3-oxo-1,4-benzothiazine derivative is expressed by formula I [R<1> is a (protected) OH; R<2> is a lower alkyl; R<3> is H, a lower alkyl, a (protected) OH or a lower alkoxy; R<4> is a tetrazolyl, a phosphonyl(lower alkyl ester) or a sulfonyl(lower alkyl ester); A is an alkylene], e.g. 2-(3,5-di-t-butyl-4- hydroxybenzylidene)-3,4-dihydro-3-oxo-4-phosphonomethyl-2H-1,4-benzoth iazine. The compound of formula I can be produced by reacting a compound of formula II with a compound of formula X-A-CN (X is a halogen, an alkylsulfonyl, etc.) in the presence of a base and reacting the obtained compound of formula III with sodium azide. |
