| 摘要 |
<p>PURPOSE:To provide a new 3-thioxo-1,4-benzothiazine derivative having lipid peroxide production suppressing action as well as protein-stabilizing action and useful as pharmaceuticals such as agent for the treatment of cataract and provide its new synthetic intermediate. CONSTITUTION:A compound of formula I (R<1> is hydroxy which may be protected with a protecting group; R<2> is a lower alkyl; R<3> is H, a lower alkyl or hydroxy or a lower alkoxy which may be protected with a protecting group; R<4> is carboxyl which may be converted to an ester or an amide; A is an alkylene) or its salt, e.g. 4-carboxymethyl-2-(3, 5-di-t-butyl-4- hydroxybenzylidene)-3, 4-dihydro-3-thioxo-2H-1,4-benzothiazine. The compound of formula I can be produced e.g. by treating a new compound of formula III with a Lowessons reagent or phosphorus pentasulfide to obtain a new compound of formula II and reacting the compound with a compound of formula IV (X is a halogen, an alkylsulfonyl or an arylsulfonyl).</p> |
