• YAKHAK HOEJI
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• v.44 no.6
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• pp.494-498
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• 2000

Noble 7,7'-substituted (or unsubstituted) 4-oxo-1,1',2,2'-dibenzothiazine-3,3'-dicarboxylic acid methyl ester 1,1,1',1'-tetraoxide 3,4'-yl ethers 2a-h were synthesized through the dehydration of 7-substituted (or unsubstituted) 4-hydroxy-1,2-benzothiazine-3-carboxylic acid methyl ester 1,1-dioxides 1a-h using silver(I) oxide for the development of new nonsteroidal antiinflammatory drugs (NSAIDs). Optimal reaction was proceeded through stirring of distilled acetone using 100 mol% of silver(I) oxide at room temperature for 24-68 hrs.