Synthesis of 5,6-Dihydro-6- methyl-4H- thieno [2,3-b] thiopyrane-4-one-2-sulfonamide

3-(2-Mercaptothiophene)butanoic acid (2) was produced from crotonic acid and 2-mercaptothiophene,through condensation. 5,6-dihydro-6- methyl-4H- thieno[2,3-b] thiopyrane-4-one(3)was produced through chlorination by thionyl chloride and cyclization by anhydrous of aluminium chloride,and then 5,6-dihydro-6- methyl-4H- thieno[2,3-b]thiopyrane-4-one-2-sulfonamide(1)was produced through sulfonatio,chlorination and ammonolysis. The optimum technological condition gained through homogeneous design were as follow:n(2) ∶ n(SOCl2) ∶ n(AlCl3)=1 ∶ 3 ∶ 1.5,and reaction temperature was 20℃ for 2 hours. The total yield was 30.49% based on 2-mercaptothiophene. The products were characterized by IR ,MS and 1H NMR.