• Archives of Pharmacal Research
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• v.12 no.1
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• pp.17-21
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• 1989

We have reported earlier on the reactivity of 7-dithiocarboxy-3-phenyl-5,6-dihydro imidazo[2,1-b]thiazolium-betaine with several para-substituted phenacyl bromides. In this work reactions of 7-dithiocarboxy-3-phenyl(or methyl)-5,6-dihydro imidazo[2,1-b]thiazolium-betaine with a series of aliphatic alkylating agents of ${\alpha}$ -halo ketone,${\gamma}$-halo koto ester and ${\alpha}$ -halo ester were examined for the similar purpose. In case of ${\alpha}$-halo ketone or ${\gamma}$-halo koto ester such as ${\alpha}$ -chloro acetone or ethyl 4-chloro acetoacetate new biheterocyclic compound was obtained via ring transformation reaction. However, reaction of the betaine with methyl(or ethyl) bromoacetate used as a ${\alpha}$-halo ester, gave, in-stead, S-alkylated quarternary ammonium salt.

• Bulletin of the Korean Chemical Society
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• v.9 no.3
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• pp.164-166
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• 1988

7-Dithiocarboxy-3-phenyl-5,6-dihydro imidazo[2,1-b]thiazolium-betaine (2) was prepared by treatment of 3-phenyl-5,6-dihydro imidazo[2,1-b]thiazole (1) with carbon disulfide in acetone at room temperature. On the reaction of 2 with para-substituted phenacyl bromides (4) having the electron withdrawing property by virtue of (+) resonance (R) < (-) inductive (I) or (-) resonance (R), (-) inductive (I) effect, ring transformation product p-substituted-2-[2-[7-(p-substituted benzoyl)-5-thioxo-2,3-dihydro-1H-imidazo[1,2-c] thiazol-1-yl]-2-phenylvinylthio] acetophenone (6) was obtained; however, when R is electron donating grops with (+) resonance (R) > (-) inductive (I) effect the quarternary ammonium salt 7-(p-substituted phenyl) carbonyl methyl-3-phenyl-5,6-dihydro imidazo [2,1-b] thiazolium bromide (8) is formed. The reaction of 2 with unsubstituted-phenacyl bromide (R = H), on the other hand, gives 6a and 8a to the similar ratio, respectively.