Studies on the synthesis and anti-inflammatory activity of 2,6-di-tert-butylphenols with a heterocyclic group at the 4-position. V. Elimination reaction of the sulfinyl group of 2,3-dihydroimidazo(2,1-b)thiazole 1-oxide.
作者:YASUO ISOMURA、KAZUO KUBO
DOI:10.1248/cpb.32.4726
日期:——
Reaction of 6-(3, 5-di-tert-butyl-4-hydroxyphenyl)-2, 3-dihydroimidazo [2, 1-b] thiazole 1-oxide (1) with superoxide anion gave 4-(3, 5-di-tert-butyl-4-hydroxyphenyl)-1-vinylimidazole (2). Compound 2 was also obtained by treatment of 1 with potassium tert-butoxide in dimethyl sulfoxide (DMSO) in the presence of oxygen, while 4-(3, 5-di-tert-butyl-4-hydroxyphenyl)-2-thioxo-1-vinyl-4-imidazoline (3) was obtained together with 2 in the absence of oxygen. When the same reaction was carried out in N, N-dimethyl formamide, 1 gave 2 and 3 in the absence of oxygen, and 4-(3, 5-di-tert-butyl-4-hydroxyphenyl)-1-vinylimidazole-2-sulfonic acid (4) in the presence of oxygen. A possible mechanistic explanation for the formation of these products is presented. Oxygenation of 6-phenyl-2, 3-dihydroimidazo [2, 1-b] thiazole 1-oxide (6) was also examined.
6-(3,5-二叔丁基-4-羟基苯基)-2,3-二氢咪唑并[2,1-b]噻唑 1-氧化物(1)与超氧阴离子反应得到 4-(3,5-二叔丁基-4-羟基苯基)-1-乙烯基咪唑(2)。在氧气存在的情况下,在二甲基亚砜(DMSO)中用叔丁醇钾处理 1,也可以得到化合物 2,而在无氧的情况下,4-(3, 5-二叔丁基-4-羟基苯基)-2-硫酮-1-乙烯基-4-咪唑啉(3)与 2 一起得到。当在 N,N-二甲基甲酰胺中进行同样的反应时,1 在无氧条件下生成 2 和 3,在有氧条件下生成 4-(3,5-二叔丁基-4-羟基苯基)-1-乙烯基咪唑-2-磺酸(4)。本文介绍了这些产物形成的可能机理。此外,还研究了 6-苯基-2,3-二氢咪唑 [2, 1-b] 噻唑 1-氧化物(6)的氧合作用。