KIM, DC KIM, DJ PARK, SW YOO, KH 2024-01-21T20:36:14Z 2024-01-21T20:36:14Z 2022-01-10 1995-09 0022-152X https://pubs.kist.re.kr/handle/201004/145008 The 1,4-dipolar cycloaddition of 3-phenyl-7-[N-phenyl(carbamoyl)]-5,6-dihydroimidazo[2,1-b]thiazolium betaine (7d) with a series of aliphatic alkylating agents such as ethyl bromoacetate, alpha-chloroacetone, and ethyl 4-chloroacetoacetate gave a variety of new ring-expanded cycloadducts 10a-c instead of ring transformation compounds 9. This result was derived from the difference of reactivity between N- and S-alkylations of thiazolium betaines 7a,d. The advantage of our method is to prepare the triheterocyclic compounds 10a-c of complicated structure using reactive thiazolium betaine 7d in a one-pot without isolation of intermediates. Treatment of N-bridged thiazolo compounds 1a-c with benzoyl isothiocyanate led to new thiazolium betaines 2a-c, which were reacted with methyl iodide to afford the S-alkylated quarternary ammonium salts 3a-c. Synthesis of new 2-iminothiazolinium betaines 5a,b also was carried out. English HETERO CORPORATION IMIDAZOLE SYNTHESIS OF NEW THIAZOLIUM BETAINES AND THE RING EXPANSION REACTION VIA 1,4-DIPOLAR CYCLOADDITION Article 10.1002/jhet.5570320528 1 JOURNAL OF HETEROCYCLIC CHEMISTRY, v.32, no.5, pp.1581 - 1586 JOURNAL OF HETEROCYCLIC CHEMISTRY 32 5 1581 1586 scie scopus A1995TE60600028 2-s2.0-84993907221 Chemistry, Organic Chemistry Article IMIDAZOLE new thiazolium betaines