4氯5,5二甲酰基1,3不饱和磺酸内酯的制备及环化反应.pdfVIP

Preparation and Cyclization of 4-chloro-5,5-dimethyl-3-formyl-1,2-oxathiolene - 2,2-dioxide 1 Li Tian * Lunzu Liu Department of Chemistry and Life Chemistry State Key Laboratory of Elemento-Organic Tianjin Normal University Institute of Elemento-Organic Chemistry Tianjin, P. R. China 300074 Nankai University tian_lili@ Tianjin, P. R. China 300074 lunzuliu@ Abstract Chloroformylation of 5,5-dimethyl-1,2-oxathiolan-4-one 2,2-dioxide 4 with Vilsmeier reagent (DMF/POCl3) led to the formation of cyclic β-chlorovinylaldehyde (4-chloro-5,5-dimethyl-3-formyl-1,2-oxathiolene 2,2-dioxide 5). Compound 5 reacted with formamidine, o-amino-phenol, phthalamine, amino-pyrazole and amino-tetrazole to give the corresponding heterocyclic compounds. Keywords: Vilsmeier reagent, chloroformylation, β-chlorovinylaldehyde, heterocyclic compounds. 1 Introduction The Vilsmeier reagent, HCONR R /POCl has found extensive application in the synthesis of aldehyde 1 2 3, derivatives and formamidines[1]. The reagent is an equilibrium mixture of two iminium salts, the more reactive being the β-phosphoryliminium chloride (A) rather than the β-chloroiminium phosphate (B) [2] (Figure 1). We recently reported that the Vilsmeier’s reaction applied on acetylphosphonate led s