-Sulfonylamidines. Part IV. Intramolecular cyclization of -Sulfonylamidines of 2-oxoacids: a new synthesis of 3-aminoisothiazole ,-dioxides.
作者:Francesca Clerici、Giuseppe Marazzi、Marcello Taglietti
DOI:10.1016/s0040-4020(01)92260-4
日期:1992.4
H-atom near to the SO2 group give easily an intramolecular ring-closure rection by action of potassium t-butoxide producing the 3-amino-4,5-dihydro-4-hydroxy-isothiazole S,S-dioxides 4. Compounds 4 are transformed by thionyl chloride into the corresponding chloro-derivatives 5 which in turn are dehydrochlorinated by potassium carbonate to substituted 3-amino-isothiazole S,S-dioxides 6.
带有羰基和至少一个靠近SO 2基团的H原子的α-酮酸3的N-烷基磺酰基lam啶通过叔丁醇钾的作用容易产生分子内的闭环反应,生成3-氨基-4,5。 -二氢-4-羟基异噻唑S,S-二氧化物4。化合物4通过亚硫酰氯转化为相应的氯衍生物5,其随后通过碳酸钾脱氯化氢为取代的3-氨基-异噻唑S,S-二氧化物6。