Direct access to 1,4-benzothiazine 4,4-dioxides and 4-oxides via a domino reaction
作者:Özge Kavas、Cevher Altug
DOI:10.1016/j.tet.2017.03.056
日期:2017.5
The domino reactions of 2-fluoro benzensulfonyl acetonitrile and α-chloro oximes in the presence of Cs2CO3 in aprotic high boiling point solvents have been achieved to provide isoxazole−fused 4H-1,4-benzothiazine-4,4-dioxides via an unprecedented transition metal-free one-pot addition/cyclization process. The tunable synthesis of either isoxozolo-1,4-benzothiazin-4-oxides or their precursor 5-aminoisoxazoles
在质子惰性高沸点溶剂中,在Cs 2 CO 3存在下,2-氟苯磺酰基乙腈和α-氯肟的多米诺反应可提供异恶唑稠合的4 H -1,4-苯并噻嗪-4,4-二氧化物通过史无前例的无过渡金属一锅添加/环化工艺。可以根据溶剂选择来控制异氧唑啉-1,4-苯并噻嗪-4-氧化物或其前体5-氨基异恶唑的可调合成。所观察到的产物通过(IR,1 H,13 C NMR和HRMS)和物理方法表征。