Intramolecular sulphonyl-amidomethylation. Part I. Cyclization of benzylsulphonamides
作者:Orfeo O. Orazi、Renée A. Corral、Rodolfo Bravo
DOI:10.1002/jhet.5570230620
日期:1986.11
strong acid media is a synthetically useful route to 3,4-dihydro-1H-2,3-benzothiazine2,2-dioxides III. With insufficient acid strength or reaction time, kinetic products IV and VI are obtained; the latter compounds can be converted into the thermodynamic products III under stronger conditions. The reactions proceed via imine VII or iminium VIII compounds as common intermediates.
在强酸介质中苄基磺酰胺与醛的环化是合成3,4-二氢-1 H -2,3-苯并噻嗪2,2-二氧化物III的合成途径。在不足的酸强度或反应时间的情况下,获得了动力学产物IV和VI。后者的化合物可以在更强的条件下转化为热力学产物III。反应通过亚胺VII或亚胺VIII化合物作为常见中间体进行。
Heteropolyacid as an Efficient Catalyst for Synthesis of 3,4-Dihydro-1H-2,3-benzothiazine-2,2-dioxides
作者:Alicia S. Cánepa、Leandro D. Sasiambarrena、Rodolfo D. Bravo
DOI:10.1080/00397910802219585
日期:2008.7.24
A facile and efficient method for the formation of 3,4-dihydro-1H-2,3-benzothiazine 2,2-dioxides 2, compounds from benzylsulfonamides and formaldehyde is described using heteropolyacids H3PW12O40 and H3PMo12O40 supported on silica as catalysts.
AN EFFICIENT SYNTHESIS OF 3,4-DIHYDRO-1H-2,3-BENZOTHIAZINE 2,2-DIOXIDES USING AMBERLYST 15 AND AMBERLYST XN 1010
作者:Rodolfo D. Bravo、Alicia S. Cánepa
DOI:10.1081/scc-120014987
日期:2002.1
ABSTRACT Resins Amberlyst 15 and Amberlyst XN 1010 are used in the synthesis of 3,4-dihydro-1H-2,3-benzothiazines 2,2-dioxide. Advantages of this new procedure are simple work-up, high yield and selectivity, easy recovery of the catalyst and no waste problems.