|標題:||Rhodium-Catalyzed Regioselective Synthesis of Isocoumarins through Benzothiadiazine-Fused Frameworks|
|作者:||Dalvi, Prashant B.|
Kulkarni, Manohar V.
Department of Applied Chemistry
|摘要:||An unprecedented two-step, one-pot synthesis of benzimidazothiadiazine 5,5-dioxides is presented. Reaction condition based regioselectivity has been achieved where fused benzimidazo[1,2-b][1,2,4]thiadiazines are exclusively formed under thermal conditions, whereas benzimidazo[2,1-c][1,2,4]thiadiazines were created only under microwave irradiation. The salient features of this protocol include a regioselective sulfonylation of 2-aminobenzimidazole with o-halo sulfonyl chlorides followed by N-C bond formation. The acid forms of these fused regioisomers have been used to introduce novel guanidine containing isocoumarin frameworks.|