137351-56-5Relevant academic research and scientific papers
KINETICS AND MECHANISM OF CYCLIZATION OF N-(2-METHOXYCARBONYLPHENYL)-N'-METHYLSULFONAMIDE TO 3-METHYL-(1H)-2,1,3-BENZOTHIADIAZIN-4(3H)-ONE 2,2-DIOXIDE
Kavalek,Jaromir,Machacek, Vladimir,Sedlak, Milos,Sterba, Vojeslav
, p. 1701 - 1710 (2007/10/02)
The cyclization kinetics of N-(2-methoxycarbonylphenyl)-N'-methylsulfonamide (IIb) into 3-methyl-(1H)-2,1,3-benzothiadiazin-4(3H)-one 2,2-dioxide (Ib) has been studied in ethanolamine, morpholine, and butylamine buffers and in potassium hydroxide solutions.The cyclization is subject to general base and general acid catalysis.The value of the Broensted coefficient β is about 0.1, which indicates that splitting off of the proton from negatively charged tetrahedral intermediate represents the rate-limiting and thermodynamically favourable step.In the solutions of potassium hydroxide the cyclization of dianion of the starting ester IIb probably becomes the rate-limiting step.
