Synthesis and ring transformation of substituted
<i>S</i>
‐(1‐phenylpyrrolidine‐2‐ones‐3‐yl)isothiuronium salts to substituted 2‐imino‐5‐[2‐(phenylamino)ethyl]thiazolidin‐4‐ones
Dedicated to Professor Jaromír Kaválek on the occasion of his 65th birthday
专用于米尔·Kaválek教授在他的65之际个生日
Kinetics and mechanism of ring transformation of S-[1-(4-methoxyphenyl)pyrrolidin-2-on-3-yl]isothiuronium bromide to 2-methylimino-5-[2-(4-methoxyphenylamino)ethyl]thiazolidin-4-one
coefficient beta gradually decreases from about 0.7 to almost zero. The value of pKa approximately 10 for the intermediate to base-catalysedtransformation has been found from this dependence. In the N-methylpyrrolidine and triethylamine buffers, the rate-limiting step of transformation is changed into ring opening of In-, and the general-base-catalysed reaction changes into a specific-base-catalysed one