Importance of steric effect and evaluation of quantitative structure reactivity relationship (QSRR) in the quaternization reaction of benzothiazoles and phenacyl bromide

✍ Scribed by Bijay Kumar Mishra; Arabinda Sharma; Gopabandhu Behera

• Publisher: John Wiley and Sons
• Year: 1989
• Tongue: English
• Weight: 313 KB
• Volume: 21
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.550210607

✦ Synopsis

The kinetics of reaction of substituted 2-aminobenzothiazoles and phenacyl bromide have been followed conductometrically and in some cases, argentometrically. Both the methods produced almost the same rate constants. Substituents at position 5 of the benzothiazole nucleus behave like para substituents of the benzene ring. A correlation with Hammett up substituent constants has been obtained with a rho value of -1.04. The rate data of quaternization reaction of 4, 5, and 6 substituted 2-aminobenzothiazoles with phenacyl bromide have been correlated with Fk, R b , and V, values by multiple regression analysis with the equation suggested by Williams and Norrington and modified by us. The values are found to correlate well with the equation, log k = -4.4979 -0.4815f;Fh + 0.5933r,Rh -0.0277Vu.