INTRAMOLECULAR NUCLEOPHILIC PARTICIPATION .6. FORCED CARBOMETHOXY GROUP PARTICIPATION IN SOLVOLYSIS OF 1-(2,6-DICARBOMETHOXYPHENYL) ETHYL BROMIDE

A comparative study has been made of the rates of hydrolysis of the 2,4- and 2,6-dichloro- and 2,4-and 2,6-dicarbomethoxy derivatives of benzyl bromide, the 1-(2,4- and 2,6-dichlorophenyl)ethyl bromides, and the 1-(2,4- and 2,6-dicarbomethoxyphenyl)ethyl bromides in 80 vol % aqueous dioxane. The four disubstituted benzyl bromides react at comparable rates. At 70.7° the 2,4-dichloro derivative of 1-phenylethyl bromide is about one-half as reactive as its 2,4-dicarbomethoxy analog, but 1-(2,6-dichlorophenyl)ethyl bromide is only V120 as reactive as its 2,6-dicarbomethoxy analog. On the basis of an analysis of the electronic and steric influences of the ring substituents (Cl and COOCH3) on the reactivities of these organic bromides, the high solvolysis rate of 1-(2,6-dicarbomethoxyphenyl)ethyl bromide is attributed to a geometric situation which forces intramolecular nucleophilic participation of the carbomethoxy groups in the displacement process. © 1968, American Chemical Society. All rights reserved.