Amines, benzyl, relative rates

In order to probe the effect of the substrate amine structure on this chemistry forming carbamates, a series of reactions were run under identical conditions to those described for Table I using benzyl chloride as the electrophile and tetramethylcyclohexyl guanidine as the co-base. The reaction rates are tabulated as relative rates with the rate for n-octyl amine set as 1. The results are summarized in Table II. 

The second-order rate constants for the reaction of a number of amines with benzyl chloride are tabulated below. Calculate A// and A5 from the data. Offer an explanation for the relative reactivity order for the amines. What trends do you observe in A// with reactivity ... 

This work was continued later on by Menshutkin in Petersburg in 1890, who studied the quaternization of tertiary amines with alkyl halides - a reaction which now is commonly known as the Menshutkin reaction . Menshutkin found, for example, that the reaction rate between triethylamine and ethyl iodide increases with solvent polarity, up to a factor of 742 in benzyl alcohol relative to n-hexane as solvent(3). 

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