428. The mechanism of aromatic side-chain reactions with special reference to the polar effects of substituents. Part IV. The mechanism of quaternary salt formation

THE REACTIONS OF m- AND o-NITROSTYRENE OXIDE WITH PHENOL1

“…The position of the nitro group in the nitrostyrene oxides has very little effect on the direction of ring opening except in the acid-catalyzed reaction. This behavior is compatible with the concept of a unimolecular route to the primary al- Although the accelerating effect of a nitro group on the rate of the bimolecular reactions of benzyl chloride is not always observed, as in the reaction with pyridine (7), it is reasonable to expect that the acceleration would persist when the nucleophilic species is an ion and not a neutral molecule (7). When the /3-phenethyl chlorides are considered, the nitro group is again found to accelerate the reaction with potassium iodide (8).…”

“…Found: C, 64.65; , 5.19. When the separation of these isomers by fractional crystallization from ethanol-water failed, the mixture was treated with phthalic anhydride and the isolation of both alcohols accomplished (2). Thus, the mixture of isomers (6.0 g., 0.023 mole), phthalic anhydride (7,4 g., 0.05 mole), pyridine (5 cc. ), and dioxane (25 cc.)…”

A Reëxamination of the Hammett Equation.

“…The duality of substituent constants for some electron-attracting substituents (see Section IV, C and D) provides a test for the presence or absence of conjugation of such substituents with the benzene ring. Thus, the appreciable difference between and * for the p-methylsulfonyl group has been interpreted as evi- 18 Here the same group in the meta-and para-positions is counted as two substituents. dence for strong resonance interaction of this group with the benzene ring (36,179).…”

Hyperconjugation.

“…The influence of hyperconjugation on the reactivity of organic compounds was first explicitly recognized by Baker and Nathan (3,9,10) as a result of the study of the reaction velocities of a series of p-alkylbenzyl bromides with pyridine. The velocity of formation of the quaternary salt was assumed to be facilitated by an increase in the ease of anionization of the bromine atom, due to the electron release of the alkyl group.…”