Deactivating groups substitution

The pKa of p-(tiifluoromethyl)benzoic acid is 3.6. Is the trifluoromethyl substituent an activating or deactivating group in electrophilic aromatic substitution ... 

Deactivating group (Section 16.4) An electron-withdrawing substituent that decreases the reactivity of an aromatic ring toward electrophilic aromatic substitution. 

Thus it seems clear that, in the absence of interactions with the reaction medium, SOR groups behave as — R substituents and activate electrophilic substitution. However, they are prone to protonation or at least to act as hydrogen bond acceptors, in which condition they behave as + R substituents, deactivate electrophilic substitution and are metadirecting. 

Para-Substituted Benzoic Acid, Deactivation Groups K Value a... 

The major product is the heteroannular disubstituted derivative, l,l -diacetyl-ferrocene (I), while a very small amount of a homoannular isomer, 1,2-diacetylfer-rocene (II), is also obtained. The first acetyl group therefore appears to deactivate the substituted ring toward further electrophilic substitution, and the second acetyl group preferentially enters the opposite ring. 

The cr+-parameters determined by the application of the Selectivity Treatment of the few data for substitution of the deactivated mono-substituted benzenes offer a preliminary indication of the use of the o-+-constants from the solvolysis study. However, major uncertainties exist for the charged groups. 

Croups, which are considered to be deactivating groups cause substitution to occur in the position s meta (m) to the deactivating group (exceptions are the halogens which arc strongly o and p directors). 

Answer The Br is a deactivating group and will direct electrophilic substitution to the desired position. Thus the -OCHj group should be put on the ring next. Let us use CHaNa which will require the naphthol C. 

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