12.19A straightforward approach to the synthesis ofm-nitrobenzoic acid involves preparation of ben-zoic acid by oxidation of toluene, followed by nitration. The carboxyl group of benzoic acid ismeta-directing. Nitration of toluene prior to oxidation would lead to a mixture of ortho and paraproducts.12.20The text points out that C-1 of naphthalene is more reactive than C-2 toward electrophilic aromaticsubstitution. Thus, of the two possible products of sulfonation, naphthalene-1-sulfonic acid shouldbe formed faster and should be the major product under conditions of kinetic control. Since theproblem states that the product under conditions of thermodynamic control is the other isomer,naphthalene-2-sulfonic acid is the major product at elevated temperature.Naphthalene-2-sulfonic acid is the more stable isomer for steric reasons. The hydrogen at C-8 (theone shown in the equation) crowds the group in naphthalene-1-sulfonic acid.12.21The text states that electrophilic aromatic substitution in furan, thiophene, and pyrrole occurs at
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This note was uploaded on 09/26/2011 for the course CHM 2210 taught by Professor Reynolds during the Fall '01 term at University of Florida.