262 ARENES AND AROMATICITY 11.25(a) There are three isomeric nitrotoluenes, because the nitro group can be ortho, meta, or para to the methyl group CH trotoluen m-Nitrotoluene p-Nitrotoluene (b) Benzoic acid is CH CO, H. In the isomeric dichlorobenzoic acids, two of the ring hydrogens of benzoic acid have been replaced by chlorines. The isomeric dichlorobenzoic acids are COH COH COH Cl Cl 2.3-Dichlorobenzoic 2, 4-Dichlorobenzoic 2. 5-Dichlorobenzoic COH CO,H COH 2. 6-Dichlorobenzoic 3, 4-Dichlorobenzoic 3.5-Dichlorobenzoic The prefixes o-, m-, and p- may not be used in trisubstituted arenes; numerical prefixes are used. Note also that benzenecarboxylic may be used in place of benzoic. (c) In the various tribromophenols, we are dealing with tetrasubstitution on a benzene rin Again, o-m-and p-are not valid prefixes. The hydroxyl group is assigned position 1 because the base name is phenol. OH 2.3.4-Tb 2,.5-Tribromophen 2.3, 6-Tribromophenol OH B1 Br 2,4,5-Tribromophenol 2, 4, 6-Tribromophenol 3, 4-5-Tribromophenol Back Forward Main Menu TOC Study Guide Toc Student OLC MHHE Website11.25 (a) There are three isomeric nitrotoluenes, because the nitro group can be ortho, meta, or para to the methyl group. (b) Benzoic acid is C6H5CO2H. In the isomeric dichlorobenzoic acids, two of the ring hydrogens of benzoic acid have been replaced by chlorines. The isomeric dichlorobenzoic acids are The prefixes o-, m-, and p- may not be used in trisubstituted arenes; numerical prefixes are used. Note also that benzenecarboxylic may be used in place of benzoic. (c) In the various tribromophenols, we are dealing with tetrasubstitution on a benzene ring. Again, o-, m-, and p- are not valid prefixes. The hydroxyl group is assigned position 1 because the base name is phenol. 2,4,5-Tribromophenol OH Br Br Br 2,4,6-Tribromophenol Br Br OH Br 3,4,5-Tribromophenol Br Br OH Br 2,3,4-Tribromophenol OH Br Br Br 2,3,5-Tribromophenol Br OH Br Br 2,3,6-Tribromophenol Br Br OH Br Cl Cl CO2H 2,6-Dichlorobenzoic acid 3,4-Dichlorobenzoic acid CO2H Cl Cl 3,5-Dichlorobenzoic acid CO2H Cl Cl 2,3-Dichlorobenzoic acid CO2H Cl Cl 2,4-Dichlorobenzoic acid CO2H Cl Cl 2,5-Dichlorobenzoic acid CO2H Cl Cl CH3 NO2 o-Nitrotoluene (2-nitrotoluene) CH3 NO2 p-Nitrotoluene (4-nitrotoluene) m-Nitrotoluene (3-nitrotoluene) CH3 NO2 262 ARENES AND AROMATICITY Back Forward Main Menu TOC Study Guide TOC Student OLC MHHE Website