Nomenclature of Mono-cyclic Aromatic Compounds There are certain common names for monosubstituted benzenes, which have been adopted by IUPAC nomenclature in many cases. Some of these are given below, with "prefix" names for thatfunctional group in parentheses after them:Benzoic acid Ph-CO2H (carboxy-)Benzaldehyde Ph-CH=O (formyl-) Acetophenone Ph-C(=O)CH3 (acetyl-)Phenol Ph-OH (hydroxy-)Benzenethiol Ph-SH (mercapto-)Aniline Ph-NH2 (amino-)Anisole Ph-OCH3 (methoxy-)Toluene Ph-CH3 (methyl-)Nitrobenzene Ph-NO2 (nitro-)Chlorobenzene (fluoro-,etc.) Ph-Cl (halo-, etc.)If the benzene ring has only one of the above functional groups on it, it is named as shown. For two or more groups present, to name the compound:(1) Decide which group has the highest priority. This is NOT by the Cahn-Ingold-Prelog rules, but by the IUPAC priority order, as given above: a carboxylic acid is the most important, a halo group (~ nitro) the least.(2) Name the compound as the most important structure, with the other groups added using their prefix names in alphabetical order. Note that the lowest priority groups, halogens and nitro, are named only as prefixes. If there is more than one of a given substituent, it is named as a di- or tri-whatever. This holds even if the group is a high priority "given" one; this is a dimethoxybenzene,not a methoxyanisole: (3) Orientation: there are three possible second positions in a ring after the first is assigned. For disubstituted compounds, the ortho-, meta-, para- system can be used: ortho meta para1These are placed as prefixes to the names, with a hyphen between the prefix and the name. They can be either spelled out or abbreviated o-, m-, or p-. They are always pronounced fully, howeverwritten.If there are three or more substituents present, the numbering system must be used. Number the carbons by making carbon 1 that with the highest priority substituent, though the number 1 isn't actually used in the name. Find the second highest priority substituent, and if there are two possible numbers that can be given to its carbon, depending on the direction that one counts around the benzene ring, give it the lower possible number. This then determines all the carbons' numberings. This system can also be used for disubstituted systems, as well as the o-m-p system.Additional Notes: Alkyl groups are named as their usual prefixes (ethyl-, isopropyl-, t-butyl-, etc.). There are many other given names than these, but these are the common ones you will be dealing with.EXAMPLES p-fluorobenzoic acid meta-nitroaniline ortho-methylanisole4-fluorobenzoic acid 3-nitroaniline 2-methylanisole4-chloro-2-fluoronitrobenzene 3-chloro-5-fluoro-4-iodoacetophenoneSome other common names: vinylbenzene is styrene, isopropylbenzene is