Provide the systematic name for the following carboxylic acid. Here, to do that, we're going to utilize these steps in terms of naming the molecule before us. So, here's step 1, find the longest carbon chain. This will represent our parent chain, and assign a name according to the prefixes and modifiers. The parent chain should include the carboxylic acid group and a greater number of carbons. Now, if there is a tie between longest chains, choose the chain with more substituents. Alright. So, we're going to find the longest carbon chain. We have to make sure that the carboxylic acid group is part of it. So if we look, this would be the longest carbon chain. We can go this way, or we can go this way. Both would give us the same length for the carbon chain and the same number of substituents. So here, I'm just going to go by the original way, this way.
Now, assign names to all the substituents for step 2. So here, we have a bromine group as a substituent, so this would be bromo. And then here, we have a 3-carbon alkyl group which is an ethyl. Start numbering the chain at the carbon of the carboxylic acid group, so the COOH group. So this would be 1, 2, 3, 4, 5, and 6.
And then steps 4 to 6, we repeat steps from previous naming topics. Mainly, we give numerical locations to the substituents, we make sure that they're named alphabetically in relation to each other, and we make sure we use commas to separate numbers and dashes or hyphens to separate letters from numbers. So here, alphabetically, 'b' comes before 'e'. The bromo is on carbon 3, so 3-bromo. And then we have the ethyl on carbon 4, 4-ethyl. Since the carboxylic acid carbonyl carbon is carbon number 1, we don't have to give it a number designation. So we have a 6-carbon chain which is hexane, but we change the 'e' ending to hexanoic acid here. It becomes 'oic acid', so the name of our carboxylic acid here would be 3-bromo-4-ethylhexanoic acid.
