A student was given the structural formulas of several compoun...

Question

A student was given the structural formulas of several compounds and was asked to give them systematic names. How many did the student name correctly? Correct those that are misnamed.

l. 2-methyl-N,N-dimethyl-4-hexanamine

Accepted Answer

Hello everyone. Let's do this problem. It says a student was asked to give the systematic names for the four different compounds. The names are listed below, determine which is incorrectly named and replace it with the correct name. The four different compounds given are A N ethyl N methyl hexane, three amine B N N die ethyl, five methyl hein three amine C two, ethyl, N propal cyclo hexamine and D two bromo N N dimethyl penan four amine. So let's draw these four compounds and see if when we would name those compounds from the drawings from the structures, if they match the names that are given to us. So drawing compound A from the name given to us. I like to start drawing from the root name. So hex and tells me we have a six carbon chain. So let's draw six carbon chain, 123456 carbons and a zigzag shape. And let's number those carbons from left to right. on carbon three, we have an amine group. So we'll write NH 2. But then our substituent groups say N ethyl N methyl. So that means we don't have hydrogens on the nitrogen. Instead we have an S and a methyl group. So we can draw me and ethyl group. OK. So that is our compound. And let's see, our nitrogen is the only substituent group. So it has numbering priority. This is the correct Iupac name for this compound. So compound A has the correct systematic name. Let's go on to compound B, we have N N di ethyl, five methyl hein three amine. So starting with that route, Hep that tells me we have a seven carbon chain, 1234567 carbons in a zigzag shape. I'll number it from left to right again. 1234567, adding the substituent groups, we have three amine. So NH 2 on that carbon three and then we have five methyl. So a methyl group on carbon five and N N die ethyl. OK. So we can remove these two hydrogens from the nitrogen and replace those with two ethyl groups. So those are two carbon chains, 22 carbon chains, right? Ok. So let's see if this is correct. We have two substituent groups. Our am mean group is highest priority in numbering, which is why it becomes part of the root name and our methyl group, our ethyl group is listed before the methyl group. Yeah, that looks correct. So part B is also the correct systematic name. Let's go to compound C. We have two ethyl, N propal cyclo hexamine. So hex means six carbons, but it's also cyclo, he, so we have a six membered ring. So we'll draw a six membered ring and the root says cyclo, hex, an amine. So let's add an amine to the ring. So we'll add NH 2 here and it doesn't matter which carbon, right? It's the only we start numbering closest to the nitrogen anyways. And let's add are substituent groups. Well, actually we have to number the ring first. So starting with that amine, the carbon with the amine, I'll number one through six clockwise. Now adding our substituent groups, two ethyl. So we add a two carbon chain to carbon two and we have NRO so I'll remove one of those hydrogens and draw a propal chain, which is a three carbon chain on that nitrogen. 123. All right. So let's see. Our numbering starts at our nitrogen. Our ethyl group is listed before the proble group. So that's listed in alphabetical order. That is the correct name for this compound as well. So it looks like d is probably going to be incorrectly named. So let's draw it and see what we come up with. We have the root name Pentamine. So that is a five carbon chain. I'll draw those zigzag 12345 and I'll number that chain from left to right, 1, 2, 3, 4, 5. Now we have four amine. So adding N H two to carbon. Number four, I have N N dimethyl. So I'll replace those two hydrogens with two methyl groups and we have two bromo. So on carbon number two, we have a bromine atom. Hm. Well, I notice that the nitrogen group or the amine group rather has less priority in numbering than the bromine. Right. Bromine has is on carbon number two and the immune group is on carbon number four. But in a means they get the highest number priority. So this is actually indeed the incorrect name. We just simply have to renumber our chain. So the structure would look like this. So renumbering our carbon chain starting from the right side instead 1, 2, 3, 4, 5, then the correct name would simply be 4 Bromo 2. Sorry, let me redo that for bromo, N N dimethyl tan two amine. OK. So let me rewrite that up at the top. So compound D has the incorrect name and the correct name is for bromo, right? We still list the bromine first because we list in alphabetical order those meths are still on the nitrogens. So N N dimethyl tan and that, I mean is now on carbon two. So tan to amine. So the correct name altogether is for bromo, N N dimethyl tan, two amine. That's it for this problem. I hope this video is helpful and thank you for watching.

A student was given the structural formulas of several compounds and was asked to give them systematic names. How many did the student name correctly? Correct those that are misnamed.
l. 2-methyl-N,N-dimethyl-4-hexanamine

Key Concepts

IUPAC Nomenclature

Functional Groups

Substituent Naming

Watch next