Naming amitriptyline by IUPAC [closed]








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Can someone guide me through step by step how amitriptyline is named by IUPAC?
I know the name *per se*, but it is very confusing to me, and I'd like someone to explain it to me. The systematic name is 



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> 3-(10,11-Dihydro-5*H*-dibenzo[a,d]cycloheptene-5-ylidene)-*N,N*-dimethylpropan-1-amine.
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**Note:** As stated in a comment to the question by Loong, the preferred IUPAC name according to the 2013 nomenclature recommendations is:



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> 3-(10,11-dihydro-5*H*-dibenzo[a,d][7]annulen-5-ylidene)-*N,N*-dimethylpropan-1-amin‌​e
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The only change this makes to the analysis it that we can ignore the ‘incorrect’ cycloheptene, because [7]annulen is automatically a cycloheptatriene-type molecule.




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First, let’s separate the name into its fragments. We have:


1. 3-*something*-propane-1-amine
2. *N,N*-dimethyl
3. (10,11-dihydro-*something*)
4. (*something*-5*H*-dibenzo[a,d]cycloheptene-*something*)
5. (*something*-5-ylidene)


I’m going to start with item 4, since that is the main bicycle. Cycloheptene sounds like this molecule:


![Cycloheptene with IUPAC-numbering](https://i.stack.imgur.com/i778l.png)


But the [a,d] and the *dibenzo* is telling us that we have a fused polycyclic unsaturated hydrocarbon, so we will need to add two more double bonds. (Skipping a picture of this step.) *Dibenzo* means that there are two fused benzene rings, and the letters in square brackets symbolise the attachment points. *a* stands for 1,2; d for 4,5 (analogously for other letters). With that, we get a tricyclic compound with many double bonds. However, it is still ambiguous *how* exactly to place the double bonds, we need the information 5*H* — it tells us that the ‘additional’ hydrogen must be at the 5-position. **Beware:** The 5-position *does not* reference the initial numbering we used for fusing the rings; the atoms are renumbered according to the rules for aromatic polycycles: Starting at the top right and going clockwise, *ignoring all bridgehead atoms.* So we get 5*H*-dibenzo[a,d]cycloheptene which looks like this:


![5H-dibenzo[a,d]cycloheptene](https://i.stack.imgur.com/39VMP.png)


Next up, item 3: 10,11-dihydro. This means that the double bond in the seven-membered ring is hydrated, i.e. there is a single bond instead.


![10,11-dihydro-5H-dibenzo[a,d]cycloheptene](https://i.stack.imgur.com/IfTOW.png)


And finally, item 5: 5-ylidene. We are attaching something to carbon 5 *via* a double bond. We’ll get back to that.


Item 1: 3-*something*-propane-1-amine. That’s nice and simple, we’ll first consider propane-1-amine:


![propane-1-amine](https://i.stack.imgur.com/NhwtX.png)


*N,N*-dimethyl (item 2) tells us that there are two methyl groups attached to the nitrogen, giving us the following:


![N,N-dimethylpropane-1-amine](https://i.stack.imgur.com/kAPBf.png)


And now we need to add the entire tricyclo-blurb to the propane’s 3-position using a double bond:


![amitriptyline](https://i.stack.imgur.com/2zjjP.png)


And voilà, there is amitriptylene!


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