Consider the following structure:
CH3CHClCH2NH2
Is it 2-chloropropan-1-amine or 2-chloropropan-3-amine
And do I count the carbons from where the Cl starts or from where the NH2 starts?
Thank you for your time.
t's an amine so start counting from the NH2. I would name that as
2-chloroproyl amine
To determine the correct name for the given structure (CH3CHClCH2NH2), we need to identify the numbering of the carbons and the position of the substituents (chloro and amino groups).
In the IUPAC nomenclature, we want to assign the lowest possible numbers to the substituents. Therefore, we need to count the carbons from a starting point that will result in the lowest numbers for both the chloro and amino groups.
In the given structure, we have a CH3 group on one end and an NH2 group on the other end. Since the NH2 group is higher in priority than the CH3 group, we need to prioritize numbering from the end closest to the NH2 group. So, we count the carbons starting from where the NH2 group is connected. This gives us the following numbering:
NH2 - Carbon 1 - Carbon 2 - Cl - Carbon 3 - CH3
Now, we can determine the correct name by observing where the chloro substituent is located in relation to the amino group. From our numbering, we see that the chloro group is on Carbon 2, and the NH2 group is on Carbon 1. Therefore, the correct name for the structure is 2-chloropropan-1-amine.
To summarize, we count the carbons starting from where the NH2 group is connected, and the correct name for the given structure is 2-chloropropan-1-amine.