Skip to main content

Structural Puzzle 1

Structures of three C7H15N amine isomers: aminocycloheptane, 4,4-dimethylpiperidine, and dimethylaminocyclopentane Three isomeric (C7H15N) liquid amines are found in separate bottles with no labels. We shall refer to these unknowns as A, B & C. These amines are known to be aminocycloheptane, 4,4-dimethylpiperidine & dimethylaminocyclopentane (structures shown to the right). Each of these compounds is slightly soluble in water (ca. 4%), and each dissolves completely in 10% aqueous HCl.
To discover which is which, two chemical tests may be applied to these unknowns:

1. Treatment with cold nitrous acid (HONO).
2. (i) Treatment with benzenesulfonyl chloride (C6H5SO2Cl) in KOH solution.
(ii) Acidification of the mixture obtained from (i).

Isomer Treatment
with HONO 		C6H5SO2Cl
in KOH 		Acidification
of resulting mixture
A
B
C




Once you have conducted your tests, make structural assignments to A, B & C in the boxes following the compound names.

Aminocycloheptane .............
4,4-Dimethylpiperidine ............
Dimethylaminocyclopentane ..

Close this tab to return to the textbook.