# At what carbon position on the purine ring is the NH_2 group of adenine?

Sep 9, 2016

The ${\text{NH}}_{2}$ group of adenine is on position 6.

#### Explanation:

The structure of adenine is

An alternate name is 6-aminopurine.

For historical reasons, the numbering of purines is not systematic but, at least, it is limited to that class of compound and is not used elsewhere.

All we can do is grin and memorize the numbers.