My student sent a labeled compound for CHN analysis. Her data came back all wrong. I remembered (in the dim recesses...) that when doing CHN analyses for deuterated compounds, you have to do something different. But I have no idea what it is. But, technology has advanced in the intervening years, so I had chemdraw automatically calculate numbers.
Chemdraw calcd for C14H15D6NO2: %C: 69.67, %H: 11.27, %N: 5.80
Chemdraw calcd for C14H21NO2: %C: 71.46, %H: 8.99, %N: 5.95
Found: %C: 69.50, %H: 8.42, %N: 5.46
we know the compound is pure, so were are basically trying to remember how to massage the data so that it is right. Chemdraw apparently does NOT do it right?