OK, tey to be more clear when you write, so we can help, that is help ... you use most of your knowledge and we give hints, that's how this board works:
The product should be sth like diazepam,
That doesn't mean anything. Check your spelling, and use the real word.
and can you suggest what is that spot in tlc
No. I can't. And I also don't want to do your work for you. So no, I won't.
which pervades
per·vade:
verb
1. (esp. of a smell) spread through and be perceived in every part of.
2. to become diffused throughout every part of Sorry, but this word you used is meaningless here. Try again. Ask what you want, so you can understand what you're asking for, and see if maybe you're asking for too much from us.
or in general, which compounds can show a spot like this
,
In general, no I can't do this. There's nothing general about this reaction, and nothing specific about a particular spot. If you've made the product, and you see its impure and you want to conclude that its decomposed, then you have to show how it happened.
unfortunately I don't have any spectrum at this stage
I figured. So, why not begin this problem by drawing the structure of your desired product, and your possible contaminant?