Yesterday, I had me some fun in ye olde lab. Some of the old school kind. And it involved a diazocompound.
I know what you're thinking must have happened if I mention diazo. No, no, rest assured that all flasks are still present and accounted for. There was no reason for two of my grad school professors to show up and chant "You'll blow your nuts off! You'll blow your nuts off!" (Two of my professors went to great lengths a couple of times to try and pound into our thick skulls the dangers inherently built into diazocompounds, like their tendency to go BAM!, and not with powdered sugar). This was an entirely different beast altogether.
All I wanted to do was to convert an amine into a hydroxy group, which I've done by this route maybe two dozen times now. So, yesterday, I took my amine up in glacial acetic acid (as per usual) and I stirred it vigorously under N2 (as per usual) and then I took my sodium nitrite up in water to make an approximately 2M solution (as per usual). When I added the first drop, everything changed color drastically. Usually, it goes from pale yellow to bright yellow as the diazo forms and is replaced by water. This time it turned dark brown/orange. Better yet, it started making a gas that was the same color.
Instantly recognizing it for the bank of death that it was, I acted. Fortunately, from my bigass hydrogenation days, I had a sparge line set up, and I jammed that into the flask and quickly affixed the outlet hose with a pipet which got set in an Erlenmeyer of water. I watched as the Orange Death slowly made its way through the tubes to the water where it harmlessly dissociated into nitric acid. Later, after (somewhat miraculously...it seems) my reaction went to completion, I was smart enough to flush the solution with nitrogen to chase out the rest of the gas before I continued on with the work up. Today, I isolated a beautiful white solid, which is amazing since everything was black and orange (screw you Warsaw Tigers!). The LC\MS even confirmed it was the right stuff.
I'm not sure why this time was different than all the rest. I guess my starting material wasn't as clean as usual (which is true) and that something in there caused the generation of the N2O4. Whatever, no one got hurt or dead (which is most important) and I have a gram of nice, clean material to carry on to further reaction.
Too bad I'm taking a couple of days off and won't get to do anything with it until next week (more on that later).
9 hours ago
2 comments:
There's nothing like a rogue reaction to get your blood pumping!!!!
Amen to that!!!
Post a Comment