Week of 10/23-10/27
Monday 10/23
Ran TLC of vacuum distilled 8-Bromonaphthalen-1-amine. The distillation cleaned out a lot of impurities but did NOT remove 1-aminonaphthalene.
=
Began 1,8-napthotriazine synthesis at a 2x scale. This is the third, maybe fourth synthesis. n-butyl nitrite was reacted with 1,8-diaminonaphthalene dissolved in ethanol and acetic acid at <15 degrees C. The reaction was warmed to room temperatures and stirred overnight.
=
I worked up a 8-bromo-1-nitronaphthalene, 4x wash with methylene chloride and rotavaped until dry.
Tuesday 10/24
Workup of 1,8-naphthotriazine, triazine product was washed w/ water until filtrate is clear; then dried under aspirator vacuum.
=
Attempted bromination of the 1,8-naphthotriazine under kinetic conditions (T < 25C), the triazine was added to 30 molar equivalents of HBr and activated (halogen/acid washed) copper powder was added as a catalyst. The reaction had a slight foam after catalyst addition, and left to stir for 72 hours at ~21C.
Wednesday 10/25
I used hexylamine to aminate 4-bromo-1,8-naphthalic anhydride into 6-bromo-2-hexyl-1H-benzo[de]isoquinoline-1,3(2H)-dione. This reaction was done for the senior in my lab, so it doesn't correlate with my primary project (8-Bromo-1-nitronaphthalene synthesis).
Thursday 10/26
I worked up the 6-bromo-2-hexyl-1H-benzo[de]isoquinoline-1,3(2H)-dione by adding excess 2M HCl and filtering the salt out. I accidentally screwed this up, thinking I needed the liquid and not the solid, so I added KOH and rotavaped the product. I re-read the procedure and added yet more acid to precipitate the salt out, and then dissolved the precipitate in methylene chloride, rotavaped until dry.
=
Set up another 1,8-napthotriazine synthesis at a 2x scale. This is getting old, and I ran out of n-butyl nitrite with this reaction. Our lab is running low on n-butanol, so alternative alkyl nitrites are needed.
Friday 10/27
I started a second bromination attempt of the 1,8-naphthotriazine. Setup identical to the one done on Tuesday 10/24.
=
THE BIG MOMENT! The bromination from Tuesday 10/24 was ready to be worked up. Sever hundred milliliters of Ammonium Hydroxide (NH3OH) were used to neutralize the acid (pH ~11). Next, the mix was vacuum filtered through a buchner funnel on an aspirator, and the solids were removed. The aqueous layer totaled to well over a liter, requiring a 2L seperatory funnel. ~700mL methylene chloride was used to extract the product, which was then rotavaped until dry. It was a dark purple oil.
Afterword: The NMR machine is still dead. We are out of HBr after the bromination attempts, and I need to make more of HBr. Very optimistic about the reaction progress, this new reaction had a better workup at the cost of being horribly inefficient from an atom economy perspective. I've generated a truly gargantuan amount of waste (for an organic chemist) this week. Since the NMR is dead, I can't determine the identity of the products I've made. A technician did come to fix the machine though. I'll update on NMR repair progress.