Hi!
The two last days in the lab has been great. The goal was DON hydrochloride, which almost certanly has been produced. The vacuum pump was at the repair shop so the entire synth was done without it, which proved to be somewhat annoying, but it wasn't impossible.
to the nitropropene:10 gm's of 2,5-dimethoxybenzaldehyde was processed alá Barium with nitroethane to produce about 10 gm's of nice canary yellow crystals of (2,5-dimethoxy-phenyl)-nitropropene. The nitropropene seems to be somewhat less prone to crystallization than the ethene, so after one hour of reaction, and following addition of the GAA, the 10 mL IPA was evaporated and the resultant mixture was put in the freezer. After 10 mins the mixture was very viscious, but the second it was touched with a glass spatula, the whole mess crystallized nicely. This was washed three times with water to remove the methylammoniumacetate.
reduction:Standard LAH reduction in THF. No noted problems. Gave a nice yeild of 5,0 grammes of yellow-tinted DMA freebase. As mentioned there was no vacuum available, so it was not possible to distill it. The DMA was tested with marquis, which turned totally green immediately just like good old 2CB.
The DMA was dissolved in 30 mL's GAA and stored in the freezer untill it was to be used.
Nitration:Half of the DMA was used for the nitration(the other half has quite another fate heh).
10 mL 62% HNO3 which weighted 13,4 g, was mixed with 3,2 mL's of water to produce 13 mL's 50% HNO3 solution. This was placed in a small flask, and submerged in water/ice. A magnet was put into the flask and stirring was started.
16 mL's of the GAA:DMA mixture(30 mL GAA:5 gm's DMA) was dripped into the solution over the course of ten minutes. The GAA was yellowish in color. As the DMA was put into the nitration liquid, it turned more reddish in color(probably some NOx), but no red gas was evolved. When the addition was complete, it was allowed to stand in ice water for an additional 10 min's. This mixture was poured into 100 mL's of ice/water and stirred. The mixture was brownish/orange and resembeled a nice summer cocktail. The mixture was basified(1) and extracted with DCM(2). The DCM was washed with water and then acidified and extracted into water. The water was washed three times with DCM and then evaporated(3). The resultant "not-so-white-and-beautifull-crystals" has not been weigthed yet, but theres between .5-2 gm's(it's hard to estimate). They'll be subjected to recrystallization and following bioassay.
All in all: it's a quite forgiving synthesis(the nitration that is). It's somewhat less hazardous than bromination with elemental bromine. I just cant figure out how the heck the authors from PiHKAL have made nice crystals from one extraction with DCM. The DCM in this case was less than white and nice with the goodies in it...
I'll probably have some more info when the weekend is due
1:
The PiHKAL entry was followed, but it seems unlogical to basify at first. Why not simply wash with DCM a couple of times to remove the grud?
2:
This one should almost be in worst lab mistakes. After adding the "DCM" there was no separation. Even no ugly emulsion?? Thought about that one for 15 mins untill it was realized that it was THF and not DCM that was dumped into the soln
Had to wait 20 mins for the THF to boil of. Read the labels very carefully after that one.
3:
The water phase should just have been basified and put in some DCM which then could be boiled off. Gives nicer results in 99% of the cases. But again, the PiHKAL autors do it this way. I'm beginning to think it's a prekambrium synthesis writeup
Regards
Bandil
