Hi,
FOAF of SWIX told SWIX about his dream on BS's Benzo Wacker Oxidation. He had 2 dream(s) on it.
In the 1st dream:
1) At T + 0:00
PdCl2 2g (purchased, lab grade, pink crystal)
p-Benzoquinone 150g (FOC from chem supplier, dunno what grade, darkish black sand with little shed of gold)
DMF 300 ml(purchased, lab grade, clear transperant solvent)
Distilled H2O 50ml (FOC from chem supplier)
Color of the mixture turned dark red(almost black) once p-benzoquinone was added.
These were mixed together(in a 1L RBF) and stirred with overhead stirrer for an hour before porceed to add safrole.
2) T + 1:00
Safrole 160g (obtained thru simple distillation @ 238 /vacuum distillation @ 110 and also crystallization, clear transperant like water with nice smell)
DMF 50ml(same batch)
Color of mixture remained same after addition of safrole. Dark red, almost black.
They were mixed together and dripped into the 1L RBF in 40min time.
3) T + 1:40
Finished addition of safrole.
Temperature was monitored constantly, 30 C at this time.
Color of the mixture remained same.
4) T + 5:00
Temperature was about 40 C. Peak.
Color remained same.
5) T + 6:10
Temperature returned to 30 C.
Color remained same.
6) T + 6:30
Hydrochloric Acid solution 1.5L (by mixing 50ml HCL to 1.5 L distilled H2O)
The hcl solution was placed in a 3 L beaker jar(plastic), the black/red mixture from 1L RBF was thrown into the 3L beaker jar. There were some black oily tar produced after the addition.
2x 100 ml DCM washes performed but no organic layer formed, even with help of torch light. So NaOH wash was not performed and the whole stuff was stored aside.
2nd dream:
All purchased chemicals were lab grade. Safrole was obtained thru crystallization using seed from simple distillation @238 C, crystal clear. Distilled water was thru same Chem supply too.
Only doubt was p-benzoquinone, it was FOC from the chem supply. It had no expiry date and the packaging was full of dust, although was packed nicely.
1) T + 0:00
PdCl2 2 g
DMF 300ml
Mixed and stirred for 30min using over head stirrer.
2) T+ 0:30
p-Benzoquinone 150g
Added to the DMF solution and further stirred for 1 hr. The solution turned dark red(almost black) once quinone was added.
3) T + 1:30
Safrole 160g
DMF 50ml
Premixed the Safrole and DMF, then dripped to the dark solution over 1 hr.
4) T + 2:30
Done with Safrole addition.
Temperature was 30 C. Constant stirring.
5) T + 6:30
Temperature @ 40 C, peak.
Color did not change.
6) T + 9:30
Temperature @ 32 C.
Color did not change.
7) T + 10:00
Stopped stirring, temperature @ 31C.
Flooded the safrole solution with 1.5L diluted hydrochloric acid solution(same as dream 1). A lot of black crude oil formed after the mix. Two distinct layers were observed, separated the organic layer. The aqueous layer was washed with 3x 100 ml DCM.
The organic layer was then washed with 2x 150ml NaOH solution(prepare after addition of safrole after T+2:30), NaOH was salt like, 30g dissolved in 270 ml distilled water.
In the 1st NaOH wash(150 ml of NaOH solution), there were 2 layers formed(not very distinctive but visible with help of torch light, and the top layer was seen with shiny little powder with was thought to be hydroquinone.) Top layer was poured off(kept aside). The bottom layer was then washed again with 150 ml of NaOH solution, this time no layer was formed. Strange thing was that in the first wash the top layer present was about 300ml which was more than the 150 ml NaOH poured in. There were a lot of black crude oil, around 100ml.
Question:
i) What is the real color of p-benzoquinone? SWIX believe that even black color one would give some yield. SWIX used TFSE and returned a lot of pictures and all claimed to be ok?
ii) For 2nd dream, can the solution(crude MDP2P) with NaOH solution be distilled even if there was not 2 layers formed?
iii) For the 2nd dream, why was there no different layers formed for second wash of NaOH?
iv) For 2nd dream, if the p-benzoquinone was not the right thing, could it raise the temperature to 40 C(without external heating)?
v) For the 2nd dream, would the crude black oil be of use to turn to MDP2P?
Some bees might have noticed that there is no questions regarding 1st dream, SWIX suspected that there was no MDP2P in it as the temperature returned to room temperature in 4.5 hrs.
Help will be greatly appreciated to answering the questions? thank you.
