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Oxford Chemistry Students and Applicants

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As far as the codeine in the co-codamol is concerned, just take morphine, treat with sodium bicarbonate, then one equivalent of methyl iodide. Simple :biggrin:

Making the morphine itself is trickier, but we definitely took it apart for a tute once...

Reply 201

Turdburger

ixivxivi

Hah! yes, I was going to say. We did (as a sort of thumbed nose to your thread) actually have a good lecture today, in which the lady was talking about vulva mutants in worms: you get a multi-vulva worm, which sounds disturbing enough, and then you get a vulva-less phenotype, which grows up perfectly happily, until it sexually matures and self-fertilises. The eggs, which can't be laid, then hatch inside the parent and eat their way out. Then the happy little parenticidal kids grow up and repeat the whole cycle.

I could do an "fun bioch fact of the day", to counter the chemistry drear, although I think I would run out pretty quickly...

I literally just got told about that by my gf. Biochemists are scary and kind of evil

Reply 202

Turdburger

cpchem

Of course, if tarnishedpenny or turdburger now come along and point out that I could've done that lot in about four steps, I may have to throw myself out of the window. I'm sure there's room for improvement, though.

Idea: coupling the amine to the other arene ring is almost crying out for a Buchwald-Hartwig...

Ive got a 8 step reaction.

Starting with Toluene.

1)NO2 -- get para isomer (which dominates cf ortho)
2)Sn/HCl
3)Sandmeyer -- drive to get 2 cl at each ortho position to nh2
4) KMNO4 then H+ -- decarboxylation
5) Ph-Br and BuLi
Now you have Ph-NH-Ar where Ar is 2 chlorides ortho
6)O(CO.CF3)2 -- protecting group on Nitrogen so doesnt attack the acyl chloride in step 7
7)H-COCl ALCl3 -- Chlorines deactivating so goes on other ring -- ortho directing so ends up there.
8) Strong OH- gets rid of the protecting group.

Reply 203

Turdburger

That counts as A+H revision :tongue:

Reply 204

cpchem

Step 3 - I'm not entirely sure how you're doing that Sandmeyer, with a free amine in place? That's just going to give you an azo-dimer.
Step 5 - PhLi is not going to attack N - the polarity is the wrong way around... you need to disconnect to the other pair of synthons (if you like retro-chat)
Step 7 - the carboxy group is not directly bonded to the ring - there's a methylene in the way.

Reply 205

cpchem

From phenol:
1) fuming sulphuric acid, heat to give para-sulphonic acid.
2) conc. nitric and sulphuric, then tin/hydrochloric to give an amine ortho- to the OH.
3) sodium nitrite, conc. hydrochloric, then copper(I) chloride - Sandmeyer gives Cl ortho- to OH.
4) nitrate and reduce again (à la step 2) to give an amine on the other side, then diazotise, Sandmeyer with CuCl.
5) remove sulphonic acid with dilute sulphuric and heat.
6) treat with triflic anhydride - (F₃CSO₂)₂O in toluene and aqueous potassium phosphate to give ortho-dichlorophenyltriflate - product A.

From ortho-bromoaniline (can make from aniline, via sulphonation, diazotisation, Sandmeyer, desulphonation):
a) treat with mangesium turnings in dry THF or diethyl ether, then add ethylene oxide
b) dichromate oxidation with sulphuric acid to form carboxylic acid. Protect as ethyl ester with EtOH and hydrochloric - product B.

Then combine A and B with palladium tetrakis, dppf and sodium t-butoxide (Buchwald-Hartwig) - couples amine to aryl triflate directly, with loss of triflate. Hydrolyse ethyl ester with sodium hydroxide, then acid workup.

Much more efficient :biggrin:

Reply 206

Turdburger

oops i missed a step out. around i need a 4.5 and 5 is different.

Reply 207

cpchem

EierVonSatan

You should see the disconnection I'm having to do :cry:

For diclofenac:

1) aniline + fuming H2SO4/heat ---> NH2-C6H4-SO3H
2) NH2-C6H4-SO3H + NH3 ---> NH2-C6H4-SO2NH2
3) NH2-C6H4-SO2NH2 + HCl/H2O2 ---> diortho sub. aminosulfonamide
4) remove the SO2NH2 grp with H2SO4/heat
5) bromobenzene/CuO/Goldberg reaction ---> Ph-NH-Ar (Ar = Ph having 2 ortho chlorines) [OR Ullmann-type amination]
6) ClCH2COCl + amine --> Ph-N(COCH2Cl)-Ar
7) Intramolecular freidel crafts alkylation with AlCl3 at ortho position
8) amide hydrolysis with NaOH ---> diclofenac sodium salt

Do you have some sort of chemistry-detection device, EVS? :tongue:

Reply 208

cpchem

EierVonSatan

Of course, it's called a nose (or e-nose in this regard) :biggrin:

Hehe... our chem chat was evicted from the main Oxford chat thread, although leotard-chat seems still to be allowed... :confused:

Reply 209

cpchem

EierVonSatan

I see

So have you decided on working for Veronique next year? I think you said you were interested...

Yeah, she was my first choice, which all worked out, thankfully :biggrin:

Reply 210

cpchem

EierVonSatan

Awesome, I know one of her PhD students, he did his 4th year project in my group. Small world, academia.

Yeah, can't wait to start. Just the small obstacle of finals, first. Even though half of my papers are organic, it's still dragging...

Reply 211

cpchem

Hmm... it's just those five days... those six papers *shudder*

Reply 212

gruffyddd

cpchem

Yeah, she was my first choice, which all worked out, thankfully :biggrin:

You must be interested in fluorine chemistry then I take it. From what I've heard from one of the Mertonites, she is a very good mentor. But I did find her lecturing style quite intimidating to begin with. Still she was recently made a Professor, so her research must be getting noticed.

Reply 213

cpchem

gruffyddd

She really sold me on her research when I went to see her - she's very enthusiastic. Who are you working for next year? Someone in the PTC-hell, I presume? :tongue:

Reply 214

Turdburger

cpchem

She really sold me on her research when I went to see her - she's very enthusiastic. Who are you working for next year? Someone in the PTC-hell, I presume? :tongue:

You have to admit though, despite Physical being the subject of the devil, it very much looks like they have an easier time in 4th year.

Im probably going to take the middle ground. I hate organic labs and I hate physical the subject. Inorganic ranks middle in both -- so ill probably go with that.

Reply 215

cpchem

Turdburger

This is the kind of view that makes inorganic part IIs massively popular.

Reply 216

cpchem

Athena

Leotards are not actually a degree subject at Oxford, ergo talking about them is procrastination. Talking about chemistry, ie your degree, in the chat thread, is not procrastination :p:

Yeah, but look how popular our thread is... everyone loves chemistry :biggrin:

Reply 217

gruffyddd

cpchem

Someone in the PTC-hell, I presume? :tongue:

Hah hah, actually I wish it were a joke, but the PTCL truly is a depressing place to be. Claire Vallance (our tutor this year) told us that once upon a time physical part II's used to be more popular (though still less so than inorganic/organic). The year the CRL opened there was a sizeable increase in the inorganic/organic numbers, because most of their groups were leaving the ICL/DP and moving into the palatial surroundings of the CRL. When this was discussed in one of the PTCL meetings, some of the older professors couldn't believe that certain students might take that into account in their part II choice.

Anyway I'm going to be working for John Foord, who is one of the few physical professors to have his lab situated in the CRL :biggrin:

. His general research theme is surface chemistry, which is physical enough for me to enjoy it, and unlike most of physical chemistry research it has some real world applications!

I'm quite surprised that his group and surfaces in general isn't more popular, given all the cool things like nanotechnology, catalysis etc he talked about in his Michaelmas term lectures. But very few people attend the surfaces option lectures - even fewer I'm guessing than go to the chemical biology ones.

I'm not sure what sort of project I'll be working on yet, but if it involves using any of the expensive looking equipment featured on his website, I'm sure I'll be happy. :yep: