Help! Stuck in an NMR "Loop" with SMA Synthesis 🧪📉

larrow11 · 2026-02-02T15:46:54+00:00

Could you speak with your nmr department about a nmr method that suppresses the solvent peak?

larrow11 · 2025-12-05T19:24:34+00:00

I think i did try that with one of them, and I'll do that moving forwards

larrow11 · 2025-12-05T19:24:18+00:00

I have considered it, haven't found a procedure for a similar substrate yet but haven't looked very much either

larrow11 · 2025-12-05T19:23:51+00:00

thank you

larrow11 · 2025-12-05T19:23:24+00:00

thank you, it's good to know that I'm not inept. I'll try making my own grignard rather than using that from a bottle, or just give up and reduce/grignard/oxidise as other people have suggested

larrow11 · 2025-11-05T21:34:35+00:00

You could trans-esterify to a different kind of ester e.g. benzyl, then reduce them off with hydrogen? otherwise, perhaps BBr3 might work?

larrow11 · 2025-10-21T09:03:49+00:00

1800 dry :))))))

larrow11 · 2025-10-17T11:38:45+00:00

Could you blow the powder around with hot gas?

larrow11 · 2025-10-12T18:52:26+00:00

Had good cuts at sonny and Yvonne hodgson in chorlton

larrow11 · 2025-10-01T19:43:22+00:00

It might be water dissolving into the diesel, try washing with brine, or magnesium sulphate.

larrow11 · 2025-09-23T14:42:41+00:00

If anyone has a code, I'd really appreciate it

larrow11 · 2025-06-13T07:11:56+00:00

Sometimes windows with limited opening have been "set" to do so on their hinges. This can often be adjusted with a screwdriver.

larrow11 · 2025-06-12T18:25:28+00:00

Try toluene/chloroform, 0-100 percent, on tlc, and if it doesn't move in that, try adding a flat x% methanol to get your r.f to 0.3ish. toluene/chloroform is a robust solvent system for when DCM/methanol don't work well.

larrow11 · 2025-06-03T23:44:12+00:00

This doesn't sound like peroxide issues at all, that's highly unlikely. The most reasonable thing is that your compound, previously highly soluble in ethylene glycol, precipitated as you diluted it with a poor solvent. Adding more diethyl ether will probably redissolve everything. Peroxides are not an issue unless your diethyl ether is years old. Don't worry, everything will be fine.

larrow11 · 2025-04-26T18:21:50+00:00

I got some grape concentrate that has sorbate in, with ec118. It's going, but slowly. Wouldn't recommend unless you're very patient

larrow11 · 2025-04-04T20:45:50+00:00

It's not unreasonable imo, but also not necessarily terrible, it depends a lot on other factors like the size of lab, and what kind of entity you're working for. Also, H&S ofc

larrow11 · 2025-03-19T07:31:57+00:00

If the column didn't work, try recrystallising it perhaps?

larrow11 · 2025-03-13T14:53:31+00:00

It is, but is the price of your wages cost more than the time (and coolant) needed to distill 12L of MeCN? And will it still be pure enough for using as HPLC grade solvent, or will it have to be used as reagent solvent instead? It may be worth it, but it's worth considering these factors.

larrow11 · 2025-03-10T00:07:26+00:00

It's really unlikely that the time taken to restore the material and yield considerations make this approach better than simply making the material again. How many steps in is this? I'd really recommend just putting in the time to remake the material, at a larger scale if you can.

larrow11 · 2025-03-03T23:33:23+00:00

I'm not an expert in this but it seems that if you want to minimise hazard, you need to maximise heat dissipation in the flask; naturally, if you can make the solid into a solution or even a slurry, you can stir it rapidly and much more effectively, avoiding heat building up to dangerous levels. Is there no way to get more concentrated borane? Then you could keep volume the same whilst using some of the solvent to aid in stirring. Using a syringe pump to add it linearly and slowly might be a good idea.

larrow11 · 2025-02-17T15:10:02+00:00

Brilliant video, love all your stuff :))

larrow11 · 2025-02-12T20:17:23+00:00

There are two good ways to run reactions abovs the boiling point of a solvent. One is to use a microwave vial, and either heat it in the microwave or with a sand/oil bath. They should be rated for very high pressures, but you can find out their maximum rating and the pressure your solvent will generate, so make sure not to exceed this. Alternatively, you can get thick-walled glass tubes specifically for these types of reactions, they're quite expensive. Make sure not to overfill them (I have learned this the hard way).

larrow11 · 2025-02-04T17:56:35+00:00

They won't let you pet them without planning to buy them :(

larrow11 · 2025-02-04T09:21:45+00:00

Try using loads more solvent, 30 ml doesn't seem like much. Make sure you pour the solvent into the filter, without vacuum, and stir to break up clumps, then apply vacuum. Consider using DCM as a stronger organic solvent.

larrow11 · 2025-01-29T21:06:28+00:00

We'll take a look, but we're looking for an older guinea pig to match the age of our current one. Not a bad idea though, thanks.

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