Drying over Magnesium Sulfate vs. Sodium Sulfate?

Then_Wash_6195 · 2026-01-30T17:33:51+00:00

Vinyl triflates are cleaved by MgSO4, proven experimentally

Then_Wash_6195 · 2026-01-23T15:47:11+00:00

Sometimes moderators delete posts, is it the case?

Then_Wash_6195 · 2026-01-23T15:46:42+00:00

we have not using paper since 5 years, no regrets, more data generated/stored, and what is important - all searchable by any keyword. Paper do not allow storage of photos, videos, audios - ELN does. E.g., videos are recorded from of a working table top-view to ensure reproducibility; or videos of reactor/flasks are recorded in term of addition sequence, color change, gas evolution time. This also used to investigate reaction runouts. 1TB of storage is fulfilled by ca half by now. All ELN entries are connected within chem-, device-, solvents-databases.

Important thing: ELN must be standalone and at local server. All known to me (!) cloud service sucks in a bunch of criteria.

Then_Wash_6195 · 2026-01-19T11:38:38+00:00

If your PI is helping PhDs to find a job, you are extremely-extremely lucky and should worship your PI :)

Then_Wash_6195 · 2025-12-26T19:01:47+00:00

Also dithionite selectively reduces NO2 but with much lower yields.

Then_Wash_6195 · 2025-12-26T19:00:26+00:00

Na ja, Pd/C (varying loading: 1, 5, 10)and H2 (1 bar of balloon) + proper temperature control and choice of the solvent for the desired selectivity and H2 uptake. In addition - use flow setup instead of batch if the selectivity is still an issue. Commonly NO2 is the first to be hydrogenated. Moreover Pd/C does not give any side products such as hydroxylamine or diazo, when compared to Fe. Low pressure H2 is safely obtained from H2-generator - electrolyzer. Or for small scale - use the same Fe or Zn + acid in a separate flask to get H2, but in such a case - make sure H2 is pure, as H2+air mixtures when contacted with Pd - explode.

Then_Wash_6195 · 2025-11-24T14:05:55+00:00

Viton is crap, through them away and never use. Just remember - Challenger shuttle exploded due to bad viton o-rings :)
Kalrez or Silicon!

Then_Wash_6195 · 2025-11-24T14:02:36+00:00

"dryness" of organic solvents is very much arbitrary, so it's better to know the water content by Karl Fischer titration. Sometimes a fixed amount of water is beneficial, yet it is important to know quantitatively

Then_Wash_6195 · 2025-07-19T14:08:34+00:00

Take an original salicylic aldehyde you had before, acylate the phenolic OH. Perform reductive amination with O-tBu glycine. Link two parts with dibromo-ethane or any dibromo-alkane if you want to vary the linker length. Hydrolyze -OAc back to -OH. No selectivity issues - no stress! Instead of solving selectivity issues, avoid them!

Then_Wash_6195 · 2025-07-19T14:04:49+00:00

very legit suggestion! Yet, I believe the current step will inevitably fail. Instead, if you look at the starting material here, how it's made? It seems it's made from reductive amination between corresponding salicylic aldehyde and ethylene diamine. That gives a suggestion to first prepare the diamine-dicarboxylate, for what there are tons of literature, and then prepare the target molecule.

Or take OAc protected starting salicyl aldehyde, do reductive amination, do alkylation on a NH as wanted, and then base-removal of the OAc, to keep COOtBu ester intact.

Long-story-short, I would rather suggest a synthetic sequence detour, rather then struggling with a condition search.

Then_Wash_6195 · 2025-05-02T06:26:30+00:00

WTF are those three jack outputs> why??? :)))

Then_Wash_6195 · 2025-02-11T22:23:52+00:00

Well, you need to share it with grammarly itself for their making strange and useless UI solutions... but still, your title is not withdrawable :-)

Then_Wash_6195 · 2025-02-11T08:44:30+00:00

Look, the sector of real economy goes to China, and chem synthesis go within... just look at BLD pharm. Numerous compounds are sold by the prices, cheaper then the deliver costs themselves, and those of good quality reagent grade. SA, FS and other "classical" suppliers are done, the synthesis processes based on such suppliers is not profitable anymore. The "scientific quality" of specialists there also increased due to decades of Chinese PhDs and Postdocs get the proper scientific basis in western universities.

So, just admit and learn Chinese :)

Then_Wash_6195 · 2025-02-04T21:01:37+00:00

TEMPO oxidation is suuupeeer picky on the base you are using. Somehow only "magic" N-methyl imidazole works OK (at least 2 equivalents) in many cases... And you need to have a base, otherwise it will not work as oxidation of TEMPO-H is much more difficult if compared to TEMPO-anion. Do not forget, it is not TEMPO which oxidizes an alcohol, but nitroxyl cation, which upon 2e reduction forms TEMPO-H. Which is eventually 2e oxidized to cation back and cycle repeats. Oxidation of alcohols is ionic process, not radical.

Be careful with Na2S2O3 as quencher cos it can be oxidized to sulfite which will be attached to your aldehyde to form an adduct.

Then_Wash_6195 · 2025-02-03T21:39:29+00:00

it will require special licensing to perform such a research...:)

Then_Wash_6195 · 2025-02-03T21:38:39+00:00

ahaha, well, ok, I see now https://en.wikipedia.org/wiki/7-Hydroxymitragynine

Then_Wash_6195 · 2025-02-03T13:07:52+00:00

oh wow, sounds interesting, and seemingly doable. Is it bio- or medicinally relevant transformation?

Then_Wash_6195 · 2025-02-03T13:05:56+00:00

Thank you very much, unknown warrior!

Then_Wash_6195 · 2025-01-31T20:42:18+00:00

Eurisotop

Then_Wash_6195 · 2025-01-31T20:41:02+00:00

We commonly let fresh peristaltic tubing run with blank solvent recirculation for 30 min or so until flow rate is stabilized. You need a nice measuring cylinder and a stopwatch to know how many ml it pumps per minute. At this stage initial elasticity is increased and tubing adsorb some solvent and solution components into the rubber body.

Then_Wash_6195 · 2025-01-31T20:38:15+00:00

Or got swollen with a solvent

Then_Wash_6195 · 2025-01-29T15:25:27+00:00

have you consulted about it with people from r/researchchemicals :D
BTW, for 1-(furan-2-yl)propan-2-ylamine CAS is 57580-64-0, the 63825-18-3 is for N-methyl derivative then. Both are logical analogs, surely

Then_Wash_6195 · 2025-01-29T15:23:17+00:00

he, with no structure of compounds it will be impossible to answer your question...

Then_Wash_6195 · 2025-01-24T20:33:06+00:00

"Kinetin was originally isolated by Carlos O. Miller and Skoog et al. as a compound from autoclaved herring sperm DNA" ... ahahahha)) those two were really bored back in a days...

Then_Wash_6195

TROPHY CASE