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Author: Subject: Tosyl sulfonhydroxamic acid
starlight_
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[*] posted on 8-11-2018 at 00:08
Tosyl sulfonhydroxamic acid


In the paper Synlett 2009, No. 13, pp 2149–2153, Tosyl sulfonhydroxamic acid is synthesised from Tosyl Chloride and Hydroxylamine Hydrochloride in a mixed solvent system.

The paper can easily be found on Sci Hub with DOI: 10.1055/s-0029-1217565

They use Hydroxylamine Hydrochloride in 2x molar equivalent to Tosyl Chloride and this is deprotonated by 3x molar equivalent of MgO.

The workup involves evaporating the reaction mixture to dryness.

Does anyone have a view on why this is safe / will not explode, since I would expect the reaction mixture to contain freebase hydroxylamine?

Perhaps it is an issue of scale - if so does anyone have a suggestion as to how the workup can be modified to make it safe?
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[*] posted on 2-12-2018 at 09:17



Quote:

Does anyone have a view on why this is safe / will not explode, since I would expect the reaction mixture to contain freebase hydroxylamine?


That is a good question. I would assume the same.


Quote:

Perhaps it is an issue of scale -


I don't think so.Hydroxylamine could explode in tiniest amount.


Quote:

if so does anyone have a suggestion as to how the workup can be modified to make it safe?



A bit contradictory what I just said , but wouldn't modify the procedure.
The authors have tried this. Therefore, it should be fine.

However, If you are still concerned about safety, just contact them by email.

or here
http://www.chemicalforums.com/index.php?PHPSESSID=r2lqerr43m...

or on researchgate

This is a hobby chem forum . For very complex problems one not always get satisfactory answers.

You might find this usefull too.

Thermal runaway reaction hazard and decomposition mechanism of the hydroxylamine system

Chemical reactivity hazards have posed a significant challenge for industries that manufacture, store, and handle reactive chemicals. Without proper management and control of reactivity, numerous incidents have caused tremendous loss of property and human lives. The U.S. Chemical Safety and Hazard Investigation Board (CSB) reported 167 incidents involving reactive chemicals that occurred in the U.S. from 1980 to 2001. According to the report, 35 percent of the incidents were caused by thermal runaway reactions, such as incidents that involved hydroxylamine and hydroxylamine nitrate. The thermal stability of hydroxylamine system under various industrial conditions was studied thoroughly to develop an understanding necessary to prevent recurrence of incidents. The macroscopic runaway reaction behavior of hydroxylamine system was analyzed using a RSST (Reactive System Screening Tool) and an APTAC (Automatic Pressure Tracking Calorimeter). Also, computational chemistry was employed as a powerful tool to evaluate and predict the measured reactivity. A method was proposed to develop a runaway reaction mechanism that provides atomic level ofinformation on elementary reaction steps, in terms of reaction thermochemistry, activation barriers, and reaction rates. This work aims to bridge molecular and macroscopic scales for process safety regarding reactive chemicals and to understand macroscopic runaway reaction behaviors from a molecular point of view.

https://pscfiles.tamu.edu/library/center-publications/theses...




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[*] posted on 2-12-2018 at 16:05


Hydroylamine is pretty safe when in solution, the key is to extract any excess hydroxylamine material with acid when you are done, to keep it as the salt once done. You can always mix the sulfonyl chloride and NHOH-HCl and then add the base slowly, or mix the base and RSO2Cl then add the NHOH-HCl slowly. I would likely use pyridine as the base, maybe even TEA, but inorganic solid bases should work, maybe even just CaCO3 or K2CO3.
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[*] posted on 3-12-2018 at 14:33
Silica


Thank you both.

It appears that the hydroxlamine is removed when the post-reaction mixture is filtered through a silica plug.

[Edited on 3-12-2018 by starlight_]
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