poix (Newbee)
03-07-02 19:40
No 278451
      TMS-Cl/NaBH4 reduction of nitrostyrene  Bookmark   

I would like to know if someone as ever tried it and if he got success, swim dreamed of it with MEPEA nitrostyrene and it didn't work, but he is not very skilled. Another question: the text ../rhodium/chemistry /pictures/tmscl-2.gif has no ref with nitrostyrene, how many eq. of NaBH4 and TMS must swim use? Same as the nitrile or more, I don't know because of the nitro group
(Chief Bee)
03-07-02 20:18
No 278468
      Re: TMS-Cl/NaBH4 reduction of nitrostyrene  Bookmark   

You should use twice the amount of TMS/NaBH4 compared to the nitrile. Don't forget to report your results here.
03-22-02 18:44
No 286461
      Re: TMS-Cl/NaBH4 reduction of nitrostyrene  Bookmark   

I retried it with MEPEA, with more than twice the amount of NaBH4/TMSCl, reaction time 16h, dried glassware before in oven at 150, with CaCl2 tube and it didn't work: I got the same orange brown at end wich turn black when I acidify and that is insoluble. During the reaction I saw some HCl evolution, so my TMSCl was decomposed by water/moisture. I guess that an azote atm is needed and will stick with beaker's method were anhydrous is not a must. Ah yeah and the orange color of nitrostyrene does not disapear when I stop the addition like with beaker's.
(Pioneer Researcher)
03-22-02 22:08
No 286532
      Zn HCl ?  Bookmark   

Do you want to try this very simple rdxn ?

2.5 gr powdered (coffee grinder) DMNS (put the molar eq.)in 20 methanol and 4 ml HCl 36 %(mix methanol and HCl first and let it cool to room temp), put in a water/ice bath and when it is at 4 C add 0.5 grams of Zn dust, when temp descends to 4 C add 1.5 ml HCl, let cool again and repeat till you have added 12.5 C of Zn and 36 ml of HCl, keep rxn cooling with the ice bath at 4-6 C or less 6 hours (only a bit of Zn will reamin in rxn), let melt and wait 8 hours more. Filter if it remains a bit of undissolved Zn, add 40 ml of water, remove with aspirator methanol, wash with three small portions of DCM (add more water if there's no separation), basify with 40 % NaOH, cooling to not let temp go >30 C (it's better to add acid solution to basic solution, then add more NaOH solution till you have no solids, all hydroxides dissolved), extract with toluene, 3 x 18 % v/v, wash with toluene 1x30 % v/v 40 % NaOH, dry 12 hours with 10 % KOH w/v, filter and wash a bit the KOH with toluene that you will add to the filter, concentrate the toluene and crystallize.
Just follow exactly the instructions, you don't need to be very skilled to make this rxn.
I promise you that you will see dissappear the nitrostyrene in the 5 first additions, and a minimum yield of 50 %, though I believe it will be > 70 %. Same procedure with 2,5 DMNS and only 6.25 gr of Zn dust gave 56 %.
If you try it, please post results. Thanks.