Radiochemical hey that sounds OTC
I think if one had the ability to perform a radiochemical reaction, then its likely they would have an Aldrich account and no problem ordering EtNO2.....
This is my plan:
US pat # 4319059
To a mixture of magnesium methoxide (0.11 mole) and dimethyl sulfoxide (50 ml) a-bromopropionic acid (0.11 mole) was added at 20°C. with stirring. To this mixture a solution of sodium nitrite (0.145 mole) in dimethyl sulfoxide (65 ml) was added at room temperature. Then, the reaction mixture was stirred at room temperature for 6 hours and was neutralized upon addition of diluted hydrochloric acid. Analysis of the reaction mixture indicated more than 99% conversion of alpha-bromopropionic acid and 94.5% yield of nitroethane.
My plan is as follows;
HBr Bromination of Lactic acid (HBr:Lactic Acid 1:1.1mol) to yeild a-Bromopropionic Acid
Then a stoichiometric amount of Mg(MeO)2 will be made in solution, following klutes work on SM
To this Mg(MeO)2 mix, DMSO will be added and the excess methanol will be distilled off (Mg(MeO)2 is unstable so I figure this will be the easiest method)
Then the reaction will proceed as noted hopefully.
I tested the Mg(MeO)2 synthesis yesterday, which worked with my -200mesh Mg, and somewhat dry MeOH, Klute uses an inert atmosphere and his other ridiculous reagents (I wish
), I believe I obtained the desired Mg(MeO)2, however, on standing what I believe was Magnesium methoxide (which klute describes as gel like) was left and turned hard almost chalk like, this is probably die to the excess MeOH evaporating and the Mg(MeO)2 drying out.
Ill post pictures of my Mg(MeO)2 endeavours tonight...
Just out of curiosity can anyone find any holes in my plan?, is there an easier Magnesium salt that could be used? (see the following extract), I assume If the mix is left stir for a longer period, Mg(MeO)2 could be substituted
Taken from SM:
This patent shows an easy route from alpha-bromopropionic acid to nitroethane in excellent yield. The patent also say that Magnesium chloride, bromide or sulfate may be used instead of the magnesium methoxide, but it doesn't say if this affects yields.
The reaction proceeds as follows: In the polar aprotic solvent DMSO, the alpha-bromopropionic acid reacts in an SN2 fashion with nitrite ion to give alpha-nitropropionic acid and bromide ion. The role of the Mg2+ ion in the reaction is to facilitate the decarboxylation (removal of CO2) from the intermediate nitro acid, as it forms a chelate between one of the oxygen atoms on the nitro group and the oxygen anion of the carboxylic acid. The electron-withdrawing nature of the nitro group makes the carboxylic acid group labile, and it can easily be given off as carbon dioxide. If magnesium methoxide is used in place of the other magnesium salts, the carboxylic acid is directly deprotonated, probably making the reaction go even faster.