chloric1 - 13-11-2024 at 09:23
I am aware of preparations of nitro alkanes from silver nitrite. Normally, free nitrous acid reacts with alcohols to produce nitrite esters. But
apparently the silver ion favors nitrogen to carbon bonds from alkyl halides and silver nitrite. My question is why doesn’t the nitrite group
attach itself as a nitrite ester instead?
clearly_not_atara - 13-11-2024 at 16:34
In some sense, this is a result of the solvent. The reaction between AgNO2 and RBr is carried out in diethyl ether, which of course will not dissolve
any alkali nitrite. In fact some nitrite ester is produced, but it cannot undergo the usual destructive side-reaction because ether generally does not
tolerate ionization.
The side reaction, incidentally, occurs roughly as follows:
RHNO2 + NO2- <> NO2H + RNO2- (nitronate)
RNO2- + RONO >> RO- + RNO(NO2) (nitrolic acid)
RO- + NO2H >> ROH + NO2-
But AgNO2 is basically inactive as a base due to strong covalent coordination to silver and the low tolerance of ether to solvate a free ion.