Translation of the german article by GarageChemist
I acquired both references.
The first one contains a simple preparation of formaldehyde sulfoxylate, the second one only of benzaldehyde sulfoxylate.
You only want the preparation of formaldehyde sulfoxylate, right?
So here's an english version of the relevant parts:
There are previous claims to the action of formaldehyde upon hydrosulfurous acid in the english patent 5867 1903. It claims the action of formaldehyde
upon sodium hydrosulfite in neutral and acidic solution in order to achieve a preservation of the hydrosulfites for etching purposes. It has been said
that such a preservation occurs when sodium hydrosulfite (= dithionite, I think) with such an amount of formaldehyde as can be bound. The claimed
product has the formula 2 CH2O*Na2S2O4, crystal water disregarded.
I (meaning the author of the german paper) have now found that a very different reaction occurs when 1 mol formaldehyde acts upon 1 mol hydrosulfite
in the presence of NaOH.
If 1 mol sodium hydrosulfite-solution is shaken with 1 mol NaOH-solution and 1 mol formaldehyde, an exothermic reaction occurs, and the reduction
potential of the solution towards indigo carmine solution in the cold disappears after some time.
If this solution is now mixed with an equal volume of alcohol under cooling, neutral sodium sulfite precipitates.
The alcoholic solution gives a syrup upon evaporation in vacuum which solidifies to an often slightly yellow mass upon standing for some time.
The product such obtained has been recrystallized from water, in which it is extremely soluble, as well as from hot ethanol. In the first case
prismatic crystals are obtained, in the second case large silvery leafs.
The analysis of those gave values fitting for the formula NaSCO3H3* 2 H2O.
This compound is therefore identical to the "formaldehyde- sodium sulfoxylate" isolated in a different way by Reinking, Dehnel and Labhardt (2) from
BASF and Baumann, Thesmar and Frossard (3).
The reaction proceeds according to the equation
CH2O + Na2S2O4 + NaOH ----> NaSCO3H3 + Na2SO3.
(blah blah)
It is resistant against alkali and melts at 62°C.
Its solution gives no precipitate with barium chloride or calcium chloride, contrary to hydrosulfite or formaldehyde bisulfite, but sparingly soluble
salts with barium hydroxide or calcium hydroxide.
With NaOH, a double salt seems to form which has a higher solubility than the monosodium salt.
It is obtained as a syrup form the solid monosodium salt by addition of NaOH solution, or when more than 1 mol NaOH is used in the preparation of the
latter.
(some stuff about the barium salt)
With bisulfite, formaldehyde sulfoxylate forms sodium hydrosulfite (1).
In crystalline form, the latter is obtained by dissolving 1 part of the formaldehyde sulfoxylate in 1 part water and adding 3 parts sodium bisulfite
solution at 38- 40°C. After standing for 0,5-1 hour, sodium hydrosulfite begins to crystallize as the dihydrate:
NaSCO3H3 + 2 NaHSO3 -----> Na2S2O4 + NaHSO3*CH2O + H2O
With CaCl2, the solution of this regenerated salt forms the characteristic calcium salt.
(blah blah)
Analogous to the formaldehyde derivative, the other aldehyde-sodium sulfoxylates are obtained.
While the derivatives of the fatty aldehydes are easily soluble in water, the benzaldehyde derivative is sparingly soluble.
It crystallizes out if a 40°C warm sodium hydrosulfite solution is shaken with 1 mol NaOH and 1 mol benzaldehyde.
The analysis gives values fitting for the formula NaSO3C7H7.
The benzaldehyde derivative is not decomposed by NaOH at room temperature, contrary to the benzaldehyde bisulfite adduct.
In 2 mol NaOH it dissolves and can be reprecipitated by addition of acid.
Please post this version in the appropriate thread so that the whole community profits from it.
I can post the german article from which I translated this there if you wish.
Regards, Stefan |
