Sulfur monoxide (SO) can be considered as a theoretical anhydride for sulfoxylic acid, but it is not actually known to react with water.

[5] Sulfoxylate reacts with formaldehyde to yield a hydroxymethanesulfinate called rongalite: which is an important chemical for dyeing.

It is likely to be formed as an intermediate when hydrogen sulfide is oxidised by living organisms, or in the atmosphere, or anywhere else in the natural environment.

[6] When H2S is oxidised it starts from oxidation state −2, and should then pass through intermediate values of 0 and +2 before getting to well known sulfite at +4 and sulfate at +6.

[7] When sulfide in alkaline conditions is oxidised by air in the presence of nickel ions, sulfoxylate concentration first increases to around 5% and then decreases over several days.

[8] Fender et al. claimed to make "sulfinic acid" (an isomer of sulfoxylic acid) by ultraviolet irradiation on solid sulfur dioxide and hydrogen sulfide in a solid argon matrix, measuring the infrared vibrational spectrum.

[8] Sulfoxylic acid can be made in the gas phase in an electric discharge through a neon, H2, SO2 mixture.

[8] The sulfoxylate ion apparently has an X-ray absorption near edge structure at 2476.1 eV.

This in turn reacts with water forming hydroxide ions and nitric oxide (NO).

[11] When sulfoxylate reacts with hypochlorite, bromine or chlorine dioxide it forms hydrogen sulfite and sulfates.

[11] Dithionite is unstable in a pH 4 solution, decomposing to sulfoxylic acid and hydrogen sulfite.

This sulfoxylic acid reacts with more dithionite to yield more hydrogen sulfite, and some kind of sulfur, and a small amount of thiosulfate.

[1] Salts of sulfoxylic acid that have been claimed to have been made include cobalt, thallium and zinc.

Successfully synthesized compounds include the methyl, ethyl, propyl, isopropyl, n-butyl, n-pentyl, and cholesterol esters, as well as the hemiester para‑(hydroxysulfanyl)­cresol (i.e., 1‑hydroxysulfanyloxy-4‑methylbenzene).

It is a liquid at standard conditions that boils at 74 °C and freezes at -67° In the gas state the molecular bond angle ∠OSO is 103°, with the oxygen-sulfur distance 1.625 Å.

The molecule as C2 symmetry with one methyl group rotated above the plane determined by the OSO atoms, and the other below.