4511. Glyoxylic Acid

Nomenclature

CAS number: 298-12-4
Oxoacetic acid; formylformic acid; glyoxalic acid; oxoethanoic acid.
C2H2O3; mol wt 74.04.
C 32.44%, H 2.72%, O 64.83%.
OHCCOOH.

Description and references

Occurs in unripe fruit and in young green leaves; has also been found in very young sugar beets. Prepd by heating dibromoacetic acid with some water: Grimaux, Bull. Soc. Chim. [2] 26, 483; Cramer, Ber. 25, 714 (1892); by electrolytic reduction of oxalic acid: Meyer, Ber. 37, 3592 (1904); by the action of Aspergillus niger on calcium acetate, malonic or citric acid: Challenger et al., J. Chem. Soc. 1927, 205, 207. Prepn of glyoxylic acid soln for analytical use: Beilstein vol. III, 594.

Derivative

Hemihydrate.

Properties

Crystals from water, mp 70-75°. Also obtained in anhydr form as monoclinic crystals from water, mp 98°. Obnoxious odor. Strong, corrosive acid. K = 4.6 × 104. Deliquesces rapidly and forms a syrup on short exposure to air. Sparingly sol in alc, ether, benzene. Freely sol in water; aq solns tend to acquire a yellowish tint. Attacks most base metals except certain stainless steel alloys.

Derivative

Monohydrate.

Properties

Crystals, mp ≈50°. Highly hygroscopic.

Caution

Irritant, corrosive.