7893. Protocatechualdehyde

Nomenclature

CAS number: 139-85-5
3,4-Dihydroxybenzaldehyde; 3,4-dihydroxybenzenecarbonal; protocatechuic aldehyde; rancinamycin IV.
C7H6O3; mol wt 138.12.
C 60.87%, H 4.38%, O 34.75%.

Description and references

Prepn from catechol: Reimer, Tiemann, Ber. 9, 1268 (1876); Tiemann, Koppe, ibid. 14, 2015 (1881); from vanillin: Tiemann, Haarmann, ibid. 7, 620 (1874); from veratric aldehyde: Dreyfus, DE 193958; Frdl. 9, 161 (1908-10); from piperonal: Hoering, Baum, Ber. 41, 1914 (1908); Barger, J. Chem. Soc. 93, 563 (1908); Buck, Zimmerman, Org. Synth. coll. vol. II, 549 (1943).

Chemical structure

Properties

Platelets from water or toluene. Dimorphic. Dec 153-154°. pK (25°) 7.55. Soly in water (g/100 ml): 5 (20°); 33 (99°); in ethanol: 79 (78°). Freely sol in ether.