5705. Maleic Hydrazide

Nomenclature

CAS number: 123-33-1
1,2-Dihydro-3,6-pyridazinedione; maleic acid hydrazide; MH; Fazor; Malazide; Regulox.
C4H4N2O2; mol wt 112.09.
C 42.86%, H 3.60%, N 24.99%, O 28.55%.

Description and references

Prepd by treating maleic anhydride with hydrazine hydrate in alcohol: Arndt et al., C.A. 43, 579 (1949); see also Curtius, Foerstinger, J. Prakt. Chem. [2] 51, 391 (1895). From maleic acid and a hydrazine salt of a strong inorganic acid: Harris, Schoene, US 2575954 (1951 to U.S. Rubber). Alternate prepn from hydrazine sulfate and maleic anhydride in aqueous NaOH: Amatsu, Karasawa, C.A. 51, 18014c (1957); from hydrazine hydrate and maleic anhydride in glacial acetic acid: Feuer et al., J. Am. Chem. Soc. 80, 3790 (1958). Has the ability to inhibit growth of plants without killing them: Schoene, Hoffmann, Science 109, 588 (1949). Toxicity data: R. Ben-Dyke et al., World Rev. Pest Control 9, 119 (1970). Review: Massey, Manuf. Chem. 26, 197-200 (1955). Review and chromatographic studies: Fishbein, Chromatography of Environmental Hazards (Elsevier, New York, 1972) pp 161-166. Review of toxicology: R. Ponnampalam et al., Regul. Toxicol. Pharmacol. 3, 38-47 (1983).

Chemical structure

Properties

Crystals from water, dec 260°. Also reported as mp >300° (Feuery). Slightly sol in hot alcohol, more sol in hot water. LD50 orally in rats: 3800-6800 mg/kg; dermally in rabbits: >4000 mg/kg (Ben-Dyke).

Use

Experimentally in horticulture and agriculture. To control suckering of tobacco. In the synthesis of pyridazine.