Product Name:

Maleic hydrazide

Synonyms:

1,2-Dihydro-3,6-pyradizinedione;1,2-dihydro-6-pyridazinedione;3(2H)-Pyridazinone, 6-hydroxy-;3,6-Dihydroxypridazine;3,6-Dioxopyridazine;3,6-Pyridazinedione, 1,2-dihydro-;6-Hydroxy-2H-pyridazin-2-one;6-hydroxy-3(2h)-pyridazinon

CAS:

123-33-1

MF:

C4H4N2O2

MW:

112.09

EINECS:

204-619-9

Product Categories:

Agro-Products;Amines;Biochemistry;Plant Growth Regulators;Plant Growth Trgulators (Others);Heterocycles;Aromatic Hydrazides, Hydrazines, Hydrazones and Oximes;PLANT GROWTH REGULATOR;Building Blocks;Chemical Synthesis;Heterocyclic Building Blocks;Pyridazines;Pharmaceutical intermediates;Pesticides intermediate

Mol File:

123-33-1.mol

Melting point 

299-301 °C (dec.)(lit.)

Boiling point 

209.98°C (rough estimate)

density 

1,6 g/cm³

refractive index 

1.4610 (estimate)

Fp 

300°C

storage temp. 

Inert atmosphere,Room Temperature

solubility 

4510mg/l

form 

neat

pka

9.01±0.20(Predicted)

color 

White crystalline

Odor

Odorless

Water Solubility 

6 g/L

Merck 

14,5705

BRN 

112223

InChIKey

BGRDGMRNKXEXQD-UHFFFAOYSA-N

CAS DataBase Reference

123-33-1(CAS DataBase Reference)

IARC

3 (Vol. 4, Sup 7) 1987

NIST Chemistry Reference

Maleic hydrazide(123-33-1)

EPA Substance Registry System

Maleic hydrazide (123-33-1)

Hazard Codes 

Xi,Xn

Risk Statements 

36/37/38-40-R40-R36/37/38-68

Safety Statements 

26-36-45-36/37/39-S45-S36/37/39-S26

RIDADR 

UN 3077 9/PG 3

WGK Germany 

2

RTECS 

UR5950000

Autoignition Temperature

707 °F

TSCA 

Yes

HS Code 

29339990

Hazardous Substances Data

123-33-1(Hazardous Substances Data)

Toxicity

LD50 orally in rats: 3800-6800 mg/kg; dermally in rabbits: >4000 mg/kg (Ben-Dyke)

Chemical Properties

Maleic hydrazide is a colorless crystalline solid. Odorless.

Chemical Properties

Maleic hydrazide is a crystalline solid

Uses

Growth regulator used to control the sprouting of potatoes and onions and to prevent sucker development on tobacco, fruits, ornamentals, vines, field crops and in forestry. Also used to control insects in warehouses, storerooms, empty sacks and in animal and poultry houses.

Uses

Maleic Hydrazide is used in plant growth regulator formulations.

Uses

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

Production Methods

Maleic hydrazide is slightly acidic. It is made by treating maleic anhydride with hydrazine hydrate in alcohol.

Synthesis Reference(s)

Journal of the American Chemical Society, 73, p. 1873, 1951 DOI: 10.1021/ja01148a537

General Description

Odorless white solid. Sinks in water.

Air & Water Reactions

Insoluble in water.

Reactivity Profile

3,6-Dihydroxypyridazine can be decomposed by oxidizing agents. 3,6-Dihydroxypyridazine can also be decomposed by strong acids. 3,6-Dihydroxypyridazine forms water-soluble alkali-metal and amine salts. 3,6-Dihydroxypyridazine is slightly acidic and may be titrated as a monobasic acid. Mild oxidation produces a compound which reacts instantly with dienes at -107° F to form crystalline derivatives. 3,6-Dihydroxypyridazine is slightly corrosive to iron and zinc. 3,6-Dihydroxypyridazine is incompatible with pesticides that are highly alkaline in reaction. In the presence of heavy metal and iron, zinc, calcium and magnesium ions, sparingly-soluble salts are formed.

Hazard

Toxic by ingestion. Questionable carcinogen.

Health Hazard

Inhalation of dust causes irritation of nose and throat. Contact with eyes or skin causes irritation. Ingestion has been observed to cause tremors and muscle spasms in test animals.

Fire Hazard

Special Hazards of Combustion Products: Toxic nitrogen oxides are produced.

Agricultural Uses

Herbicide, Plant growth regulator, Fungicide: Banned for use in EU countries. Actively registered for use in the U.S. Maleic hydrazide is a plant growth regulator (sprout inhibitor) and herbicide that is registered for use on tobacco, potatoes, onions, non-bearing citrus, turf, utility and highway rights-of-way, airports, industrial land, lawns, recreational areas, ornamental/shade trees and ornamental plants. Most of the use of maleic hydrazide in the U.S. is on tobacco.

Safety Profile

Moderately toxic by ingestion. Questionable carcinogen with experimental tumorigenic data. Mutation data reported. Can cause chronic liver damage and acute central nervous system effects. When heated to decomposition it emits hghly toxic fumes of NOx See also HYDRAZINE.

Potential Exposure

Maleic hydrazide is a pyridazine/ pyridazinone herbicide, plant growth regulator, and fungicide that is registered for use on tobacco, potatoes, onions, nonbearing citrus, turf, utility and highway rights-of-way, airports, industrial land, lawns, recreational areas, ornamental/ shade trees and ornamental plants. Most of the use of maleic hydrazide in the United States is on tobacco. Banned for use in EU countries. Actively registered for use in the United States

Carcinogenicity

Mice fed up to 3 mg/kg for 320 ‘days showed no carcinogenic effect when sacrificed at 2 years of age. Mice fed 0, 1000, 3200, and 10,000 ppm in the diet in 23 months showed no oncogenic effect. Rats were fed diets providing doses of 0, 25, 500, or 1000 mg/kg. Occasional increases in tumor incidences were seen, but as these were not consistent between the two sexes and did not achieve statistical significance, they are considered not attributable to maleic hydrazide.
Application of maleic hydrazide to the skin three times a week up to a cumulative dose of 300mg was not carcinogenic . Oral treatment of dogs and rats for 17–28 months resulted in no excess cancer in any tissue or organs. Subcutaneous injections of maleic hydrazide in newborn mice produced a very slight increase in liver tumors, although this finding is generally considered negative. A study in which maleic hydrazide was given subcutaneously to mice (55 mg total over 49 weeks) showed no evidence of a carcinogenic response was seen.

Environmental Fate

Soil. The half-life in soil was reported to be 2–8 weeks (Hartley and Kidd, 1987). When maleic hydrazide was applied to muck, sand and clay at concentrations of 0.7 and 2.7, 1.0 and 3.75 and 0.85 and 3.4 ppm, 86 and 100, 87 and 100 and 47 and 67% degradation yields were obtained, respectively (Hoffman et al., 1962).
Plant. Major plant metabolites include fumaric, succinic and maleic acids (Hartley and Kidd, 1987).
Photolytic. In water, maleic hydrazide showed an absorption maximum at 300 nm indicating direct photolysis should occur (Gore et al., 1971).
Chemical/Physical. Reacts with alkalies and amines forming water-soluble salts (Hartley and Kidd, 1987). Decomposed by oxidizing acids releasing nitrogen (Worthing and Hance, 1991). Decomposes at 260°C (Windholz et al., 1983) releasing toxic fumes of nitrogen oxides (Sax and Lewis, 1987).

Shipping

UN3082 Environmentally hazardous substances, liquid, n.o.s., Hazard class: 9; Labels: 9-Miscellaneous hazardous material, Technical Name Required

Purification Methods

Crystallise the hydrazide from water. Dry it at ~100o over P2O5. [Beilstein 24 III/IV 1186.]

Incompatibilities

Dust may form explosive mixture with air. Incompatible with oxidizers (chlorates, nitrates, peroxides, permanganates, perchlorates, chlorine, bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases, strong acids, oxoacids, epoxides. Slightly corrosive to iron and zinc. Maleic hydrazide forms water-soluble alkali-metal and amine salts. It is slightly acidic and may be titrated as a monobasic acid. Mild oxidation produces a compound which reacts instantly with dienes at 277C/ 2 107F to form crystalline derivatives. It is incompatible with pesticides that are highly alkaline in reaction. This chemical is slightly corrosive to iron and zinc. In the presence of heavy metal and iron, zinc, calcium, and magnesium ions, sparingly soluble salts are formed.

Waste Disposal

Consult with environmental regulatory agencies for guidance on acceptable disposal practices. Generators of waste containing this contaminant (≥100 kg/mo) must conform to EPA regulations governing storage, transportation, treatment, and waste disposal. In accordance with 40CFR165, follow recommendations for the disposal of pesticides and pesticide containers. Containers must be disposed of properly by following package label directions or by contacting your local or federal environmental control agency, or by contacting your regional EPA office.

Raw materials

Hydrazinium hydroxide solution-->Hydrazine, hydrate (1:1)-->Maleic anhydride-->1,3-BUTADIENE-->Hydrazine sulfate

Preparation Products

3,6-Dichloropyridazine-->SULFACHLOROPYRIDAZINE-->3(2H)-Pyridazinone, 6-Methoxy-