Monocrotophos

• Azodrin
• Bilobran
• Nuvacron
• 3- Dimethoxyphosphoryloxy -N- methylbut -2- enamide
• O, O -dimethyl- O-( 2-N- methylcarbamoyl -1 -methyl) vinyl- phosphate
• Dimethyl- (E) -1-methyl -2-( methylcarbamoyl ) vinyl phosphate ( IUPAC)

• 2157-98-4 ( unspecified mixture of cis -and trans- monocrotophos )
• 919-44-8 (cis- monocrotophos )
• 6923-22-4 (trans- monocrotophos )

Colorless, flammable solid

Fixed

1.33 g · cm -3

54-55 ° C (trans- monocrotophos )

125 ° C (0.67 microbars )

0.29 MPa (20 ° C)

• Soluble in water
• Soluble in acetone and aliphatic alcohols
• Slightly soluble in mineral oils

Risk

14 mg · kg -1 ( LD50, rat, oral)

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Monocrotophos is an unsaturated chemical compound and an insecticide selected from the group of carboxylic acid amides and phosphoric acid esters.

Production and representation

Since the patent has expired for the connection, monocrotophos is now license-free produced by several companies.

Monocrotophos can be synthesized from diketene. The addition of methylamine is first formed Methylacetoacetamid, which leads to reaction with sulfuryl chloride and subsequent reaction of the product Perkow with trimethyl phosphite to monocrotophos.

The industrial synthesis yields a mixture of cis -and trans- monocrotophos, the cis isomer usually predominates.

Properties

Pure monocrotophos forms colorless crystals. Technical monocrotophos contains at least 75 % of the compound, and is a reddish-brown mixture of liquid and solid components having a melting point between 25 and 35 ° C and a mild ester aroma. It is unstable in the short-chain alcohols and glycols. In water it hydrolyzes slowly at temperatures above 38 ° C it begins to decompose. The isomers cis -and trans- monocrotophos differ not only toxicologically but also in their storage stability.

Use

Monocrotophos is used as broadband and fast-acting insecticide (for example, against Lepidoptera, Homoptera, Coleoptera and mites ). It acts as a cholinesterase inhibitor. In the U.S., the use of potatoes and tomatoes in 1985 and 1988 was generally prohibited. Monocrotophos has not been added to the list of approved facilities in Europe pesticide active ingredients. Thus, there is no authorization of a plant protection product monocrotophoshaltigen in Germany and Austria, and in Switzerland, no such product is approved.

Safety

Monocrotophos is highly toxic, especially for birds ( LD50 of 0.9 to 6.7 mg / kg) and bees.

Related compounds

• Dicrotophos