Monolinuron

Structural formula
General
Surname	Monolinuron
other names	3- (4-chlorophenyl) -1-methoxy-1-methylurea
Molecular formula	C 9 H 11 ClN 2 O 2
Brief description	colorless crystals
External identifiers / databases
CAS number 1746-81-2 EC number 217-129-5 ECHA InfoCard 100.015.572 PubChem 15629 ChemSpider 14868 Wikidata Q6901670
properties
Molar mass	214.65 g mol −1
Physical state	firmly
density	1.3 g cm −3
Melting point	81.5 ° C
boiling point	decomposes before boiling at 220 ° C
Vapor pressure	6.4 10 −6  Pa (20 ° C)
solubility	very sparingly soluble in water (580 mg l −1 at 20 ° C, pH 9) easily soluble in acetone (200 g l −1 at 20 ° C)
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution H and P phrases H: 302-373-410 P: 273-301 + 312 + 330-314
Toxicological data	1800 mg kg −1 ( LD 50 ,  rat ,  oral ) 1690 mg kg −1 ( LD 50 ,  Vogel ,  oral )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Monolinuron is a synthetic herbicide from the phenylureas substance class . It was brought onto the market by Hoechst in 1958 .

presentation

4-chloroaniline reacts with phosgene to form isocyanate . This is reacted with N , O -dimethylhydroxylamine , resulting in monolinuron.

properties

Monolinuron is a white, crystalline and odorless solid. In a neutral medium it is stable to hydrolysis, but it degrades quickly in alkaline and acidic areas. It also decomposes when exposed to UV light. In the soil it is moderately persistent with a half-life of 60 days. When liquid formulations are exposed to heat, toxic and explosive gas mixtures can be formed.

Mode of action and use

The mode of action of monolinuron is analogous to other phenylurea herbicides. It inhibits the electron transport of photosystem II . As a result, photosynthesis comes to a standstill and the plant dies.

Monolinuron can be used both as a pre-emergence herbicide and for post-emergence treatment against broad-leaved weeds and annual grasses. It can be used in a wide variety of areas, for example in fruit, vegetable and grain cultivation, but also in ornamental plants and in viticulture.

The active ingredient can also be used as an algicide, for example against thread algae.

toxicology

The active ingredient is classified by the WHO as "unlikely to be toxic". Nevertheless, adequate protection should be provided during use, as hydrogen chloride and nitrogen oxides can be formed.

Admission

In any Member State of the European Union as well as Switzerland are pesticides registered with monolinuron.

Individual evidence

1. ↑ ^{a b c d e f g} Entry on monolinuron in the Pesticide Properties DataBase (PPDB) of the University of Hertfordshire , accessed on July 10, 2020.
2. ↑ ^{a b c d e f} Entry on monolinuron in the GESTIS substance database of the IFA , accessed on July 10, 2020 (JavaScript required)
3. ↑ Entry on monolinuron in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on July 10, 2020. Manufacturers or distributors can expand the harmonized classification and labeling .
4. ↑ Thomas A. Unger: Pesticide synthesis handbook . Noyes Publications, 1996, ISBN 0-8155-1401-8 , pp. 360 ( limited preview in Google Book Search).
5. ↑ ^{a b c} Paranjape, Kalyani .: The pesticide encyclopedia . CABI, Wallingford, Oxfordshire UK 2014, ISBN 978-1-78064-014-3 ( limited preview in Google Book Search).
6. ↑ Entry on monolinuron. In: Römpp Online . Georg Thieme Verlag, accessed on July 10, 2020.
7. ↑ General Directorate Health and Food Safety of the European Commission: Entry on monolinuron in the EU pesticide database ; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on July 10, 2020.