Prochloraz

Structural formula
General
Surname	Prochloraz
other names	N -propyl- N - (2- (2,4,6-trichlorophenoxy) ethyl) -1 H -imidazole-1-carboxamide
Molecular formula	C 15 H 16 Cl 3 N 3 O 2
Brief description	colorless odorless solid
External identifiers / databases
CAS number 67747-09-5 EC number 266-994-5 ECHA InfoCard 100.060.885 PubChem 73665 ChemSpider 66316 Wikidata Q1401484
properties
Molar mass	376.665 g mol −1
Physical state	firmly
density	1.413 g cm −3
Melting point	48-51 ° C
boiling point	222 ° C (decomposition)
Vapor pressure	3.5 · 10 −6 Pa (20 ° C)
solubility	practically insoluble in water (55 mg / l at 25 ° C) soluble in chloroform, xylene, diethyl ether and toluene
safety instructions
GHS hazard labeling from  Regulation (EC) No. 1272/2008 (CLP) , expanded if necessary Caution H and P phrases H: 302-410 P: 273-501
Toxicological data	1600 mg kg −1 ( LD 50 ,  rat ,  oral ) 3000 mg kg −1 ( LD 50 ,  rabbit ,  transdermal )
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Prochloraz is a chemical compound belonging to the imidazole group .

Extraction and presentation

Prochloraz can be obtained through a multi-stage reaction. First, 2,4,6-trichlorophenol is alkylated with 1,2-dibromoethane in a Williamson ether synthesis . The subsequent reaction with propylamine yields a secondary amine which is further reacted with phosgene . This acid chloride of a carbamic acid is finally reacted with imidazole to obtain prochloraz.

properties

In its pure form, prochloraz is a colorless and odorless solid; as a technical product, it is a colorless to brown solid. It hydrolyzes slowly at a pH value of 9 and very slowly at pH values ​​between 5 and 7. It is subject to slow photolysis and decomposes from about 220 ° C. It is a weak base and protonates under acidic conditions (pK _s 3.8). Prochloraz forms stable complexes with certain metal ions, such as zinc Zn ²⁺ . The main route of degradation of the compound in rats is via prochloraz urea, 2- (2,4,6-trichlorophenoxy) ethanol , 2,4,6-trichlorophenoxyacetic acid to 2,4,6-trichlorophenol .

use

Prochloraz is used as a fungicide and used alone or in combination with other active ingredients for attack by grain, in seed dressing , for fungal diseases of other crops such as rapeseed, beets, vegetables, rice and coffee, as well as for the protection of citrus fruits during storage and transport . In 1995 about 1316 t of the compound were sold in Germany. It inhibits the ergosterol - biosynthesis , and also is used as manganese salt (CAS Number: 69192-23-0, or 75747-77-2), copper salt (156065-03-1), or zinc salt (137001-93-5) are used. It was first synthesized in 1974, presented by The Boots Company in 1977 and commercially produced from 1980.

regulation

EU

The currently valid EU approval expires on December 31, 2021. At national level it is approved in 25 EU countries. The permitted daily dose is 0.01, the acute reference dose 0.025 and the acceptable user exposure 0.02 milligrams per kilogram of body weight and day.

The active ingredient prochloraz did not receive EU approval in 2008 because the application for approval was withdrawn. On the basis of a new application, approval as a fungicide was finally granted with effect from January 1, 2012.

Numerous pesticides containing this active ingredient are approved in Germany, Austria and Switzerland . In Switzerland, citrus fruits have a relatively high maximum residue level of 10 milligrams of prochloraz per kilogram.

literature

• Conclusion on the peer review of the pesticide risk assessment of the active substance prochloraz . In: EFSA Journal . tape 9 , no. 7 , 2011, doi : 10.2903 / j.efsa.2011.2323 .

Individual evidence

1. ↑ ^{a b c} Joint Meeting on Pesticide Residues (JMPR), Monograph für Prochloraz (1983) , accessed December 9, 2014.
2. ↑ ^{a b c d e f g} FAO: FAO Specifications and Evaluations for Agricultural Pesticides - Prochloraz (PDF; 147 kB)
3. ↑ ^{a b c d} Entry on N-Propyl-N- (2- (2,4,6-trichlorophenoxy) ethyl) -1H-imidazole-1-carboxamide in the GESTIS substance database of the IFA , accessed on February 6, 2017(JavaScript required) .
4. ↑ Entry on N-propyl-N- [2- (2,4,6-trichlorophenoxy) ethyl] -1H-imidazole-1-carboxamide in the Classification and Labeling Inventory of the European Chemicals Agency (ECHA), accessed on August 1, 2016. Manufacturers or distributors can expand the harmonized classification and labeling .
5. ↑ Thomas A. Unger: Pesticide synthesis handbook . 1996, ISBN 978-0-8155-1401-5 , pp. 435 ( limited preview in Google Book search).
6. ↑ ^{a b c} Andreas Höllrigl-Rosta: Investigations on the residue dynamics of the azole fungicide Prochloraz in soils . January 29, 1999 ( tu-braunschweig.de [accessed June 3, 2019]).
7. ^ Bill Carlile: Pesticide Selectivity, Health and the Environment . Cambridge University Press, 2006, ISBN 978-1-139-45756-9 ( limited preview in Google Book Search).
8. ^ Joint Meeting on Pesticide Residues (JMPR), Monograph for Prochloraz (2001) , accessed December 9, 2014.
9. ↑ ^{a b} Directorate-General for Health and Food Safety of the European Commission: Entry on prochloraz in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on March 13, 2016.
10. ↑ Decision of the Commission of December 5, 2008 on the non-inclusion of certain active substances in Annex I of Council Directive 91/414 / EEC and the withdrawal of the authorizations for plant protection products with these active substances (PDF)
11. ↑ ^{a b} Commission implementing regulation (EU) No 1143/2011 of 10 November 2011 approving the active substance prochloraz ... (PDF)
12. ↑ Ordinance of the EDI on the maximum levels for pesticide residues in or on products of plant and animal origin. In: admin.ch . Retrieved February 7, 2020 .