Description
Hydramethylnon is an organic pesticide active ingredient from the trifluoromethyl aminohydrazone chemical class. It is a registered chemical alternative for chlorpyrifos for use as a termiticide and against ants, crickets, and cockroaches around the home and lawn. Hydramethylnon is also used in a wide variety of professional pesticide products and in various formulations, These include foaming products, granular products, gel baits, liquid concentrates.
Chemical Properties
Yellow to orange crystal, solubility (25°C): water 0.005～0.007mg/L, (20°C) acetone 360g/L, chlorobenzene 390g/L, 1,2-dichloroethane 170g/L, ethanol 72g/L, methanol 230g/L, isopropanol 12g/L, xylene 94g/L. Stable at 25°C for 2 years, stable at 45°C for 90 days, decomposition by sunlight DT50 about 1 hour; fluorantrazone aqueous suspension is stable to hydrolysis, DT50 24-33 days (pH 4.9), 10-11 days (pH 7,03), 11-12 days (pH 8.87). Decomposition of DT50 in soil took about 6 days.
History
Hydramethylnon was developed by DuPont in 1975 and introduced to ornamentals industry in the 1990s. Acequinocyl was also discovered by DuPont in the 1970s and further developed by AgroKanesbo Co. Ltd. and Tomen Agro in Japan. Arysta LifeScience first introduced acequinocyl to the U.S. ornamentals market in 2005. Bifenazate was first developed by Uniroyal Chemical in 1990 and commercialized by Crompton Corporation in 1999. Bifenazate was introduced to the ornamental market in 2010.
Uses
Hydramethylon is an insecticide primarily used in the form of baits for cockroaches and ants.
Application
Hydramethylnon is used in baits for selective control of agricultural and household Formicidae (especially Camponot us, Iridomyrmex, Monomorium, Solenopsis and Pogomyrmex spp. and Pheidole megacephala). It is also used to control Blattellidae (especially Blatta, Blattella, Periplaneta and Supella spp.). It can be carried into the nest by worker ants and kill the queen because it is slow acting.
Definition
ChEBI: Hydramethylnon is a member of the class of hydrazones that is used as an insecticide for control of ants and cockroaches. It has a role as a mitochondrial cytochrome-bc1 complex inhibitor and an insecticide. It is a hydrazone, a member of pyrimidines, a member of (trifluoromethyl)benzenes, an olefinic compound and a member of guanidines.
Preparation
Hydramethylnon synthesis was achieved through the coupling in alcoholic media refluxing the compound 1,5-bis[p-(trifluoromethoxy)phenyl]-1,4-pentadien-3-one afforded the desired product in 50% yield.
Synthesis of hydramethylnon
General Description
Hydramethylnon appears as odorless yellow crystals. Insoluble in water. Used as an insecticide.
Air & Water Reactions
Insoluble in water. Hydrolysis occurs rapidly at low and high pHs.
Reactivity Profile
Hydramethylnon is a trifluoromethyl amidinohydrazone.
Safety Profile
Hydramethylnon is safe to use when applied according to label directions. It has been classified by the EPA as being a low threat when it comes to toxicity to humans, pets and birds.
Metabolic pathway
Amdro (AC 217,300) is rapidly photodegraded under
borosilicate-filtered xenon arc lamps at 27 C as a
suspension in distilled water. The half-life of amdro is
calculated as 42 min and four degradation products
are identified as 1,5-bis(a,a,a-trifluoro-p-tolyl)-1,4-
pentadien-3-one, a,a,a-trifluoro-p-toluic acid, p-
(trifluoromethyl)cinnamic acid, 6,7,8,9-tetrahydro-7,7-
dimethyl-3-[p-(trifluoromethyl)styryl]-4H-pyrimido[2,1-c]-
as-triazin-4-one. These degradation products are
identical to those of the metabolites by insect.
Degradation
Hydramethylnon is relatively involatile and has a very low water solubility
for a compound of intermediate lipophilicity. Such a low water
solubility may have consequences for the redistribution in the environment
and the toxicological properties of the insecticide. Hydramethylnon
is rapidly degraded in sunlight by photolysis (DT
50 about 1 hour) (PM).
Mallipudi et al. (1986) studied the photolytic degradation of a suspension
of hydramethylnon in distilled water. Stirred suspensions of [
14C-benzylic]-
or [2-
14C-pyrimidinyl]-hydramethylnwone re exposed to a xenon lamp
(filtered to simulate natural sunlight) at 27°C for 60 or 90 minutes.
Experiments were done using 1:l mixtures of
14C- and
13C-radiolabelled
compounds to aid identification of photoproducts by CI, PI, and NI
GC-MS with a pulsed positive-ion negative-ion chemical ionisation
accessory. Analysis was also done using a range of TLC and HPLC
methods. [
14C-benzylic]- and [2-
14C-pyrimidinyl]-Hydramethylnon.photo-degraded
very rapidly (DT
50 41.9 minutes). HPLC analysis showed 16
metabolites from benzylic-labelled and 9 from pyrimidine-labelled
material. Identified photoproducts of [
14C-benzylic]hydramethylnowne re
the pentadienone (2), the benzoic acid (3) and the cinnamic acid (4). In
addition, the cyclic derivative (5) was characterised as a photoproduct
of both [1 4C-benzyEic]- and [2-
14C-pyrimidinyl]-hydramethylnon.Control
samples were maintained in the dark for comparison. The photoproducts
were of minor importance because they were less abundant than the
parent hydramethylnon at all sampling times (HSE, 1994).
Unlabelled hydramethylnon was prepared (presumably as a suspension)
in aqueous buffer solutions of pH 4.8,6.5 and 8.0. The suspensions
were exposed to sunlight (December, West Bengal, India, average temperatures
in the range l0
-25 °C) for 10 hours. Solutions of different pH
degraded at similar rates (DT
50 3.5 hours). In a study done for comparison
no significant degradation of hydramethylnon occurred in the dark. In an
additional study done to identify photoproducts, a concentrated suspension
of hydramethylnon was suspended in aqueous buffer (pH 6.5) and
exposed to natural sunlight for 20 hours. The solution was analysed using TLC, GC and column chromatography. The pentadienone (2) was formed
by hydrolytic cleavage of hydramethylnon. The resulting hydrazine
cleavage product probably underwent self condensation to form the
1,stetrazadiene (6). The condensation may have resulted from the high
concentrations used in the study (Chakraborty et al., 1993). A commercial
bait formulation of hydramethylnon was spread in trays and placed outdoors
(in Florida in June) for up to 4 days. At intervals, samples were
taken and analysed by GC. Hydramethylnon was only degraded during
daylight hours (DT
50 24-30 hours). Products of degradation were not
determined (Vander Meer et al., 1982).
Mode of action
Hydramethylnon is a metabolic inhibitor. It works by inhibiting complex III in the mitochondrial inner membrane and leads to a halting of oxidative phosphorylation.
