Hydramethylnon

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.

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.

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.

Hydramethylon is an insecticide primarily used in the form of baits for cockroaches and ants.

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.

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.

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

Hydramethylnon appears as odorless yellow crystals. Insoluble in water. Used as an insecticide.

Insoluble in water. Hydrolysis occurs rapidly at low and high pHs.

Hydramethylnon is a trifluoromethyl amidinohydrazone.

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.

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.

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 (DT₅₀ 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 (DT₅₀ 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 (DT₅₀ 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 (DT₅₀ 24-30 hours). Products of degradation were not determined (Vander Meer et al., 1982).

Hydramethylnon is a metabolic inhibitor. It works by inhibiting complex III in the mitochondrial inner membrane and leads to a halting of oxidative phosphorylation.