Description
Aminocarb is an obsolete insecticide. It is moderalely soluble in water, has a low volatility and tends to be non-persistent in soil and aquatic ecosystems. Based on its chemical properties it is not expected to leach to groundwater. It is highly toxic to mammals and many animal species including pollinators.
Chemical Properties
Tan; crystalline; slightly water-soluble; melting point 93–94C.
Uses
Aminocarb is a carbamate insecticide.
Uses
Nonsystemic, broad-spectrum insecticide used to control the spruce budworm in
forests; molluscicide
Definition
ChEBI: A carbamate ester that is phenyl methylcarbamate substituted by a dimethylamino group at position 4 and a methyl group at position 3.
Production Methods
Aminocarb is commercially produced via a concise 2-step synthesis that begins with nitration of m-cresol to 4-nitro-3-methylphenol using dilute nitric / acetic acid, followed by catalytic hydrogenation to yield 4-amino-3-methylphenol. The key carbamoylation occurs by reacting the aminophenol with methyl isocyanate in toluene in the presence of a catalytic tin compound, forming the methylcarbamate linkage. Final purification via crystallisation from isopropanol or vacuum distillation yields aminocarb.
Mechanism of action
Non-systemic, acetylcholinesterase (AChE) inhibitor.
Environmental Fate
Plant/Surface Water. Several transformation products reported by Day (1991) include
4-amino-m-tolyl-N-methylcarbamate (AA), 4-amino-3-methylphenol (AC), 4-formamidom-tolyl-N-methylcarbamate (FA), N-(4-hydroxy-2-methylphenyl)-N-methylformamide
(FC), 4-methylformamido-m-tolyl-N-methylcarbamate (MFA), 4-methylamino-m-tolyl-Nmethylcarbamate (MAA), 3-methyl-4-(methylamino)phenyl-N-methylcarbamate (MAC),
phenol, methylamine and carbon dioxide. MAA was not detected in natural water but was
detected in fish tissues following exposure to aminocarb-treated water in the laboratory.
The metabolites FA, AC and MAC were detected in Canadian forests treated with aminocarb but the metabolites AA, MAA and FC were not detected (Day, 1991)
On and/or in bean plants, aminocarb degrades with the carbamate moiety remaining
intact. Methylcarbamate derivatives identified include the 4-methylamino, 4-amino, 4-
methylformamido and 4-formamido analogs (Abdel-Wahab et al., 1966)
Photolytic. When aminocarb in ethanol was irradiated by UV light, extensive degradation was observed. No degradation products were identified; however, two unidentified
cholinesterase inhibitors were reported (Crosby et al., 1965).
Chemical/Physical. Aminocarb is hydrolyzed in purified water to 4-(dimethylamino)-
3-methylphenol which is then converted to 2-methyl-1,4-benzoquinone. This compound
was then oxidized to form the following compounds: 6-(dimethylamino)-2-methyl-1,4-
benzoquinone, 6-(methylamino)-2-methyl-1,4-benzoquinone, 5-(dimethylamino)-2-
methyl-1,4-benzoquinone and 5-(methylamino)-2-methyl-1,4-benzoquinone (Leger and
Mallet, 1988). When aminocarb was irradiated by a high pressure xenon-mercury lamp
(λ = 253.7 nm) in aerated and degassed ethyl alcohol and cyclohexene solutions, 4-
dimethylamino-3-methyl phenol formed as the major product. A duplicate run using an
excitation wavelength of >300 nm yielded that same phenol as the major product. Sinceaminocarb absorbs radiation in the solar region (at λ >300 nm), this compound would be
expected to undergo photochemical degradation in the environment (Addison et al., 1974)
Emits toxic fumes of nitrogen oxides when heated to decomposition (Sax and Lewis,
1987)
Metabolic pathway
Aminocarb in purified water is hydrolyzed to 4-
(dimethylamino)-3-methylphenol which is in turn
converted to 2-methyl-1,4-benzoquinone either by
direct means or via 2-methyl-1,4-dihydroquinone. The
benzoquinone reacts readily with methylamine and
diethylamine present in solution to give four red
chemicals. In addition, mono- and diepoxides of
2-methyl-1,4-benzoquinone are formed.
Pesticide Type
Insecticide
