Diethyl-phosphorothionate

Figure 3. Chemical mechanism for the metabolism of parathion to diethyl phosphorothionate and diethyl phosphate by the Cytochrome P-450-containing monooxygenase system (6)...

DEP = 0,0-Diethyl phosphate DETP = 0,0-Diethyl phosphorothionate ECD = electron capture detector FPD = flame photometric detector GC = gas chromatography GPC = gel permeation chromatography MS = mass spectrometry NPD = nitrogen phosphorus detector... 

OP.v are unstable in aqueous solution and even more so in blood owing to the presence of esterase. After ingestion, OP.v decompose in the human body to yield alkyl phosphates. Typical degradation products are dimethyl phosphate (DMP), dimethyl phosphorothionate (DMTP), dimethyl phosphorodithioate (DMDTP), diethyl phosphate (DEP), diethyl phosphorothionate (DETP) and diethylphosphorodithioate (DEDTP), which are formed by the hydrolysis of the ester bond in the OP molecule. In Figure 9.5 the chemical structures of the respective alkylphosphates are shown. ... 

Diethyl phosphate Diethyl phosphorothionate Diethyl phosphorodithioate... 

Paraoxon is the toxic metabolite produced in animals, whereas diethyl-phosphorothionate is a detoxication product. Microorganisms may, under anaerobic conditions, produce amino-parathion, which has a much lower animal toxicity than parathion. Therefore, parathion by oral administration is less toxic to ruminants than to other mammals. The highly active rumen flora detoxicates parathion by reducing it to amino-parathion. However, parathion deposited on leaves or dust particles can absorb light energy and be isomerized to iso-parathion, which has a high animal toxicity. 

Levine, B. and Murphy, S.D. 1977. Effects of piperonyl butoxide on the metabolism of dimethyl and diethyl phosphorothionate insecticides. Toxicol. Appl. Pharmacol., 40, 393-406. 

The active constituent of this insecticide is stated to be 00 -diethyl 0"-ethylmercaptoethyl phosphorothionate,... 

Parathion (OO -diethyl 0"-p-nitropheny 1 phosphorothionate) is known to isomerize to 08-diethyl O -p-nitrophenyl thiophos-... 

It was shown that systox indeed consisted of 00 diethyl (S-ethylmercaptoethyl phosphorothiolate (VIII) and OO -di-ethyl O -ethylmercaptoethyl phosphorothionate (VII). (Compound (IX) was not present, and in any case it does not seem to have been fully characterized.) It seems that at room temperature (VII) isomerizes to (VIII), the half-life being about 3 years. Furthermore, the P=S compound is much less effective than the P=0 compound as an insecticide. 

Among phosphorus insecticides containing also nitrogen and sulphur we may mention 00 -diethyl-/S-/ -diethylaminoethyl phosphorothiolate (X). It was prepared (i) from diethyl phos-phorochloridate1 and sodium / -diethylaminoethyl mercaptide, (ii) from sodium diethyl phosphite and / -diethylaminoethyl thiocyanate, (iii) by the isomerization of OO -diethyl-O"-/ -diethylaminoethyl phosphorothionate (XI) obtained from / -diethylaminoethoxide and diethyl phosphorochloridothionate. 

Synonyms AI3-27311 BRN 1545756 Brodan Caswell No. 219AA CCRIS 7144 Chloryrifos-ethyl Coroban Detmol U.A. 0,0-Diethyl-0-3,5,6-trichloro-2-pyridyl phosphorothioate Dowco-179 Dursban Dursban F EINECS 220-864-4 ENT 27311 Eradex Grofo Killmaster Lentrek Lorsban NA 2783 QMS 971 Phosphorothionic acid, 0,0-diethyl 0-(3,5,6-trichloro-2-pyridyl) ester Pyrinex Terial UN 2783 XRM 429 XRM 5160. 

At 87 °C and pH 2.5, malathion degraded in water to malathion a-monoacid and malathion P-monoacid. From the extrapolated acid degradation constant at 27 °C, the half-life was calculated to be >4 yr (Wolfe et al., 1977a). Under alkaline conditions (pH 8 and 27 °C), malathion degraded in water to malathion monoacid, diethyl fumarate, ethyl hydrogen fumarate, and QO-dimethyl phosphorodithioic acid. At pH 8, the reported half-lives at 0, 27, and 40 °C are 40 d, 36 h, and 1 h, respectively. However, under acidic conditions, it was reported that malathion degraded into diethyl thiomalate and 0,0-dimethyl phosphorothionic acid (Wolfe et al, 1977a). 

Synonyms AAT AATP AC 3422 ACC 3422 AI3-15108 Alkron Aileron American Cyanamide 3422 Aphamite Aralo B 404 Bay E-605 Bayer E-605 Bladan Bladan F BRN 2059093 C-06604 Caswell No. 637 CCRIS 493 Compound 3422 Corothion Corthion Corthione Danthion DDF 0,0-Diethyl-0-4-nitrophenyl phosphorothioate 0,0-Diethyl 0-p-nitrophenyl phosphorothioate Diethyl-4-nitrophenyl phosphorothionate Diethyl-p-nitrophenyl thionophosphate 0,0-Di-ethyl-0-4-nitrophenyl thionophosphate 0,0-Diethyl-O-p-nitrophenyl thionophosphate Diethyl-p-nitrophenyl thiophosphate 0,0-Diethyl-O-p-nitrophenyl... 

Diethylmethane. see Pentane Diethylmethylmethane. see 3-Methylpentane Diethyl-4-nitrophenyl phosphorothionate. see Parathion 0,0-Diethyl-O-4-nitrophenyl phosphorothioate. see Parathion... 

Phosphorothionic acid, 00-diethyl 0-(3,5,6-trichloro-2-pyridyl) ester, see Chlorpyrifos Phosphostigmine, see Parathion Phosphothion, see Malathion Phosvit, see Dichlorvos Phthalandione, see Phthalic anhydride... 

It Is well known that phosphorothlonate insecticides such as parathlon (, 0-diethyl p-nitrophenyl phosphorothloate) and malathion [0, -dimethyl -(l,2 -dlcarbethoxy)ethyl phosphoro-dithioate] are Intrinsically poor inhibitors of acetylcholinesterase and in vivo activation to the respective anticholinesterases paraoxon and malaoxon is required before animals exposed to the phosphorothionates are intoxicated. Since metabolic activation is essential to the biological activity of these thiono sulfur-containing organophosphorus insecticides, compounds of this type may be considered as propesticides or, more specifically, prolnsectlcldes. 

Diethyl-0-(2-isopropyl-4-methyl-6-pyrimidinyl) phosphorothionate 0,0-diethyl-0-[6-methyl-2-(1 -methylethyl)-4-pyrimidinyl] phosphorothioate others... 

Diethyldithiocarbamic acid, AE9 >AE65 0,0-Diethyl 2-(ethylsulfinyl)-ethyl phosphorothiolate, A052 0,0-Diethyl 2-(ethylthio)ethyl phosphorothionate, A051 Diethyl fumarate, A007... 

Diethyl U-nitrophenyl phosphorothionate, AS13 0,0-Diethyl 0- -nitrophenyI thio-phosphate, AS13... 

In model (laboratory) experiments, the half-life of MCPA was about 3 days, suggesting that particles might have to be airborne for appreciable time periods in order for breakdown to occur. However, atmospheric drift of emulsified parathion (0 0-diethyl G-p-nitrophenyl phosphorothionate) underwent substantial photooxidation, isomerization, and p-nitrophenol formation within a few minutes (Figure 4) (14). 

DIETHYL-0-2-PYRAZINYL PHOSPHOROTHIONATE O O.O-DIETHYL-O-Z-PYTtAZINYL PHOSPHOTHION-ATE 0,0-DIETHYL-0-PYRAZINYLTHI0PH0SPHATE... 

---