Thiophosphates

Thus the condensation of dichloroether or chloroacetone fails to give the parent compound, 2-hydroxythiazole (158a), Rj = R2 = R3 = H (221). However, 2-hydroxythiazole can be obtained in 12% yield from chloro-acetaldehyde (386). The condensation of ammonium thiocarbamate with cf-chloroketones gives the corresponding 2-hydroxy derivatives in 25 to 70% yields (76, 221, 304, 412) (Table 11-24). These compounds condensed with ClP(S)(OEt)2 give the corresponding 2-thiazolyl-thiophosphates (791). 

The reaction of thioethers with ethyleneimine in the presence of acid yields sulfonium compounds. The reaction is reversible under alkaline conditions (125). Compounds in which double-bonded sulfur can exist in tautomerism with a form having a free SH group, such as thiourea (126,127), thiocarboxyhc acids (128), and thiophosphates (129), react to give aminoaLkylated products. The P-aminoethyl thiocarboxylate rearranges to give the amide. 

The hydrolysis of phosphoms sulfides has been studied quantitatively. A number of products are formed (Table 6). Whereas phosphoms(V) sulfide reacts slowly with cold water, the reaction is more rapid upon heating, producing mainly hydrogen sulfide and orthophosphoric acid, H2PO4. At high pH, P4S Q hydroly2es to a mixture of products containing thiophosphates and sulfides. 

Thiiranes (77) show some juvenile hormone activity, but the epoxide is often more active. Thiophosphates of 2-mercaptomethylthiirane are strong contact insecticides 2-chloromethylthiirane and4-vinyl- 1,2-epithiocyclohexane are nematocides. Severalthiirane 1 -oxides are reported to be insecticides, molluscicides and herbicides (68USP3413306). 1,2-Epithio-1,2,3,4-tetrahydronaphthalene is a mild herbicide. 

Thiirane, 2-keto- — see a-Thiolactones Thiirane, 2-mercaptomethyl-thiophosphate insecticide, 7, 183 tuberculosis inhibition by, 7, 183 Thiirane, 2-methyl-adducts... 

Triisooctyl thiophosphate [30108-39-5] through a column of activated alumina. 

Nucleotide thiophosphate analogues. The preparation and purification of [ H]ATPyS, [ HJGTPyS, s ITPyS (6-thioinosine), cl ITPyS (6-chloroinosine) and [ HJATPyS are described and the general purification... 

Phosphorothioate 0,0-DiethylO-2-Isopropyl-4-Methyl-6-Pyrimidyl Thiophosphate Diethyl 2-Isopropyl-4-Methyl 6-Pyrimidyl Thionophosphate Alpha-Tox Saralex Spectracide Cherrucal Formula C]2H2iNj03PS. 

Chemical Designations - 5[yn >r m5 MPT 0,0-Dimethyl 0-(p-Nitrophenyl) Phosphorothiorate 0,0-Dimethyl 0-p-Nitrophenyl thiophosphate Parathion-methyl Chemical Formula (CH30)2PS0CjH4N02-P-... 

Chemical Designations - Synonyms 0,0-Diethyl 0-(p-nitrophenyl) phoshorothioate 0,0-Diethyl O-(p-nitrophenyl) thiophosphate Ethyl Parathion Phosphoroiioic acid 0,0-diethyl 0-p-nitrophenyl... 

Presumably intermediate thiophosphoric acids are first formed and, indeed, when the hydrolysis is carried out in aqueous NaOH solution at 100°, substantial amounts of the mono- and di-thiophosphates are obtained. P-S bonds are also retained during reaction of P4S10 with alcohols or phenols and the products formed are used extensively in industry for a wide variety of... 

Chemical Name 2-[(diethoxvphosphinvl)thio]-N,N,N-trimethvlethanaminium iodide Common Name 0,0-diethvl-S-/3-dimethvlaminoethvl thiophosphate methyl iodide Structural Formula ... 

C23H3g03Si 152185-73-4) see Docetaxel trisodiuin thiophosphate dodecahydrate (H24Na30isPS 51674-17-0) see Amifostine [S-(/f 4 )]-A,A, a-tris(phenylmethyl)oxiranemcthan-amine... 

Titanium(III) chloride (particularly in slightly alkaline medium) reduces the p-nitro groups of the thiophosphate insecticides to amino groups, which are then reacted with nitrite in acid mediiun in a second step to yield a diazonium compound as intermediate. This is then coupled to N-(l-naphthyl)-ethylenediamine dihydrochloride to yield an azo dye [3]. In the case of benzodiazepines the first reaction step includes an additional acid hydrolysis to the corresponding benzophenone derivative [2]. 

The detection limits for thiophosphate insecticides are 40-100 ng substance per chromatogram zone [1],... 

Fig. 1 chromatogram of the thiophosphate insecticides (each ca. SOO ng) after treatment with dipping solutions I and II (A) before and (B) after complete drying of the TLC plate. TVacks 1 and S mixture Track 2 azinphos ethyl Track 3 malathion Track 4 diazinone. 

The hydrolytic action of alkalis on the thiophosphate insecticides, such as parathion, yields free phenols that then couple with the diazonium salt to yield azo dyes. 

The chromatograms are freed from mobile phase in a stream of warm air for 3 min, then immersed in dipping solution I for 3-5 s or uniformly sprayed with spray solution I. Then, except in the case of thiophosphate insecticides, the plate is immediately immersed in dipping solution II for 3-5 s or homogeneously sprayed with spray solution II. In the case of thiophosphate insecticides there is a delay of 2 min [4] or the plates are heated to 70-110 °C for 10-15 minutes before the plates are erposed to the second reagent solution. 

Note It is occasionally recommended that sodium acetate be added to the reagent [2]. Thiophosphate insecticides with a simple P—S bond yield yellow chromatogram zones and those with a P=S double bond yield brown ones on a light brown background [10]. Further treatment of the stained chromatogram with iodine vapors increases the detection sensitivity [7] more than does spraying afterwards with caustic soda solution, which is also occasionally recommended [16, 17, 20, 21]. 

Demeton-S-methyl sulfone (hRf 0-5), dimethoate (h/ f 5-10), demeton-S-metlq (hRf 20-25), triazophos (h/ f 40-45), azinphos-methyl (hRf 40-45), azinphos-ethj (hRf 50-55), malathion (h/ f 60-65), parathion-methyl (hRf 75-80) and parathioo ethyl (h/ f 80-85) yielded yellow to brown chromatogram zones on a light brown bact ground, with thiophosphate insecticides with P = S double bonds appearing as brow zones and those with single P — S bonds as yellow zones. 

The reaction course has not been elucidated (cf. also sodium hydroxide reagent). Hydrolyzation reactions and aromatizations are probably primarily responsible for the formation of colored and fluorescent derivatives. Substituted nitrophenols - e.g. the thiophosphate insecticides — can probably be hydrolyzed to yellow-colored nitro-phenolate anions by sodium hydroxide or possibly react to yield yellow Meisenheimer complexes. Naphthol derivatives with a tendency to form radicals, e.g. 2-naphthyl benzoate, react with hydrolysis to yield violet-colored mesomerically stabilized 1,2-naph-thalenediol radicals. 

Note Methanolic sodium hydroxide solution can replace potassium hydroxide solution [16] (q.v.). The production of color tones and fluorescence is very dependent on the duration and temperature of heating hence optimal conditions must be determined empirically [16]. Some thiophosphate insecticides do not form fluorescent derivatives [16]. The natural fluorescence of various cumarin derivatives is intensified [1]. 

The detection limits as substance per chromatogram zone are 1 pg for polyacrylonitrile [20] and 2-arylazo-2-nitroethane derivatives [19] and 6-100 ng for thiophosphate pesticides [16]. 

Tetrabromophthalein ethyl ester potassium salt is a pH indicator that changa from blue to yellow in the pH range 4.2-3. It is known that proteins and alkaloids fordli blue-colored salt-like adsorption compounds with this indicator that are not destroyeti by weak acids [3]. Thiophosphate pesticides and triazines possibly form similar conhi pounds. 

---