Synthesis of sodium monothiophosphate

Preparation of sodium monothiophosphate dodecahydrate

Preparation of sodium monothiophosphate dodecahydrate

Preparation of sodium monothiophosphate dodecahydrate

A one liter three-neck flask is fitted with a dropping funnel, a thermometer, and a mechanical stirrer. 120 g of sodium hydroxide (calculated as the 100% salt) and 400ml of water are placed in the flask and 70g of phosphorus (V) sulfochloride are added to the well-stirred alkali. The mixture is heated under stirred reflux until the layer of sulfochloride has disappeared; this requires about 30 minutes. The reaction mixture is gradually cooled in an ice bath and 100ml of alcohol are slowly added through the dropping funnel. When the contents of the flask have cooled to 5°C or below, the cold slurry is filtered, and the crude product, contaminated with sodium chloride, is filtered off and drained well. Yield about 125g. The solid obtained here is dissolved in 90ml of water below 50 °C and the solution is cooled rapidly in ice to 0°C. An analytically-pure material is obtained by filtering and draining the solid without washing.

Inorganic laboratory preparations, by G. G. Schlessinger, 62-63, 1962

In order to prepare anhydrous sodium monothiophosphate 40g of 100% sodium hydroxide in 300ml of water and 17.5ml of phosphorus (V) sulfochloride are heated at 103-109 °C for 15-20 minutes, the reaction is complete. The crude material is redissolved in the minimum of water at 40-45°C and the crystalline product is precipitated by the addition of 185ml of anhydrous methanol for every 100ml of solution. The sodium monothiophosphate 12-hydrate is filtered off after cooling and the procedure of precipitating crystals is repeated. The isolated salt is then dehydrated by stirring it for one hour with 200ml of anhydrous methanol. After filtering, the material is dried at 100°C for one hour and stored in a well-sealed vessel. The anhydrous compound decomposes at 120-125°C. Yield 16-17g.

Inorganic laboratory preparations, by G. G. Schlessinger, 63, 1962

Preparation of sodium monothiophosphate dodecahydrate_

Preparation of sodium monothiophosphate dodecahydrate_

50 g of sodium hydroxide are dissolved in 250ml of water and 50g of phosphorus(V) sulfide are added in portions at such a rate that the temperature remains below 50°C. This is accomplished by cooling with water. The yellow solution is cooled in ice and 100ml of alcohol are added. After remaining in the cold for 2-3 hours, the precipitated salt is filtered and washed with 75ml of cold 50% alcohol, then with the same volume of pure alcohol, and finally dried in air. This salt is dissolved in 350ml of water and warmed to 70°C on the steam bath until a vigorous evolution of hydrogen sulfide starts. The solution is immediately cooled to 60° and held at this temperature for 10-15 minutes. After rapid cooling in ice, 100ml of alcohol are added and the product is isolated by filtering without washing. The material is recrystallized by dissolving it in the minimum of water at 45°C, cooling, and then precipitating the sodium monothiophosphate 12-hydrate by adding one-fifth the volume of alcohol.

Inorganic laboratory preparations, by G. G. Schlessinger, 63-64, 1962





InChI Key


Canonical SMILES


MeSH Synonyms

diethyl thiophosphate, sodium thiophosphate, thiophosphate, thiophosphoric acid, thiophosphoric acid, trisodium salt

Depositor-Supplied Synonyms

Sodium phosphorothioate, Trisodium thiophosphate, Trisodium monothiophosphate, Thiophosphoric acid, trisodium salt, EINECS 233-261-6, Phosphorothioic acid, trisodium salt, AC1OC7DY, sodium; trihydroxy(sulfanylidene)-, 13598-51-1 (Parent), IN005899, Phosphorothioic acid, sodium salt (1:3), LS-108970

Removed Synonyms

Sodium thiophosphate, Trisodium phosphorothioate, TRISODIUM THIOPHOSPHATE HYDRATE, CID6913045, 10101-88-9

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