Phosphorus thiotrichloride

The raw stock for the synthesis of practically important organophosphorus compounds is phosphorus trichloride, phosphorus chlorooxide and phosphorus thiotrichloride. 

Phosphorus thiotrichloride PSC13 is produced in industry by direct interaction of sulfure and phosphorus trichloride at a temperature about 180 °C in the presence of A1C13 as a catalyst. 

Phosphorus thiotrichloride is a colourless transparent liquid (the boiling point is 125 °C). It easily dissolves in benzene, carbon tetrachloride and chloroform it is slowly hydrolysed with water. 

Phosphorus thiotrichloride is raw stock for the production of thiophos, mercaptophos and some other organophosphorus compounds. 

Raw stock phosphorus thiotrichloride (the boiling point is 124-125 °C, PCI3 content is not more than 3%) absoluted ethyl alcohol (the alcohol content is at least 99.7%, aldehyde content is not more than 20 mg/1) sodium hydroxide is flaky solid NaOH, type A (NaOH content is at least 95%) liquid caustic (the density is 1.44 g/cm3, NaOH concentration is at least 42%) benzene (the boiling point is 80.1 °C, the density is 0.875-0.88 g/cm3) /7-nitrophenol (the melting point is 114 °C, the density is 1.479 g/cm3 it dissolves badly in water but well in organic solvents in the diy form explodes by shock) hydrochloric acid (the density is 1.19 g/cm3, HCI content is 27.5%) soda Na2C03 (the density is 2.53 g/cm3, it dissolves well in water). 

Preparation of ethyl dichloride. Synthesis reactor 7 (Fig. 106) is continuously fed through dosing pumps with phosphorus thiotrichloride and absoluted ethyl alcohol from batch boxes 2 and 3 accordingly. 

Methyl monochloride is obtained by the interaction of phosphorus thiotrichloride with methyl alcohol. This forms O-methyldichlorothiophosphate (methyl dichloride) according to the reaction ... 

Methyl dichloride is obtained by the interaction of phosphorus thiotri-chloride with methyl alcohol. The process is carried out in an excess of alcohol (2 moles of CH3OH per 1 mole of PSCI3), which serves to absorb released hydrogen chloride. Phosphorus thiotrichloride from batch box 2 and methyl alcohol from batch box 3 are pumped with batching pumps through siphons into reactor 1. The synthesis occurs when the components are fed simultaneously at 0-5 °C. To withdraw the heat and maintain the temperature in reactor 1, the coil and jacket of the reactor are filled with -15 °C salt solution. The products of the reaction, which include dichloride, unreacted... 

Phosphorus Thiotrifluoride or thiophosphoryl fluoride, PSFs, was first prepared by heating a mixture of phosphorus and sulphur with an excess of lead fluoride in a lead tube to 250° C. and leading over the mixture a current of dry nitrogen. The gas was purified by standing for about a day over dry lime. It was also prepared by heating arsenic trifluoride in a sealed tube with phosphorus thiotrichloride —4... 

Phosphorus Thiotrichloride or thiophosphoryl chloride, PSC13, has been prepared by many reactions —... 

---