ChemicalBook CAS DataBase List Phosphorous acid

Phosphorous acid synthesis

3synthesis methods

Product Name:Phosphorous acid
CAS Number:13598-36-2
Molecular formula:H3O3P
Molecular Weight:82

Phosphorus acid can be prepared by the reaction of phosphorus trichloride with water:
PCl₃ + 3H₂O → H₃PO₄ + 3HCl
The reaction is violent. Addition of PCl₃ should be extremely cautious and slow. The addition can be carried out safely in the presence of concentrated HCl. Alternatively, a stream of air containing PCl₃ vapor is passed into icecold water and solid crystals of H₃PO₄ form.
Alternatively, phosphorus acid can be prepared by adding phosphorus trichloride to anhydrous oxalic acid:
PCl₃ + 3(COOH）₂ → H₃PO₃ + 3CO + 3CO₂ + 3HCl
In this reaction, all products except H₃PO₃ escape as gases leaving the liquid acid.
Dissolution of phosphorus sesquioxide in water also forms phosphorus acid. When shaken with ice water, phosphorus acid is the only product .
P₄O₆ + 6H₂O → 4H₃PO₃
However, in hot water part of the phosphorus acid disproportionates to phosphoric acid and phosphorus or phosphine.

7732-18-5
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$13.50/100ML

6303-21-5 Synthesis

6303-21-5
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$35.50/50g

13598-36-2
313 suppliers
$25.00/10g

Yield:13598-36-2 84%

Reaction Conditions:

with Ni-doped silica for 18 h;Reflux;

Steps:

0056] Phosphorous acid: (Table 2, entry 12). After concentration of water, 1.72 g (84%) of clear liquid was obtained. ¹H NMR (400 MHz, CDCl₃) δ 6.72 (d, ¹J_HP=663.2 Hz, 1H); ³¹P NMR (161.97 MHz, CDCl₃) δ 4.37 (d, J_PH=664 Hz).

References:

US2014/303394,2014,A1 Location in patent:Paragraph 0036; 0056

6303-21-5 Synthesis

6303-21-5
295 suppliers
$35.50/50g

13598-36-2
313 suppliers
$25.00/10g

References

13697-89-7
154 suppliers
$9.00/5g

13598-36-2
313 suppliers
$25.00/10g

References

Phosphorous acid Related Search:

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