polyphosphoric acid การใช้

• Polyphosphoric acids are used in organic synthesis for cyclizations and acylations.
• Polyphosphoric acid molecules can have dozens of such phosphoric units bonded in a row.
• The situation with higher order polyphosphoric acids and polyphosphates continues in a similar way.
• Other acids, such as sulfuric acid or polyphosphoric acid, can also be used.
• The use of polyphosphoric acid will give acridine products at a lower temperature, but also with decreased yields.
• Alternative route of synthesis : 4-thiazolecarboxamide with " o "-phenylenediamine in polyphosphoric acid.
• Br鴑sted acids such as HCl, H 2 SO 4, polyphosphoric acid and p-toluenesulfonic acid have been used successfully.
• Bronsted acids such as HCl, H 2 SO 4, polyphosphoric acid and p-toluenesulfonic acid have been used successfully.
• Because of the high percentage of phosphoric acid in this reagent, at least some of the orthophosphoric acid is condensed into polyphosphoric acids.
• The Bischler Napieralski reaction is carried out in refluxing acidic conditions and requires a Tf 2 O and polyphosphoric acid ( PPA ) have been used with phenethylcarbamates.
• Conversely, polyphosphoric acids or polyphosphates are often formed by dehydrating a phosphoric acid solution; in other words, removing water from it often by heating and evaporating the water off.
• "' Triphosphoric acid "'( also "'tripolyphosphoric acid "'), with formula H 5 P 3 O 10, is a phosphoric acids, it is the next polyphosphoric acid after pyrophosphoric acid, H 4 P 2 O 7, also called diphosphoric acid.
• The initial phosphoric acid solution may contain 23 33 % P 2 O 5 ( 32 46 % H 3 PO 4 ), but can be concentrated by the evaporation of water to produce " commercial-" or " merchant-grade " phosphoric acid, which contains about 54 62 % pyrophosphoric and polyphosphoric acids will start to form, making the liquid highly viscous ).