Azidotris dimethylamino phosphonium Hexafluorophosphate

CopyriQhl01999 John Wiley Sona Rairteved from WMW.knoval.eom 

George A. Olah, G. K. Surya Prakash, Qi Wang Xing-ya Li 

Form Supplied in crystalline colorless solid not available from commercial sources. 

Preparative Methods Bromine (1 equiv) is added dropwise to Hexamethylphosphorous Triamide (1 equiv) in dry diethyl ether. After the addition is complete. Potassium Hexafluorophosphate (1 equiv), dissolved in H2O is added, and the solid formed is filtered and washed with H2O. After drying under vacuum, the solid is dissolved in acetone and Sodium Azide (1.5 equiv) is added. The mixture is stirred overnight at 25 °C, then the sodium bromide formed and the excess of sodium azide is filtered off and the solvent is removed under vacuum. Purification by crystallization in a mixture of acetone and diethyl ether. 

Handling, Storage, and Precautions is very stable, not hygroscopic, and can be stored indefinitely under vacuum. The related bromine derivative is an exceptionally safe azide, that does not detonate by shock, friction, rapid heating, or even flame. When used in combination with carboxylic acids, the potential carcinogenic Hexamethylphosphoric Triamide is a side-product and the reagent must be handled with caution.  

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PEPTIDES Azidotris(dimethylamino)phosphonium hexafluorophosphate. Benzotriazole-N-hydroxytris(dimethyIamino)phophoniuin hexafluorophosphate. Cyanogen bromide. Dicyclohexylcarbodiimide. Diethyl phophorocyanidate. 2-Ethyl-7-hydroxybenzis-oxazolium tetrafluoroborate. 1-Hydroxybenzotriazole. N-Hydroxy-S-norbornene-cndo-... 

Although azidotris(dimethylamino)phosphonium hexafluo-rophosphate has not been used in solid-phase peptide synthesis, other commercial phosphonium salt derivatives such as Benzotriazol-l-yloxytris(dimethylamino)phosphonium Hexa fluorophosphate (BOP)," benzotriazoI-l-yloxytris(pyrroli-dino)phosphonium hexafluorophosphate (PyBOP), or bromotris(pyrrolidino)phosphonium hexafluorophosphate (PyBroP) are commonly used in that strategy. 

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