PyAOP reagent

PyAOP ((7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate) is a reagent used to prepare amides from carboxylic acids and amines in the context of peptide synthesis.^[1] It can be prepared from 1-hydroxy-7-azabenzotriazole (HOAt) and a chlorophosphonium reagent under basic conditions.^[2] It is a derivative of the HOAt family of amide bond forming reagents. It is preferred over HATU, because it does not engage in side reactions with the N-terminus of the peptide.^[3] Compared to the HOBt-containing analog PyBOP, PyAOP is more reactive due to the additional nitrogen in the fused pyridine ring of the HOAt moiety.^[4] Thermal hazard analysis by differential scanning calorimetry (DSC) shows PyAOP is potentially explosive.^[5]

PyAOP reagent

Names
IUPAC name (7-Azabenzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate
Other names PyAOP
Identifiers
CAS Number	156311-83-0
3D model (JSmol)	Interactive image
ChemSpider	9213814 Y
ECHA InfoCard	100.155.575
PubChem CID	11038641
UNII	C5Z532MU8E Y
CompTox Dashboard (EPA)	DTXSID00935424
InChI InChI=1S/C17H27N7OP.F6P/c1-2-11-21(10-1)26(22-12-3-4-13-22,23-14-5-6-15-23)25-24-17-16(19-20-24)8-7-9-18-17;1-7(2,3,4,5)6/h7-9H,1-6,10-15H2;/q+1;-1 Key: CBZAHNDHLWAZQC-UHFFFAOYSA-N
SMILES C1CCN(C1)[P+](N2CCCC2)(N3CCCC3)ON4C5=C(C=CC=N5)N=N4.F[P-](F)(F)(F)(F)F
Properties
Chemical formula	C17H27F6N7OP2
Molar mass	521.389 g·mol−1
Appearance	White crystals
Melting point	163–168 °C (325–334 °F; 436–441 K)
Hazards
Occupational safety and health (OHS/OSH):
Main hazards	Irritant
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

See also

• HOAt reagent
• HOBt reagent
• BOP reagent
• PyBOP