Propanephosphonic acid anhydride

Propanephosphonic acid anhydride (PPAA, T3P) is an anhydride of propanephosphonic acid. Its structure is a cyclic trimer, with a phosphorus–oxygen core and propyl groups and additional oxygens attached.^[1] The chemical is a useful reagent for peptide synthesis reactions, where it activates the carboxylic acid partner for subsequent reaction with amines. It is commercially available as 50 % solution in DMF or ethyl acetate as a slightly yellow mixture.

Propanephosphonic acid anhydride

Names
Preferred IUPAC name 2,4,6-Tripropyl-1,3,5,2λ5,4λ5,6λ5-trioxatriphosphinane-2,4,6-trione
Other names PPACA; PPAA; T3P; Propylphosphonic anhydride
Identifiers
CAS Number	68957-94-8
3D model (JSmol)	Interactive image
ChemSpider	100355
ECHA InfoCard	100.102.078
EC Number	422-210-5
PubChem CID	111923
UNII	I6EGD8839N
CompTox Dashboard (EPA)	DTXSID20219011
InChI InChI=1S/C9H21O6P3/c1-4-7-16(10)13-17(11,8-5-2)15-18(12,14-16)9-6-3/h4-9H2,1-3H3 Key: PAQZWJGSJMLPMG-UHFFFAOYSA-N
SMILES CCCP1(=O)OP(=O)(OP(=O)(O1)CCC)CCC
Properties
Chemical formula	C9H21O6P3
Molar mass	318.182 g·mol−1
Hazards
GHS labelling:
Pictograms
Signal word	Warning
Hazard statements	H290, H314
Precautionary statements	P234, P260, P264, P280, P301+P330+P331, P303+P361+P353, P304+P340, P305+P351+P338, P310, P321, P363, P390, P404, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references