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CAS 68957-94-8 Peptide/Amide Coupling Reagent Peptide/Amide Coupling Reagent

Propanephosphonic Acid Anhydride 50% Solution (T3P)

IUPAC: 2,4,6-Tripropyl-1,3,5,2?5,4?5,6?5-trioxatriphosphinane-2,4,6-trione View on PubChem
CAS NUMBER
68957-94-8
MOL. FORMULA
C9H21O6P3
MOL. WEIGHT
318.18 g/mol
Scientific Overview

T3P activates carboxylic acids toward nucleophilic attack by amines, forming amide bonds with minimal racemization at stereocenters. Its water-soluble phosphonate by-products simplify aqueous workup compared to classical carbodiimide-based coupling reagents, and it is widely adopted in industrial-scale API amide-coupling processes, including for peptide and small-molecule pharmaceutical synthesis.

T3P (propanephosphonic acid anhydride) is a cyclic trimeric phosphonic anhydride widely used as a low-toxicity, low-epimerization coupling reagent for amide and peptide bond formation, valued for its water-soluble by-products and broad functional-group tolerance.

Full Technical Data
Chemical Name Propanephosphonic Acid Anhydride (T3P; n-Propylphosphonic Anhydride)
CAS Number 68957-94-8
IUPAC Name 2,4,6-Tripropyl-1,3,5,2?5,4?5,6?5-trioxatriphosphinane-2,4,6-trione
Molecular Formula C9H21O6P3
Molecular Weight 318.18 g/mol g/mol
Boiling Point 200°C at 0.3 torr
Density 1.069 g/mL at 25°C
Refractive Index 1.418
Reaction Scheme
n-Propylphosphonic Dichloride
Water
NA
Propanephosphonic Acid Anhydride (T3P)
NA
Commercial Applications

Peptide Bond Coupling

Low-epimerization coupling reagent for solution-phase and solid-phase peptide synthesis.

API Amide Bond Formation

Widely used in industrial process chemistry for amide coupling steps in small-molecule drug synthesis.

Green Chemistry Coupling Reagent

Preferred over classical carbodiimide reagents for its water-soluble, easily removed by-products.

Multi-Purpose Dehydrating Agent

Used in ester synthesis, Weinreb amide formation, and various dehydration/cyclization reactions.

Market Therapeutic Focus
PEPTIDE/AMIDE COUPLING REAGENT PHARMACEUTICAL MANUFACTURING PEPTIDE THERAPEUTICS API PROCESS CHEMISTRY ORGANIC SYNTHESIS INTERMEDIATES CRO/CDMO
Scientific Literature

Propylphosphonic anhydride (T3P): An expedient reagent for organic synthesis

Authors: Waghmare, A.A. et al.

Rev. J. Chem.

Propylphosphonic Anhydride (T3P®) as Coupling Reagent for Solid-Phase Peptide Synthesis

Authors: Al Musaimi, O. et al.

ChemistrySelect

T3P: A Mild, Efficient Reagent for Amide and Peptide Bond Formation

Authors: Wissmann, H.; Kleiner, H.J.

Angew. Chem. Int. Ed.

Peer Queries & FAQs
Why is T3P preferred over carbodiimide coupling reagents like DCC?
T3P's by-products are water-soluble phosphonic acid derivatives easily removed by aqueous workup, avoiding the insoluble urea by-products and allergenic potential associated with carbodiimide reagents.
Is T3P suitable for large-scale API manufacturing?
Yes, its mild reaction conditions, low epimerization, and simplified purification make it well suited to industrial process chemistry.
What functional groups is T3P compatible with?
It tolerates a broad range of functional groups and has been used for esterification, dehydration, Weinreb amide formation, and various cyclization reactions beyond simple amide coupling.
What is the recommended storage condition?
Store in a tightly sealed container under inert atmosphere at 2-8°C, protected from moisture, as T3P reacts readily with water.

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