ДИФЕНИЛФОСФИНОВЫЙ АНГИДРИД

Description

Diphenylphosphinic anhydride is a symmetrical diphenylphosphinic anhydride in which two Ph2P(O) units are linked through a bridging oxygen atom. English name Diphenylphosphinic anhydride, formula C24H20O3P2, CAS 5849-36-5. It is related to diphenylphosphinic acid and diphenylphosphinic chloride and belongs to the same class of reagents in organophosphorus synthesis.

Basic Attributes

• CAS No: 5849-36-5
• Chemical formula: C24H20O3P2
• Molecular weight: 418.36
• Exact weight: 418.08900
• DSSTox ID: DTXSID70346523
• PSA specifications: 43.4
• XLogP3: 4.86120

Physico-chemical characteristics

• Density: 1.28 g/cm3
• Melting point: 146 °C
• Boiling point: 555.3 °C at 760 mmHg. Art.
• Flash point: 302.5 °C
• Refractive index: 1.629

Scope of application

Diphenylphosphinic anhydride, like its related diphenylphosphinic acid, is used in the synthesis of bidentate phosphine ligands and peptide condensing agents. The anhydride form is reactive towards nucleophiles - alcohols and amines - and is used as a convenient phosphorylating reagent for the preparation of phosphinate esters and phosphinamides without the release of corrosive hydrogen chloride, which is characteristic of working with the acid chloride of the same acid.

Toxicity and danger

Hazard Statement: H315 - Causes skin irritation (100% GHS). Hazard class code: 36/37/38 (irritating to eyes, respiratory tract and skin).

Safety Information

Safety instructions: 26-36/37/39. Precautions: P264, P280, P302+P352, P305+P351+P338, P321, P332+P313, P337+P313, P362.

Storage and transportation conditions

Store in an airtight container in a cool, dry place - the anhydride bond is hydrolytically sensitive to moisture. Wear gloves and safety glasses, avoid dust.

Comparison with acid chloride

In terms of reactivity, the anhydride is inferior to the corresponding phosphinic acid chloride, but benefits in ease of handling: the reaction with the nucleophile is not accompanied by the release of corrosive hydrogen chloride, which simplifies the selection of reactor materials and reduces the requirements for neutralization of waste gases. This reactivity profile is especially valuable when working with acid-sensitive substrates where the presence of traces of HCl is undesirable.

Features of production and purification

The anhydride is obtained by dehydration of diphenylphosphinic acid or partial hydrolysis of the corresponding acid chloride, followed by separation from the by-product acid and residual water by recrystallization; Controlling the free acid content of the commercial product is important because its presence can distort the stoichiometry of the subsequent phosphorylation reaction and reduce the yield of the target product in sensitive synthetic protocols.

Symmetrical structure and its meaning

The symmetrical structure of the molecule - two identical phosphinyl fragments connected through a common oxygen atom - means that when reacting with a nucleophile, the target phosphorylation product and a second molecule of diphenylphosphinic acid are released as a by-product; this stoichiometric ratio is taken into account when calculating the reagent load and assessing the economics of the process, especially in large-scale production conditions, where even small losses of raw materials significantly affect the cost.

Place in the laboratory arsenal

Compared to more widely known phosphorylating reagents, phosphinic anhydride remains a niche but indispensable tool where compatibility with acid-sensitive protecting groups of the substrate is critical - a typical situation in the multi-step synthesis of natural compounds and complex pharmaceutical intermediates.