A Simple Straightforward Synthesis of Phenylphosphane and the Photoinitiator Bis(mesitoyl)phenylphosphane Oxide (IRGACURE 819)

Authors

  • Hansjörg Grützmacher
  • Peter Murer
  • Jean-Pierre Wolf
  • Souad Boulmaaz
  • Reinhard H. Sommerlade
  • Hartmut Schönberg
  • Timo Ott
  • Daniel Stein
  • Jens Geier
  • Thomas Ulrich

DOI:

https://doi.org/10.2533/chimia.2008.18

Keywords:

Acylphosphanes, Ion triples, Phosphanes, Phosphorus, Photoinitiators, Sodium

Abstract

A straightforward high-yield synthesis for the photoinitiator bis(2,4,6-trimethylbenzoyl)phenylphosphane oxide (16, IRGACURE 819) involves: i) the reaction of phenyldichlorophosphane, PhPCl2, with sodium to give [Na2(P2Ph2)(tmeda)]6 (5); ii) protonation of 5 with tert-butanol to give 1,2-diphenyldiphosphane, PhHP-PHPh (12); iii) reduction of 12 by sodium to yield [Na(PHPh)]x (13); iv) protonation of 13 with tert-butanol to give phenylphosphane PhPH2 (14) in excellent yields; v) reaction of 14 with 2,4,6-trimethylbenzoylchloride (MesCOCl) in presence of the NaOt-Bu formed in steps ii and iv to give bis(2,4,6-trimethylbenzoyl)phenylphosphane 7; vi) oxygenation of 7 with 30% aqueous hydrogen peroxide to give the final product 16. This reaction can be performed in toluene with about 4 vol-% of tmeda as an activator in a one-pot synthesis without changing the solvent. The structures determined by X-ray diffraction of the unique hexameric aggregate 5 and 16 are reported.

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Published

2008-02-27

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Section

Scientific Articles