CS245541B1 - Method of triphenylphosphanoxide preparation - Google Patents

Abstract

The present invention relates to a process for preparing triphenylphosphane oxide of formula Ph 3 PO where Ph is phenyl. The nature of the process is that triphenylphosphane is oxidized with oxygen to triphenylphosphine oxide in acetonitrile at 290 to 200 ° C 350 K for bis (triiodide) catalytic effect ferrous tetra (triphenylphosphane oxide) of formula Fe (Ph 3 PO) 4 (13) 2, wherein Ph is phenyl. The triphenylphosphine oxide obtained can be found as a complexing agent metal extraction (for example, Cr, Zn, Fe, Co, Cu, Zn, U), in the production of plasticizers, fireproof additives and biologically active substances.

Description

The invention relates to a process for the preparation of triphenylphosphane oxide by oxidation of triphenylphosphane with oxygen.

Triphenylphosphane is a relatively stable oxidation compound and stronger oxidants are required to oxidize it. For example, triphenylphosphine oxide PhsPO can be prepared by oxidizing triphenylphosphane with bromine Brz in an aqueous medium (Handbuch der Praparativen Chemie, Stuttgard 1937). The disadvantages of this oxidation method are the non-selectivity of the reaction and the strong corrosive effect of bromine on the apparatus. The selective oxidation of triphenylphosphane is achieved primarily by using some transition element complexes (e.g. Pd, Pt, Ru, Zr, Ni, Mo, Co) as catalysts. Catalytic oxidation of PhsP with oxygen also occurs in the presence of iron complexes. The complexes of [(CaH5) Nj2, [Fe (mnt) 3] and [(C2H5) 4N), [Fe (mnt) 2] (mnt = cis-1,2-dicyanoethylene-1,2-dithiolite) act as catalysts in acetonitrile solution (T = 298 K), whereby 15 moles of PI13P and [Fe (mnt) 2] ^- 10 moles of Ph3P are oxidized with 1 mole of [Fe (mnt) s] ^2- catalyst (J. Amer. Chem. Soc. 95, 4). 847, 1973). In the presence of TPPFe (II) porphyrin complex (TPP = inter-tetrafenyl-porphyrin anion), oxidation takes place in a toluene solution at T = 298 K. In the presence of 1 mole of TPPFe (II) at least 27 moles of PhsP are oxidized (J. Amer. Chem. Soc., 102, 5,945 (1980). More efficient catalysts are iron (III) triphenylphosphine oxide complexes of FeX3 (Ph3) 2 type, where X is Cl, Br, NCS, as well as FeXs type compounds, wherein X is Cl, Br, NCS and I in acetonitrile solution at a slightly elevated Cs. AO č. 205 483). A disadvantage of the above mentioned catalytic oxidations is the use of less efficient catalysts than the newly prepared compound Fe (Ph3PO) 4 (13) 2. For example, using Fe (Ph 3 P) s (L 3) 2 as catalyst in a concentration of n _s = 3,8.10 ^-3 mol ^dm-3 at 338 K can be zoxidovaf 1 mol of the catalyst to 270 mol PI13P while e.g. in the presence of 1 mole of catalyst Fe (NCS) 3 (Ph 3 PO) 2100 moles PhsP. Its high catalytic activity is also indicated by the fact that the oxidation of PhsP catalyzed by Fe (Ph 3 PO) 4 (13) 2 lasted 50 hours while in the presence of Fe (NCS) 3 (Ph 3 PO) 2 it lasted 100 hours.

The above drawbacks are eliminated by the preparation of triphenylphosphane oxide by reacting triphenylphosphane with oxygen according to the invention, which consists in the oxidation of triphenylphosphane under the catalytic action of the Fe (Fe13ΡΟ) 4 (I3) 2 complex, where Ph is phenyl, in acetonitrile at T = 290 to 350 K. The higher effect of the process of the invention is the use of a much more efficient Fe (Ph 3 PO) 4 (13) 2 catalyst, which results in shorter reaction times, lower catalyst concentrations and more catalytic cycles.

The invention is described in the following examples.

Example 1

Oxygen purged reaction vessel (T = 323 K) was charged with 1.9 x 10 ^-4 moles of Fe (Ph 3 PO) 3 (13) 2, tri-tri-iodide) ferrous tetra (triphenylphosphenoxide), 2. ΙΟ ^'3 moles PHSP, triphenylphosphine, and the connection to the apparatus for measuring the consumption of oxygen at the design ambient pressure was charged with 10 cm ³ of acetonitrile. By monitoring the dependence of O2 consumption over time, it was found that the oxidation of triphenylphosphane to triphenylphosphane oxide took 80 minutes, with 95% conversion being achieved after 55 minutes.

Example 1 and d 2

Example 1 was repeated except that the reaction flask contained a larger amount of triphenylphosphane, i.e., 1.9-10 ^-4 moles Fe (Ph 3 PO) 4 (13) 2, 5.10 ^-3 moles PhsP and 10 cm ³ acetonitrile. Measurement of · O2 consumption from time to time revealed that oxidation of triphenylphosphane took 5.5 hours, with 95% conversion being achieved after 200 minutes.

Example 3

Example 1 was repeated with 12.5 times the amount of triphenylphosphane, i.e. the reaction flask contained 2.5 x 10 ^-2 moles of triphenylphosphane, PhsP, 1.9 x 10 ^-4 moles of Fe (Ph 3 PO) 4 (13) 2 complex and 10 cm ^{3 of} acetonitrile. By measuring oxygen uptake from time to time, it was found that the oxidation of PhsP was 45 hours, with 80% conversion being achieved in 30 hours.

Example 4

The whole experiment was carried out in a temperature-controlled reaction vessel (T = 338 K) purged with oxygen containing 5,1.10 ^-3 mmol of triphenylphosphane, 1,9.10 ^_5 mole of Fe (Ph 3 P) 4 (L 3) 2 as catalyst and 5 cm ³ of acetonitrile. Measurement of oxygen consumption and electron spectra revealed oxidation to take 4.5 days, with 95% conversion being achieved in 3.5 days.

Example 5

Example 1 was repeated at a lower temperature (T = 298.5 K) with a larger amount of (Fe (Ph 3 PO) 4 (13) 2 (5.10 ^-4 mol) complex, leaving the amount of triphenylphosphane and acetonitrile unchanged (2.10 ^-3 mol). 10 cm ³ ), and by measuring O2 consumption, it was found that oxidation lasted 7 hours, 95% conversion was achieved in

5,5_ hours.

Pure triphenylphosphine oxide was recovered from the reaction mixture by precipitation with water with the addition of activated carbon.

The purity of PhsPO was controlled by melting point (T m = 429 K), elemental analysis and infrared spectrum in mole (J. Chem. Sov. 1960, 2199).

Analysis results for C 18 H 18 PO (M = 278.29) calculated:

% C, 77.68;% H, 5.43;

% C, 77.84;% H, 5.30.

The yield was 85%.

Claims (1)

SUBJECT The process for the preparation of triphenylphosphine oxide by reacting triphenylphosphane with oxygen is characterized in that the oxidation of triphenylphosphane is carried out at temperatures of 290 to 350 K under the catalytic effect of ferric bis (triiodide) tetra (triphenylphosphine oxide) of formula Fe (Ph3PO) 4 (13) 2. , in acetonitrile.