CS245541B1 - Process for preparing triphenylphosphane oxide - Google Patents

Abstract

The solution relates to a method for preparing triphenylphosphane oxide of the formula Ph3PO, where Ph denotes phenyl. The essence of the method lies in the fact that triphenylphosphane is oxidized with oxygen to triphenylphosphane oxide in acetonitrile at temperatures of 290 to 350 K under the catalytic effect of bis(triiodide tetra (triphenylphosphane oxide) of the iron (II) formula Fe(Ph3PO)4(l3)2, where Ph denotes phenyl. The obtained triphenylphosphane oxide can find application as a complexing agent, in the extraction of metals (for example Cr, Zn, Fe, Co, Cu, Zn, U), in the production of plasticizers, fire-resistant additives and biologically active substances.

Description

245541

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

Triphenylphosphane is a relatively stable oxidation compound and stronger oxidants are required to oxidize it. For example, PhsPO trinephosphine oxide can be prepared by oxidation of triphenylphosphane with bromine Br 2 in an aqueous medium (Handbuch der prparparenChemie, Stuttgard 1937). The disadvantage of this oxidation method is the non-selectivity of the reaction and the strong corrosive effect of bromine on the apparatus. The selective oxidation of triphenylphosphane is mainly achieved by the use of some complex transition elements (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 [(C 2 H 5 N 2 Z 2, [Fe (mnt) 3] and [(C 2 H 5) 4 N], [Fe (mnt) 2] (mnt = cis-1,2-cyanoethylene-1,2-dithiolite act as catalysts in an acetonitrile solution (T = 298 K), with 15 moles of PI13P and [Fe (mnt) 2] 10 moles of Ph3P being oxidized with 1 mole of catalyst [Fe (mnt) 3-2] (J. Amer. Chem. Soc. 95, No. 4,847, 1973. In the presence of the porphyrin complex TPPFe (II) (TPP = inter-tetrafenyl porphirine anion) the oxidation proceeds in toluene solution at T = 298 KV in the presence of 1 mole of TPPFe (II) at least 27 moles PhsP (J. Amer. Chem. Soc. 102, 5, 945, 1980) More effective catalysts are the triphenylphosphine oxide iron (III) complexes of FeXs (Ph3) 2, wherein X is Cl, Br, NCS, as well as FeXs, wherein X is Cl, Br, NCS and I in an acetonitrile solution at a slightly elevated temperature of No. 205. 483) The disadvantage of said catalytic oxidations is the use of less potent catalysts such as the newly prepared Fe (Ph3PO) 4 (13) 2 compound. For example, when used Fe (Ph 3 PO 3) 3 (13) 2 as a catalyst by concentration of C 1 = 3.8.10 - 3 mol dm-3 priteplote 338 K it is possible to oxidize 1 molcalycalyst to 270 mol PI13P, for example in the presence of 1 mole of catalyst Fe (NCS) 3 ( Ph3PO) 2,100 moles of PI13P. Its high catalytic activity is also indicated by the fact that oxidation of PhsP catalyzed by Fe (Ph3PO) 4 (13) 2 lasted for 50 hours, while in the presence of Fe (NCS) 3 (Ph3PO) 2 it lasted 100 hours.

These shortcomings are eliminated by the process of preparing triphenylphosphane oxide by reacting triphenylphosphane with oxygen according to the invention, wherein the oxidation of triphenylphosphane occurs under the catalytic action of the Fe (Ph3PO) 4 (13) 2 complex, where Ph stands for phenyl, in acetonitrile at T = 290-350 K. The higher effect of the present invention is to use a more efficient Fe (Ph 3 PO) 4 (13) 2 catalyst, resulting in a shorter reaction time, using smaller catalyst concentrations and more catalytic cycles.

The invention is described in the following examples. Example 1

Into a tempered reaction vessel (T = 323 K) purged with oxygen was charged with 1.9 x 10 -4 moles of Fe (Ph 3 PO 3) 3 (13) 2, tri-tri-iodide, tetra (triphenylphosphonate) ferrous, 2. 10 cm @ 3 of acetonitrile are metered in after addition of lov'3 moles of PhsP, triphenylphosphane and, after being connected to an oxygen meter for atmospheric design pressure. By monitoring the dependence of O2 consumption over time, it ensured that the oxidation of triphenylphosphane to triphenylphosphane oxide lasted for 80 minutes, with 95% conversion after 55 minutes. EXAMPLE 2 Example 1 was repeated except that the reaction flask contained a larger amount of triphenylphosphane, i.e. 1.9.10-4 moles of Phe (Ph3PO) 4 (13) 2, 5.10-3 moles of PhsP and 10 cm3 of acetonitrile. By measuring O2 consumption over time, it was found that the triphenylphosphane oxidation lasted for 5.5 hours, with 95% conversion reaching after 200 minutes. EXAMPLE 3 Example 1 was repeated with 12.5 times the higher amount of triphenylphosphane, i.e. the reaction vessel contained 2.5 * 10 < -2 > moles of triphenylphosphane, PhsP, 1.9 * 10 < -4 > moles of complex Fe (Ph3PO) 4 (13) 2 and 10 cm3 of acetonitrile. By measuring the oxygen consumption from time to time, it was found that the PhsP oxidation was carried out for 45 hours, with 80% conversion being achieved in 30 hours. Example 4

The whole experiment was carried out in a tempered reaction vessel (T = 338 K) rinsed with oxygen containing 5.1.times.10@-3 molar triphenylphosphane, 1.9.times.10@5 molar Fe (Ph3 PO) 4 (13) 2 as catalyst and 5 cm @ 3 acetonitrile. By measuring the oxygen demand and the electron spectra, it was found that the oxidation lasted for 4.5 days, with 95% conversion in 3.5 days. Example 5 Example 1 was repeated at a lower temperature (T = 298.5 K) with more complex (Fe (PI 13 PO) 4 (I 3) 21 (5.10 -4 mol), the amount of triphenylphosphane and acetonitrile remained unchanged. (2.10-3 mol, 10 cm3).

Claims (1)

O2 consumption of 245541 was found to oxidize for 7 hours, 95% conversion was achieved in 5.5 hours. Pure triphenylphosphine oxide was recovered from the reaction mixture by precipitation with activated charcoal. The purity of PI13PO was controlled by temperature sinking (T t = 429 K), elemental analysis and infrared spectra in the light (J. Chem. Sov. 1960, 2 199). 6 Analysis results for C 11 H 10 PO [M = 278.29] calculated: 77.68% C, 5.43% H, found: 77.84% C, 5.30% H. The yield was 85%. OBJECTIVE The preparation of triphenylphosphane oxide by the reaction of triphenylphosphane with oxygen is characterized in that the oxidation of triphenylphosphane is carried out at temperatures of 290-350 K under the catalytic effect of the bis (triiodide) iron (III) Fe (Ph3PO) 4 (13) 2, wherein Ph is phenyl, in acetone.