DE1198819B - Process for the production of primary and secondary phosphines - Google Patents

Description

Process for the production of primary and secondary phosphines general formula R (R ') R "P = 0 in which R, R' and R" are identical or different alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkaryl radicals, where R and R 'together with the phosphorus atom the phospholine ring of the general formula can form with an organic silicon compound which contains one or more Si-H bonds at elevated temperature. In this reaction, the difficult to reducible P = O bond is reduced with formation of the phosphine.

The present invention relates to a further embodiment this process for the production of primary and secondary phosphines. The invention is characterized in that one for the production of primary or secondary Phosphines of the general formula RPH2 or R'R "PH is a phosphonic or phosphinic acid of the general formula RP (O) (OH) 2 or R '(R ") P (O) OH, in which R, R' and R" are optionally denote hydrocarbon radicals substituted by amino or alkoxy groups, where R 'and R "together with the phosphorus atom form the phospholane ring or the optionally by the methyl group in the 3- or in the 3- and 4-position substituted phospholine ring or their ester or their salt with the organic silicon compound implements. In this implementation, not only is the P = O bond, but also the P - 0 - H bond is reduced.

According to the invention, for. B. substituted by the amino group Produce phosphines, which by the usual methods, for. B. by means of Grignard compounds, are difficult to access. Examples of suitable starting substances are e.g. B. methyl, Ethyl, propyl, propenyl, isopentyl, phenyl, cyclohexyl and benzyl phosphonic acids. Examples of suitable phosphinic acids are dimethyl, diethyl, diphenyl, methylphenyl, Dibenzyl- and dicyclohexylphosphinic acid as well as l-oxo-l-oxyphospholine and l-oxo-l-oxy-3-methylphospholine. Instead of the free Phosphonic or phosphinic acids can be their esters or salts be applied. The process according to the invention can advantageously be used for production of primary phosphines from phosphonic acids or their esters or salts.

The reduction is carried out with an organic silicon compound which contains one or more Si-H bonds. Diphenylsilane or hydrogen polysiloxanes, in particular methyl hydrogen polysiloxane, are preferably used. These polysiloxanes contain a plurality of R. - Si - 0 - groupings H (R = H or a hydrocarbon radical, e.g. the methyl radical). These groupings can either be in the form of an uninterrupted polysiloxane chain or be interrupted, e.g. B. by glycol residues: -Si-0-CC-0-Si-0- | The reduction is carried out at elevated temperatures, ie the temperature will generally be above 100.degree. C., preferably between 150 and 200.degree. C., in particular when using diarylsilanes, such as, for example, diphenylsilane works advantageously at temperatures between 150 and 300 "C. A reaction time of 1 to 5 hours is generally sufficient. The reduction can be carried out either with an inert solvent or without a solvent. Suitable inert solvents are e.g. B. naphthalene, benzene, toluene, glycol diethyl ether, diethylene glycol dimethyl ether and diphenyl ether.

Example 1 26.7 g of methyl dibutylphosphinate (0.15 mol) and 41.4 g of diphenylsilane (0.225 mol) are in an N2 atmosphere at 150ob for 4 hours warmed up.

It is then distilled. The first fraction at 68 to 76 "C yields 16.8 g of dibutylphosphine.

A sample of the phosphine with 20 g of phenyl isocyanate was used for characterization reacted in 80 ml of benzene. 30.2 g of dibutyl- [phenylcarbamoyl] -phosphine crystals fell (79.2% based on the methyl dibutylphosphinate used), which according to Recrystallization from ethanol had a temperature of 98 to 99 "C.

Analysis: ClsH2oNop (265).

Calculated ... C 67.98, H 9.13, N 5.29, P 11.71; found ... C 67.3, H 9.0, N 5.5, P 12.00.

Example 2 34.8 g of methyl diphenylphosphinate (0.15 mol) and 41.4 g of diphenylsilane (0.225 mol) are in an N2 atmosphere for 4 hours up to Heated to 190 "C and then distilled. At 105 to 115" C and 0.35 Torr went 16.8 g diphenylphosphine (59,010) over.

A sample of this phosphine was used for characterization with phenyl isocyanate implemented, whereby crystals with a mp of 136 to 137 ° C were obtained. Mixed melting point with authentic diphenyl- [phenylcarbamoyl] -phosphine showed no depression.

Example 3 21.8 g (0.15 moles) of 1-oxo-1-hydroxy-3,4-dimethylphospholine and 41.4 g (0.225 mol) of diphenylsilane were heated to 150 to 190 "C for 4 hours and then distilled. At 146 to 148 "C, 13.8 g (810 Ω) of 3,4-dimethylphospholine went above.

A sample of this phosphine was used for characterization with phenyl isocyanate reacted and 12.4 g of 3,4-dimethyl-1-phenylcarbamoylphospholine obtained from F. 110 "C.

Analysis: ClsH16NOP (233).

Calculated ... C 67.01, H 6.92, N 6.01, P 13.32; found ... C 67.4, H 6.8, N 6.2, P 13.0.

Example 4 20.7 g of n-butylphosphonic acid (0.15 mol) and 41.1 g of diphenylsilane (0.225 mol) were heated to 150-190 "C under a nitrogen atmosphere. On the reflux condenser a distillation bridge was placed, the template with dry ice in chloroform was cooled.

After 4 hours, 5.7 g of butylphosphine were in the receiver (42%) Characterization, a sample of this phosphine was reacted with phenyl isocyanate and 5 g of bis [phenylcarbamoyl] -n-butylphosphine, m.p. 84 "C.

Analysis: Cl8H2IN202P (328).

Calculated ... C 65.91, H 6.45, N 8.54, P 9.46; found ... C 65.9, H 6.4, N 8.8, P 9.5.

Example 5 43 g (7.2 equivalents) of methyl hydrogen polysiloxane and 19.4 g (0.1 mol) of diethyl butylphosphonate are placed in a three-necked flask, which is equipped with a reflux condenser with attached cold trap and a vibromixer is, with nitrogen bubbling through, at 200 "C for 3 hours and up to 2 hours 275 "C. After this time there are 9.8 g of butylphosphine in the cold trap.

A sample of this phosphine was used for characterization with phenyl isocyanate reacted in benzene in the presence of triethylamine as a catalyst and bis- [phenyl-carbamoyl] -n-butylphosphine obtain.

Claims (2)

Claims: 1. Further development of the method according to the patent application S80694 IVb / 12 o for the production of tertiary phosphines by reducing the corresponding Phosphine oxides with an organic silicon compound containing one or more Si H contains bonds, at elevated temperature, characterized in that one for Production of primary or secondary phosphines of the general formula RPH2 respectively. R '(R ") PH the corresponding phosphonic resp. Phosphinic acid of the general formula RP (O) (OH) 2 or R '(R ") P (O) OH, in which R, R 'and R "are hydrocarbon radicals optionally substituted by amino or alkoxy radicals mean, where R 'and R "together with the phosphorus atom represent the phospholane ring or those optionally substituted by the methyl group in the 3- or in the 3- and 4-positions Can form phospholine ring, or its ester or its salt with the organic Silicon compound converts. 2. The method according to claim 1, characterized in that the Reaction with a diarylsilane at a temperature between 150 and 200 "C undertakes. Documents considered: German Auslegeschrift 1 031 520; U.S. Patent 2,727,880; Journal of inorganic and general chemistry, 299, 1959, 58 to 68; Helvetica chimica acta, 36, 1953, pp. 142 to 144; Comtes rendus hebdomadaires des seances de l'académie des sciences, 245, 1957, pp. 906, 907.