DE1223838B - Process for the production of primary and secondary phosphines - Google Patents

Description

Process for the production of primary and secondary phosphines Es is known to include halophosphines, phosphine dihalides and phosphine oxides the cyclic phosphine oxides by lithium aluminum hydride or aluminum hydride to reduce the corresponding primary, secondary or tertiary phosphines. (Journal for inorganic and general chemistry, Vol. 299 [1959], p. 58, and Ho u b e n-W e y 1, Methods of Organic Chemistry, 12/1, 1963, pp. 60 and 61). Also the reduction of phenyldichlorophosphine with lithium alanate and that of phenylphosphonic acid dichloride with lithium alanate or the milder acting lithium boranate is from J. Am.

Chem. Soc., 74, 562 and 3414-3415 (1952).

The reducing agents used there are, however, self-igniting, when they come into contact with air and tend to explode in the presence of water Decomposition. When using these hydrides, the reduction starts with strong self-heating of the reaction mixture and must therefore be handled very carefully. the Processes are therefore large-scale because of the dangers involved, if at all, so just extremely difficult to handle.

It is also known to produce tertiary phosphines Reduction of the corresponding phosphine oxides using silicon compounds, which one or more Si-H bonds, optionally also Si-halogen bonds included, to be carried out (laid out documents of Belgian patent 635 518). The silicon compound is generally used in such amounts, that for each oxygen atom bonded to phosphorus 1.5 to 3 bonded to silicon Hydrogen atoms are present.

According to a proprietary, out-of-the-art proposal you can use the required amount of these halogen-containing reducing agents with the same yield in the reduction of mono- and dihalophosphines and their corresponding ones Reduce phosphine oxides by half if you do the reduction in the presence of tertiary Amines. The amine can be used in a simple manner during work-up to be recovered.

The invention now relates to a method for producing primary and secondary phosphines of the general formula R, (R3PH, in which R1 is optionally alkyl substituted by alkoxy, alkyl mercapto, acyl, amido or amino radicals, Is alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or alkaryl radical, R2 is R1 or is hydrogen or R1 and R2 together are optionally one Phosphorus substituted by alkyl radicals pholine or phospholane ring mean through Reduction of phosphorus compounds of the general formula R1 (R2) (R3) P (= O) n, in which R1 and R2 have the meaning given above or either Rl or R2 is a chlorine or bromine atom, RS represents chlorine or bromine and n represents zero or one, which characterized in that the reduction is carried out with a silicon-hydrogen compound of the general formula RR5) (R6) SiH, in which R4, R5 and R6 are identical or different are and aryl, alkyl, alkoxy radicals or hydrogen and at least one of the substituents R4, R5 and R6 represent chlorine or bromine atoms in the presence of a tertiary amine at temperatures between 50 and 3500 ° C., in particular at 50 to 100 ° C., carried out.

The reaction can be carried out in the presence of solvents such as inert hydrocarbons or ethers and especially those that have a high boiling point will. Benzene, toluene, decalin, tetrahydrofuran and dioxane may be mentioned.

As tertiary amines, for example, trialkylamines, dialkylanilines, Pyridine or alkyl-substituted pyridines are used. Such proportions are thereby used that on a P 0 or P-halogen bond of the molecule of the phosphorus compound 0.7 to 1.5, in particular about 1 equivalent, of the halogen-containing silicon-hydrogen compound as 0.7 to 1.5, in particular about 1 equivalent of tertiary amine comes. As a by-product the reaction creates the HCl or HBr salt of the amine, which is easily separated whereupon the amine can be recovered.

The choice of reaction temperatures in the range from 50 to 350 "C will be on the nature of the substituents on the phosphorus compound and the choice of reducing agent influenced. When using z. B.

Silicochloroform gives good results at 50 to 100 "C, without that the reaction is particularly violent or dangerous. The silicon compounds used are easy-to-use and harmless compounds made according to newer methods can be manufactured inexpensively. It should be particularly emphasized that the Process according to the invention phosphines with unsaturated substituents from the corresponding Starting materials can be obtained without saturation of the C / C double bonds he follows. So z. B. the unsaturated 1-chloro-1-oxo-phospholines to the phospholines, but not reduced to phospholanes.

Examples 1. Reduction of di-n-butylphosphinic acid chloride 19.65 g (0.1 mole) di-n-butylphosphinic acid chloride, 30 g (0.22 mole) silicochloroform and 22 g (0.22 mol) of triethylamine were. refluxed with 250 ml of benzene for 2 hours. 100 ml of 300 ml of NaOH were then added, the organic phase was separated off, washed with water and dried.

The benzene solution was fractionally distilled.

Yield 9.2 g = 63% of the theory of di-n-butylphosphine with a range of 14 70 to 890 C. All operations were carried out under nitrogen.

2. Reduction of diphenylchlorophosphine 22 g (0.1 mol) diphenylchlorophosphine, 15 g (0.11 mol) of silicochloroform and 11 g (0.11 mol) of triethylamine were in 80 ml Benzene refluxed for 2 hours. Then 80 ml of 300/0 washer NaOH is added, the organic phase is separated off, washed, dried and fractionated distilled.

Yield 14 g = 750 / the theory diphenylphosphine of 12 155 "C. All operations were carried out under nitrogen.

3. Reduction of phenyldichlorophosphine 36 g (0.2 mol) phenyldichlorophosphine, 30 g of silicochloroform (0.2 mol) and 22 g (0.22 mol) of triethylamine were in 250 ml of benzene refluxed for 2 hours. After adding 150 ml of 200% of the NaOH the organic phase separated, washed and dried. The benzene solution was fractionally distilled. Yield 12g = 550 /, the theory Phenylphosphhln vom Kr.14 600 C. All operations were carried out under nitrogen.

4. Reduction of 1-oxo-1-chloro-3-methyld 2 - phospholine 24 g (0.2 Mol) of the phospholine and 44 g (0.44 mol) of triethylamine were in 50 mol absolute Benzene dissolved. Thereto, 44.4 g (0.33 mol) of silicochloroform was added. The reaction mixture was refluxed for 2 hours. After cooling, 75 ml of 400% were aqueous sodium hydroxide solution added, the organic phase separated, with dilute Washed with HCl and water and dried over CaCl2. the benzene solution was fractionally distilled. At 122 ° C./760 torr, 6.1 g 450/0 of the theory 3-methyl-da-phospholine went above. All operations were carried out under nitrogen.

5. Reduction of n-butyl-phenylphosphinic acid chloride 42.5 g (0.2 mol) n-butyl-phenyl-phosphinic acid chloride, 59.6 g (0.44 mol) silicochloroform and 40 g (0.4 mol) of triethylamine were refluxed for 2 hours in 500 mol of benzene. 150 mol of 200/0 sodium hydroxide solution were then added to the organic phase separated, washed, dried and fractionally distilled. Yield of n-butylphenylphosphine: 19.6 g = 600/0 of the theory from KP.2 to 30 85 to 95 "C. It was under nitrogen worked.

6. Reduction of o-dianisylphosphinic acid chloride 59.3 g (0.2 mol) o-dianisylphosphinic acid chloride; 54.2 g (0.4 mol) of silicochloroform and 40 g (0.4 Mol) triethylamine were refluxed for 2 hours in 150 ml of benzene. Afterward 100 ml of 200/0 sodium hydroxide solution were added, the organic phase was separated off, washed, dried and concentrated in vacuo. The residue was recrystallized from ethanol. Yield of di-o-anisylphosphine 14.2 g = 290 / o of the theory of melting point 138 ° C.

7. Reduction of di-m-tolylphosphinic acid chloride 35.5 g of di-m-tolylphosphinic acid chloride, 29.8 g of silicochloroform and 22.9 g of triethylamine were treated with 200 ml of benzene for 2 hours refluxed.

200 ml of 200 ml of the sodium hydroxide solution were then added to the organic Layer separated and fractionally distilled in vacuo. Yield of dim-tolylphosphine: 9 g = 31 = 2% of the theory of Kpvowol 1550C.

It was worked under N2.

Claims (1)

Claim: Process for the production of primary and secondary Phosphines of the general formula R1 (R2) PH, in which R1 is an optionally by Alkoxy, alkyl mercapto, acyl, amido or amino radicals of substituted alkyl, alkenyl, Cycloalkyl, cycloalkenyl, aryl, aralkyl or alkaryl radicals, R2 is the same R1 is or is hydrogen or R1 and R2 together are optionally one by alkyl radicals substituted phospholine or phospholane ring mean through Reduction of phosphorus compounds of the general formula R1 (R2) (R3) P (= O) », in which R1 and R2 have the meaning given above or either R1 or R2 is a chlorine or bromine atom, R2 represents chlorine or bromine and n represents zero or one, thereby characterized in that the reduction with a halogen-containing silicon-hydrogen compound of the general formula R4 (Rb) (R6) SiH, in which R4, R5 and R6 are identical or different are and aryl, alkyl, alkoxy radicals or hydrogen and at least one of the substituents R4, R5 and R6 mean chlorine or bromine atoms in the presence of a tertiary amine at temperatures between 50 and 350 "C, especially at 50 to 100 "C, performed. ~~~~~~~ Publications taken into consideration: Documents laid out Belgian Patent No. 635,518; Journal of inorganic and general chemistry, 299: 58 (1959); H o u b e uWe y 1, Methods of Organic Chemistry 12/1 (1963), Pp. 60 and 61; J. Am. chem. Soc., 74: 562 and 3414-3415 (1952).