THE SYNTHESIS OF ORGANOPHOSPHORUS COMPOUNDS

WITH A HEXACOORDINATED PHOSPHORUS ATOM

STARTING FROM WHITE PHOSPHORUS

M. I. Kabachnik, D. I. Lobanov, and P. V. Petrovskii

UDC 542.91:547.1'118

The reaction of 3,5-di-tert-butylorthoquinone with white phosphorus (P4) under UV irra- diation has been used for the first time for synthesis. The formation of free radicals with the hexacoordinated phosphorus atom [I] has been observed in thereaction earlier. Illumina- tion with visible light and refluxing of the benzene solution of orthoquinone, P4, and Et3N (molar ratio 1:0.25:2) for 8 h gave a mixture of the isomers of triethylammonium tris(3,5- di-tert-butyl-l,2-phenylenedihydroxy)phosphorate (I) (10%), mp (decomp.) 135-152~ (in ben- zene)(isomer ratio ~i:i according to 31p NMR). The structure of (I) was confirmed by ele- mental analysis, the mass spectrum (ions of the type L2P +, m/e 471 and LP + m/e 251) and the 3~p NMR spectrum (two singlets at-83.54 and-83.74 ppm, respectively)

+ O

P.BNEta (I) / \ 3

x 0

In order to increase the yield of (I), 3,5-di-tert-butylpyrocatechol was used as the reducing agent instead of Et3N. Under the above conditions and using the molar ratio ortho- quinone:pyrocatechol:P~ = 5:1:0.5 the phosphorane (II) is formed. The addition of Et3N gives a precipitate of the phosphorate (I) (overall yield 66-68%). Depending on the condi- tions of EtaN addition, one of the phosphorate (I) isomers can be obtained. In one case the addition of Et3N to a solution of the phosphorane (II) gave, under vigorous stirring and cooling to 20~ the isomer with mp (decomp.) 147-152 ~ (benzene)* and 6 ~P-83.69 ppm. When Et3N is added in 2 h at 80 ~ under illumination, the second isomer is formed with mp (decomp.) 144-150 ~ (benzene),*~ 3~P-83.73 ppm. A mixed sample melts (with decomposition) at 144-152~ * When the solutions of both isomers are mixed, two signals at-83.64 and-83.77 ppm are observed in the 31p NMR spectrum.

+ +

x O HO X

(II)

The 31P-{~H} NMR spectra have been obtained on a Bruker HX-90 spectrometer (36.43 MHz) in acetonitrile, C ~0.i M, at 30~ using 85% H3PO4 as an external standard.

LITERATURE CITED

i. A. I. ProkofVev, A. A. Khodak, N. A. Malysheva, N. N. Bubnov, S. P. Solodovnikov, I. S. Belostotskaya, V. V. Ershov, and M. I. Kabachnik, Dokl. Akad. Nauk. SSSR, 240, 358 (1978).

*In the case of rapid heating.

Institute of Heteroorganic Compounds, Academy of Sciences of the USSR, Moscow. Trans- lated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. i0, p. 2398, October, 1979. Original article submitted July i0, 1979.

0568-5230/79/2810-2223507.50 �9 1980 Plenum Publishing Corporation 2223