On the reaction of 4-chloromethylene-2,6-di-tert-buthylcyclohexa- 2,5-dien-1-one with P(III) acids esters

Full text of DOI:10.1134/S1070363209010307

ISSN 1070-3632, Russian Journal of General Chemistry, 2009, Vol. 79, No. 1, pp. 155–156. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © М.B. Gazizov, R.K. Ismagilov, L.P. Shamsutdinova, R.F. Karimova, R.B. Zamaletdinov, О.G. Sinyashin, 2009, published in Zhurnal
Obshchei Khimii, 2009, Vol. 79, No. 1, pp. 159–160.
LETTERS
TO THE EDITOR
On the Reaction of 4-Chloromethylene-2,6-di-tert-
buthylcyclohexa-2,5-dien-1-one with P(III) Acids Esters
М. B. Gazizova, R. K. Ismagilova, L. P. Shamsutdinovaa,
R. F. Karimovaa, R. B. Zamaletdinova, and О. G. Sinyashinb
aKazan State Technological University,
ul. K. Marksa 68, Kazan, Tatarstan, 420015 Russia
e-mail: mukattisg@mail.ru
bArbuzov Institute of Organic and Physical Chemistry, Kazan Research Center,
Russian Academy of Sciences, Kazan, Tatarstan, Russia
Received April 11, 2008
DOI: 10.1134/S1070363209010307
Proceeding with investigations on reactions of
organic halides with aprotic reagents [1, 2], we
pioneered in studying reactions of 4-chloromethylene-
2,6-di-tert-butylcyclohexa-2,6-dien-1-one I (chloro-
methylenequinone) with P(III) acids esters, such as
triethyl phosphite IIа and ethyl diphenylphosphinite
IIb. Phosphorylated ylides VII were established to be
the main products of the reaction of chloromethylene-
quinone I with esters II in a 1:2 ratio. We suppose that
ylide VII is formed by the following two-stage scheme:
t-Bu
t-Bu
_
+
O
CH P(OEt)R2
O
CHCl + R2POEt
Cl
t-Bu
t-Bu
I
III
II
t-Bu
t-Bu
_
+
O
CH P(OEt)R2Cl
P(O)R2 + EtCl
O
CH
t-Bu
t-Bu
IV
V
t-Bu
t-Bu
HO
t-Bu
_
_
C
+
+
V + II
O
CH P(OEt)R2
P(OEt)R2
P(O)R2
P(O)R2
VII
t-Bu
VI
II–VII: R = EtO (a), Ph (b).
In the first stage of the reaction, ester II adds to a
highly electrophilic chloromethylenequinone I to form
betaine intermediate III which eliminates chloride
anion through intramolecular nucleophilic substitution
and transforms into quasiphosphonium compound IV.
The latter is stabilized into phosphorylated methyl-
enequinone V in accordance with the scheme of the
second stage of the Arbuzov reaction.
155

156
GAZIZOV et al.
At the second stage of the reaction, ester II adds to
methylenequinone to form bisphosphorylated
betaine VI which transforms into phos-phorylated
b. After mixing solutions of 1.06 g of Va in 3 ml
V
of hexane and 0.5 g of triethylphosphite in 3 ml of
hexane abundant product crystallization occurred.
After 24 h, the product was filtered off. Yield 1.32 g
(84.6%), mp 135–136°С (heptane).
ylide VII through 1,6-proton shift [3–5].
Ylide VIIа was earlier prepared [5] by boiling
compounds Va and IIа in benzene for 1.5 h. Our
studied reactions proceed under milder conditions (20–
25°С), and, therefore, we reproduced the second stage
of the proposed scheme as a model experiment. A few
minutes after mixing hexane solutions of equimolar
amounts of compounds Va and IIа or Vb and IIb,
crystallization of products VIIa or VIIb, respectively,
occurred at room temperature.
[(3,5-Di-tert-butyl-4-hydroxyphenyl)(diethoxy-
phosphinoyl)methylene](ethoxy)diphenyl-λ5-phos-
phorane (VIIb). а. From a mixture of solutions of
0.51 g of compound I in 3 ml of toluene and 0.92 g of
ethyl diphenylphosphinite (20–25°С, 24 h). Yield
1
0.73 g (57.0%), mp 210–212°С (toluene). Н NMR
spectrum (CDCl3), δ, ppm: 1.30 s [18Н, С(СН3)3],
3
3
1.70 t (3Н, СН3, JHH 7 Hz), 4.80 q (2Н, СН2, JРH
=
3JHH 7 Hz), 4.95 s (1Н, ОН), 6.92 d (2Н, С6Н2, 2JHH 2 Hz),
7.40–8.10 m (20Н, С6Н5). Found, %: Р 9.45, 9.30.
С41Н46О3Р2. Calculated, %: Р 9.57.
The structure of the synthesized compounds was
proved by 31Р NMR spectroscopy. The 31Р NMR
spectra of compounds VIIа and VIIb contain two
doublet signals from nonequivalent phosphorus atoms:
VIIa: δP(1) 29.20 ppm (2JPP 91.25 Hz) (phosphonate Р);
δP(2) 50.13 ppm (2JPP 91.25 Hz) (ylide Р); VIIb: δP(1)
27.82 ppm (2JPP 49.4 Hz) (phosphine oxide Р), δP(2)
50.49 ppm (2JPP 49.4 Hz) (ylide Р).
b. From a mixture of 0.84 g of compound Vb in
10 ml of toluene and 0.46 g of ethyl diphenyl-
phosphinite in 5 ml of toluene. Yield 1.06 g (81.5%),
mp 213–214°С (toluene).
The 1Н NMR spectra were recorded on a Tesla BS-
567A spectrometer (100 MHz, TMS). The 31Р NMR
spectrum was registered on a СХР-100 instrument
(36.5 МHz, 85% Н3РО4).
Ylides VIIа and VIIb are colorless crystalline sub-
stances; when they melted or dissolved in heptane, ben-
zene, toluene, or chlorofom, a red-purple color appeared.
4-Chloromethylene-2,6-di-tert-butylcyclohexa-2-
REFERENCES
dien-1-one was prepared by the procedure in [6], mp
1
59–61°С. Н NMR spectra (ССl4 + CDCl3), δ, ppm:
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[(3,5-Di-tert-butyl-4-hydroxyphenyl)(diethoxy-
phosphinoyl)methylene]triethoxy-λ5-phosphorane
(VIIa). а. A mixture of solutions of 1.01 g of
compound I in 7 ml of hexane and 1.33 g of tri-
ethylphosphite in 3 ml of hexane was kept at 20–25°С
for 24 h. The product crystallized and was washed with
hexane. Yield 1.08 g (51.9%), mp 131–133°С (heptane)
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1
(published data [5]: mp 133–135°С). Н NMR spec-
3
trum (CDCl3), δ, ppm: 1.32 t (6Н, РОСН2СН3, JHH
5. Gross, H., Keitel, J., and Costisella, B., Phosphorus,
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3
3
Sulfur Silicon, 1992, vol. 70, p. 331.
6. Egidis, F.M., Popov, L.K., Volod’kin, А.А., Er-
shov, V.V., and Volkotrub, M.N., Izv. Akad. Nauk SSSR,
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[18Н, С(СН3)3], 4.08 q (4Н, РОСН2, JРH = JHH
7.5 Hz), 4.32 q (6Н, Р+ОСН2, 3JРH = 3JHH 7.5 Hz), 5.08
s (1Н, ОН), 7.18 s (2Н, С6Н2). Found, %: Р 11.80,
11.50. С25Н46О7Р2. Calculated, %: Р 11.92.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 79 No. 1 2009