STUDY OF THE REACTION OF 4-CHLOROMETHYLENE-2,6-DI-tert-BUTYLCYCLOHEXA-...
215
The results of the study show that at the con-
servation of the general trend of the reactions
occurring along the above routes, the use of an excess
of ester II with respect to chloromethylenequinone I
shifts the chemical transformations to the formation of
ylides VIII.
3JHH 7.5 Hz), 1.55 s [18H, C(CH3)3], 8.4 q (4H,
3
3
POCH2, JPH = JHH = 7.5 Hz), 4.32 q (6H, P+OCH2,
3
3JPH = JHH 7.5 Hz), 5.08 s (1H, OH), 7.18 s (2H,
C6H2). Found, %: P 11.72, 11.56. C25H46O7P2. Cal-
culated, %: P 11.92.
The product VIIIa shows the characteristic of
ylides the red-purple coloration at melting or dis-
solving in organic solvents (heptane, benzene, chloro-
form).
In the case of the two-fold excess of chloro-
methylenequinone I with respect to ester IIa, the main
direction, in accordance with the above scheme, is the
formation of stilbenequinone XII. Using a double
excess of chloromethylenequinone I to ester IIb does
not shift the process to the formation of stilbene-
quinone, and the main reaction product of the reaction
becomes bisphosphorylated sterically hindered phenol
XIIIb, and a significant portion of the original chloro-
methylenequinone I remains unchanged in the reaction
medium. This fact suggests that the tendency of betain
IIIb to the transformation into the quasi-phosphonium
compound Vb and the subsequent transformation into
the phosphorylated methylenequinone VIb, ylide
VIIIb, and bisphosphorylated sterically hindered
phenol XIIIb is preferred over the transition to the
ylide IVb. Probably, in this case there is an analogy
with the higher activity of phosphinous esters as com-
pared to phosphorous esters in the Arbuzov reaction.
The colored hexane solution after distilling off
volatiles in vacuo gave 0.18 g of product XII, orange,
mp 298–302ºC (toluene) (published data [5]: mp 305–
1
308ºC). H NMR spectrum (CDCl3), δ, ppm: 1.2 d
3
3
[36H, C(CH3)3, J
2 Hz], 6.97 d [1H, CH, JHH
HH
2 Hz], 7.22 s (4H, C6H2), 7.47 d (1H, CH, 3JHH 2 Hz).
b. At 1:1 ratio in hexane. A mixture of the solutions
of 1.26 g (0.005 mol) of I in 15 ml of hexane and 0.83 g
(0.005 mole) of ester IIa in 5 ml of hexane was kept at
room temperature for 48 h, therewith occurred a
gradual precipitation of crystalline product. Compound
VIIIa, 0.84 g (64%), was obtained, mp 125–129ºC
(heptane) containing a little bisphosphonate XIIIa.
After heating the above mixture of solutions of
compounds I and IIa at 50–60ºC for 1 h and removing
the solvent in a vacuum 0.51 g (58%) of compound
VIIIa was isolated, mp 129–135ºC (heptane).
EXPERIMENTAL
1H NMR spectra were recorded on a Tesla BS-
567A instrument (100 MHz), 31P NMR spectra were
recorded on a CXP-100 instrument (operating fre-
quency 36.5 MHz). The chemical shifts of hydrogen
nuclei are given relative to TMS, phosphorus, relative
to 85% H3PO4.
c. At 1:2 a ratio in hexane. A mixture of solutions
of 1.01 g (0.004 mol) of I in 7 ml of hexane and 1.33 g
(0.008 mol) of IIa in 3 ml of hexane was kept at 25ºC
for 24 h. The resulting crystalline product was washed
on the filter with hexane. 8.1 g (51.9%) of compound
VIIIa was obtained, mp 131–133ºC (heptane).
d. At 1:3 ratio. A mixture of 0.85 g (0.0033 mol) of
compound I and 1.66 g (0.01 mol) of ester IIa was
heated at 40ºC for 1 h. The crystals precipitated on
cooling were treated with hexane, 1.10 g (62%) of
compound (VIIIa), mp 121–125ºC (heptane).
Reaction of 4-chloromethylene-2,6-di-tert-butyl-
cyclohexa-2,5-dien-1-one (I) with triethyl phosphite
(IIa). a. At 1:1 ratio. Adding 0.83 g (0.005 mol) of
ester IIa to 1.26 g (0.005 mol) of chloromethylene-
quinone I causes warming and formation of a wine-red
solution. In a few minutes, a crystalline product begins
to precipitate from the reaction mixture. The mixture
was kept at room temperature for 6 h, then treated with
hexane (2×10 ml). 0.83 g (63%) of VIIIa cont-
e. At 2:1 ratio. A mixture of 2.52 g (0.01 mol) of
chloromethylenequinone I and 0.83 g (0.005 mol) of
ester IIa was heated at 60–80ºC for 2h. After 48 h,
0.83 g (38%) of stilbenequinone XII was filtered off,
mp 287–290ºC (toluene) with an admixture of VIIIa,
which was removed after several recrystallizations
from toluene.
1
aminated, according to H NMR spectroscopy, with
compounds XII and XIIIa, was isolated, mp 122–
125ºC (heptane) (published data [4]: mp 131–133ºC).
31P NMR spectrum: δP(1) 29.20 ppm (2JPP 91.25 Hz)
(phosphonate), δP(2) 50.13 ppm (2J 91.25 Hz) (ylide).
1H NMR spectrum (CDCl3), δ, ppm: 1.32 t (6H,
Reaction of 4-chloromethylene-2,6-di-tert-butyl-
cyclohexa-2,5-dien-1-one (I) with ethyl diphenyl-
phosphinite (IIb). a. At 1:2 ratio in hexane. The
3
POCH2CH3, JHH 7.5 Hz), 1.40 t (9H, P+OCH2CH3,
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 82 No. 2 2012