540
MATVEEVA et al.
of the systematically quenched reflections the
experimental set of the measured reflections was
2526 with (I) > 2 (I). The structure was solved by
the direct method and was refined by full-matrix
least-squares procedure with respect to F2 with the
use of SHELXL-97 software [21] in anisotropic
approximation for the nonhydrogen atoms. All
hydrogen positions were found geometrically and
were not refined considering the quality of the
crystal. The final coordinates and thermal factors of
atoms in the structure under study are given in
Table 3. The final value of R-factor 4.9% for 2526
reflections with (I) > 2 (I), parameter good of fit
equals to 0.996, the structure of anion and cation are
given on the figure.
5 ml of ethyl ether was added, and the stirring was
continued for 1 h more. The separated precipitate was
filtered off, washed with ether, and dried in air. The
yield of compound I 40%, mp 190 191 C.
Method 2. To a solution of 5 g (0.013 mol) of
ethoxycarbonylmethylenetriphenylphosphonium
chloride (II) in 19 ml of water was added 5 ml at 80%
solution of NaOH till pH 8. The separated precipitate
was filtered off, washed with water, dried, and
recrystallized from ethanol (15 ml), washed with
ether, and dried. We obtained 3.5 g (77%) of ylide
III, mp 112 113 C [22].
To a solution of 3.5 g (0.01 mol) of ylide III in
5 ml of methanol cooled to 0 C was added a solution
of 3.25 g (0.01 mol) of phenyliodoso diacetate in
19 ml of methanol maintaining the temperature of the
reaction mixture below 5 C. Then 2.5 ml of 40%
HBF4 solution was added maintaining the temperature
of the reaction mixture within 0 5 C range. The
mixture was stirred for 1 h, then 10 ml of ethyl ether
was added, and the stirring continued for 1 h more.
The separated precipitate was filtered off and washed
with ether. We obtained 5.3 g (85%) of ylide I,
Purification of solvents. Methanol. To 1 l of
methanol was added 5 g of magnesium turnings, on
completion of reaction the methanol was refluxed for
2 h and distilled. Benzene was refluxed with metallic
sodium and distilled. Acetonitrile was boiled several
times till it stopped to take color and then distilled. It
was kept om molecular sieves 3A.
Ethoxycarbonylmethylenetriphenylphosphon-
ium chloride (II) [22]. A solution of 0.01 mol of tri-
phenylphosphine and 0.11 mol of alkyl chloroacetate
in 10 ml of anhydrous acetonitrile was boiled till
complete consumption of triphenylphosphine (TLC
monitoring). This process takes about 48 h. The
solution was concentrated to a half of its volume, and
ethyl acetate was added till the solution turned slight-
ly turbid. Then the reaction mixture was left standing
for 12 h to the end of crystallization. The salt was
filtered off, washed with ethyl acetate, and dried in a
vacuum. Yield 90%.
1
mp 190 191 C. IR spectrum, , cm : 1600, 1570,
1486. Found, %: C 52.44; H 3.89; I 20.55.
C28H25BF4IO2P. Calculated, %: C 52.66; H 3.90;
I 19.89.
This study was carried out under financial support
of CRDF, grant RC2-2216, and Russian Founda-
tion for Basic Research, grant no. 02-03-32163.
One of the authors (N.S.Zefirov) is grateful to
A.V. Humboldt Foundation and to Professor
R. Gleiter, University of Heidelberg for possibility to
carry out research in this field.
Phenyliodoniumethoxycarbonylmethylenetri-
phenylphosphorane borofluoride (I). Method 1. To
5 ml of anhydrous methanol was gradually added
0.01 mol of metallic sodium, and after its complete
dissolution was gradually added dropwise a solution
of 0.01 mol of phosphonium salt II in 5 ml of
anhydrous methanol. The reaction mixture was
cooled with ice water for 1 h till complete precipita-
tion of sodium chloride. The solution of ylide III was
filtered from the NaCl precipitate and was used
directly in the next stage of the reaction. Ylide III
solution was cooled to 0 C, and a solution of
0.01 mol of phenyliodoso acetate in 8 ml of
anhydrous methanol was added controlling the addi-
tion rate so as the reaction temperature did not exceed
0 C. Then 0.01 mol of 40% solution of HBF4 was
added maintaining the temperature at 0 C. The solu-
tion was stirred at the same temperature for 1 h, then
REFERENCES
1. Stang, P.J. and Zhdankin, V.V., Chem. Rev. 1996,
vol. 96, p. 1123.
2. Zhdankin, V.V. and Stang P.J., Polycoordinate Iodine
Compounds, in Chemistry of Hypervalent Com-
pounds , Akiba, K., Ed., New York: Wiley, 1999,
p. 327.
3. Zefirov, N.S. and Koz,min, A.S., Acc. Chem. Res.,
1985, vol. 18, p. 154.
4. Brel,, V.K., Gakh, A.A., Zhdankin, V.V., Zefi-
rov, N.S., Koz,min, A.S., Korkin, A.A., Kutate-
ladze, T.G., Keipl, R., Lermontov, S.A., Plokhikh,
I.G., Safronov, S.O., Steng, P.Dzh., and Chovni-
kova, N.G., Dokl. Akad. Nauk, SSSR, 1990, vol. 313,
p. 1131.
5. Zefirov, N.S., Zhdankin, V.V., Dan,kov, Yu.V.,
Sorokin, V.D., Semerikov, V.N., Koz,min, A.S.,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 39 No. 4 2003