Synthesis of (o-carborane-1,2-diyl)dipropanoic acid and its derivatives

Article abstract of DOI:10.1023/A:1021665510491

Hydrolysis of 1,2-bis(cyanoethyl)-o-carborane easily available by cyanoethylation of o-carborane gives (o-carborane-1,2-diyl)dipropanoic acid. The corresponding acid dichloride, diamide, dianilide, dibenzophenone, and diol were prepared from it by typical

Full text of DOI:10.1023/A:1021665510491

Russian Journal of General Chemistry, Vol. 72, No. 9, 2002, pp. 1383 1385. Translated from Zhurnal Obshchei Khimii, Vol. 72, No. 9, 2002,
pp. 1468 1470.
Original Russian Text Copyright
2002 by Guseva, Vinogradova, Zakharkin.
Synthesis of (o-Carborane-1,2-diyl)dipropanoic Acid
and Its Derivatives
V. V. Guseva, L. E. Vinogradova , and L. I. Zakharkin
Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Moscow, Russia
Received November 8, 2000
Abstract Hydrolysis of 1,2-bis(cyanoethyl)-o-carborane easily available by cyanoethylation of o-carborane
gives (o-carborane-1,2-diyl)dipropanoic acid. The corresponding acid dichloride, diamide, dianilide, dibenzo-
phenone, and diol were prepared from it by typical procedures.
Up to now only two carborane-1,2-dicarboxylic
acids have been known: o-carborane-1,2-dicarboxylic
Acid II is formed in a good yield. It is a white
crystalline substance, mp 244 245 C. This acid can
be regarded as a derivative of suberic acid, in which
two o-carborane carbons are incorporated into the
aliphatic chain of suberic acid. These two acids have
different molecular weights; thus, acid II contains the
polyhedral group B10H10 instead of four hydrogen
atoms. That is why it was interesting to compare
properties of derivatives of acids II and III. To this
end, some reactions of the carboxy groups of acid II
were studied. Heating of compound II with thionyl
chloride acid gives dichloride IV. The reaction is
similar to that with suberic acid. Dichloride IV, like
aliphatic dichlorides, slowly hydrolyses in air.
and (o-carborane-1,2-diyl)diacetic acids [1].
All
attempts to prepare dicarboxylic acids with a longer
chain have been unsuccessful. Kalinin et al. [2] have
found that o-carborane is easily cyanoethylated to give
1,2-bis(cyanoethyl)-o-carborane I whose transforma-
tions had not been studied.
In the present work we effected hydrolysis of di-
nitrile I in sulfuric acid to obtain the previously un-
known (1-o-carborane-1,2-diyl)dipropanoic acid (II)
according to the following scheme.
CNCH2CH2C CCH2CH2CN
B10H10
II + 2SOCl2
ClCOCH2CH2C CCH2CH2COCl
I
B10H10
IV
H2SO4 + H2O
HOOCCH2CH2C CCH2CH2COOH
150 C
B10H10
II
Starting with dichloride IV, we prepared diamide
V, dianilide VI, and diethylamide VII.
PhNHCOCH2CH2C CCH2CH2CONHPh
NH2COCH2CH2C CCH2CH2CONH2
B10H10
B10H10
VI
V
NH3
PhNH2
IV
C6H6
AlCl3
(C2H5)2NH
(C2H5)2NCOCH2CH2C CCH2CH2CON(C2H5)2
PhCOCH2CH2C CCH2CH2COPh
B10H10
B10H10
VII
VIII
Deceased.
1070-3632/02/7209-1383$27.00 2002 MAIK Nauka/Interperiodica

1384
GUSEVA et al.
Moreover, the dichloride easily enters the Friedel
jet-pump vacuum. The solid residue was crystallized
from hexane to obtain 3.1 g (92%) of compound IV,
mp 87 88 C.
Crafts reaction with benzene to form diketone VIII.
These reactions proceed similar to those of suberic
acid dichloride.
(o-Carborane-1,2-diyl)dipropanamide (V).
Acid dichloride IV, 0.1 g, was dissolved in 8 ml of
dry benzene, and dry ammonia was passed through it
until complete saturation. The residue was dissolved
in water and extracted with three portions of ether.
The ether was removed, and the residue was crystal-
lized from toluene, mp 161 162 C. Found, %: C
33.28; H 7.80; B 37.68; N 9.90. C8H22B10N2O2.
Calculated, %: C 33.56 H 7.69; B 37.76; N 9.79.
Reduction of compound II with lithium aluminum-
hydride in ether gives crystalline 1,2-bis(3-hydroxy-
propyl)-o-carborane (IX).
LiAlH4
II
HOCH2CH2CH2C CCH2CH2CH2OH
ester
B10H10
IX
Dinitrile I was reacted with C6H5MgBr in ether to
obtain, after hydrolysis, diketone VIII. The same re-
action direction is characteristic of aliphatic dinitriles.
(o-Carborane-1,2-diyl)dipropananilide (VI).
Acid dichloride IV, 0.5 g, was dissolved in 0.5 ml of
dry dioxane, and the resulting solution was added to a
solution of 0.57 g of freshly distilled aniline in 12 ml
of dioxane. A fine precipitate formed and was treated
with 10% hydrogen chloride and extracted with ether.
The ethereal solution was washed with water, and the
solvent was evaporated. The solid residue was recrys-
tallized from benzene, mp 177 178 C. Found, %: C
54.26; H 6.72; B 24.77; N 6.34. C20H30B10N2O2.
Calculated, %: C 54.79; H 6.84; B 24.65; N 6.39.
HCl + H2O
I + PhMgX
VIII
Hence, it was established that dicarboxylic acid II
and some of its derivatives behave similarly to higher
dicarboxylic acids and can be used for preparing of
various C-organoderivatives of o-carborane.
EXPERIMENTAL
(o-Carborane-1,2-diyl)di(N,N-diethylpropan-
amide) (VII). A solution of 0.9 ml of diethylamine
in 5 ml of dioxane was added with stirring and cool-
ing to a soluton of 1 g of acid dichloride IV in 1.5 ml
of dry dioxane. The resulting mixture was left over-
night. The precipitate was filtered off, treated with
10% hydrogen chloride, and extracted with three
portions of ether. The ethereal solution was washed
with water, and the ether was removed. The solid
residue was recrystallized from hexane, mp 91 92 C.
Found, %: C 48.39; H 9.98; B 27.20; N 7.09.
C16H38B10N2O2. Calculated, %: C 48.24; H 9.54;
B 27.13; N 7.03.
The compounds obtained were characterized by the
IR spectra measured on a Specord-82 instrument and
by the elemental analyses.
1,2-Bis(cyanoethyl)-o-carborane was obtained by
the procedure in [2].
(o-Carborane-1,2-diyl)dipropanoic acid (II).
A mixture of 4 g of 1,2-bis(cyanoethyl)-o-carborane
and 45 ml of 75% sulfuric acid was stirred at 150
155 C for 2.5 h. The reaction mixture was cooled and
poured into an ice-cold water. The precipitate that
formed was filtered off, washed with water (3 20 ml),
and treated with 10% sodium hydroxide. The alkaline
solution was extracted with ether and acidified with
hydrochloric acid. The precipitate that formed on
standing was filtered off and dried in a water-jet-pump
vacuum to obtain 3.8 g (83%) of acid II, mp 244
(o-Carborane-1,2-diyl)di(phenyl propanoate)
(VIIIa). a. Dry benzene, 20 ml, and 1.88 g of AlCl3
were placed in a flask equipped with a funnel, a
thermometer, and a calcium chloride tube, and a solu-
tion of 2 g of acid chloride IV in 20 ml of dry
benzene was added with cooling at 20 C. The result-
ing mixture was left overnight and then poured into
an ice-cold water acidified with hydrochloric acid.
The benzene layer was separated, washed with water,
2% NaOH, and dried over potassium carbonate. The
solvent was removed, and the solid residue was
crystallized from a toluene hexane mixture to obtain
1.54 g (84%) of compound VIII, mp 135 136 C. IR
1
245 C (from toluene). IR spectrum, , cm : 1717
(C=O), 3487 (OH). Found, %: C 33.44; H 7.01; B
37.45. C8H20B10O4. Calculated, %: C 33.33; H 6.94;
B 37.45.
(o-Carborane-1,2-diyl)dipropanoyl chloride (IV)
A solution of 3.1 g of thionyl chloride in 10 ml of dry
benzene was added to 3 g of dicarboxylic acid II in
20 ml of dry benzene, and the resulting mixture was
refluxed for 2 h until HCl and SO2 no longer evolved.
Excess SOCl2 and benzene were removed in a water-
1
spectrum, , cm : 1684 (C=O); 2605, 2573 (B H).
Found, %: C 58.89; H 6.68; B 26.04. C20H28B10O2.
Calculated, %: C 58.82; H 6.86; B 26.47.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 72 No. 9 2002

SYNTHESIS OF (o-CARBORANE-1,2-DIYL)DIPROPANOIC ACID
2,4-Dinitrophenylhydrazone, mp 165 166 C.
Found, %: N 14.26. C32H36B10N8O8. Calculated, %:
N 14.58.
1385
lithium aluminum hydride in 40 ml of absolute ether.
The resulting mixture was stirred for 3 h under reflux.
After cooling, it was successively treated with 10 ml
of 50% methanol and 20 ml of 10% sulfuric acid. For
better separation of the aqueous and ethereal layers,
5 ml of hydrochloric acid was added into the separat-
ing funnel. The ethereal solution was washed with
water and dried over sodium sulfate. The solvent was
removed, and the residue was dissolved in benzene and
precipitated with hexane. The precipitate was filtered
off and washed with a 5:1 hexane benzene mixture
to obtain 1.4 g (77.7%) of compound IX. IR spectrum,
b. Compound I, 1 g, in 40 ml of absolute ether was
gradually added to ethereal C6H5MgBr (obtained from
2.5 g of Mg and 12.48 g of C6H5Br). After 1 h, a dark
precipitate formed. The mixture was stirred under
reflux for 11 h, cooled, treated with 40 ml of 20%
hydrochloric acid, cooled, and extracted with me-
thylene chloride (3 30 ml). The solvent was removed,
and the semiliquid residue was dissolved in a 9:1
heptane benzene mixture and passed through a silica
gel column which was then washed with three por-
tions of benzene. The benzene was removed in a
vacuum, and the solid tar-like residue was treated with
a small amount of acetone to form a white precipitate.
Recrystallization from a toluene hexane mixture gave
0.5 g (56%) of compound VIII, mp 135 135 C.
1
, cm : 3235 (OH); 2605, 2573 (B H). Found, %: C
36.92; H 10.03; B 40.83. C8H24B10O2. Calculated, %:
C 36.92; H 9.23; B 41.53.
REFERENCES
1. Heying, T.L., Ager, J., Clark, S.L., Alexander, R.P.,
Papetti, S., Reid, J.A., and Trotz, S.I., Inorg. Chem.,
1963, vol. 2, no. 6, pp. 1097 1100.
2,4-Dinitrophenylhydrazone, mp 165 166 C.
1,2-(3-Hydroxypropyl)-o-carborane (IX).
A suspension of 2 g of dicarboxylic acid II in 50 ml
of dry ether was added to a suspension of 3 g of
2. Kalinin, V.N., Zurlova, O.M., and Zakharkin, L.I.,
J. Organomet. Chem., 1979, vol. 166, pp. 37 38.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 72 No. 9 2002