Mono- and diesters of N-benzoylaminoacetic acid as antiwear additives to synthetic oils

Article abstract of DOI:10.1134/S107042721104032X

Mono- and diesters of N-benzoylaminoacetic acid, which exhibit high wear-preventive properties in a synthetic ester oil, were synthesized.

Full text of DOI:10.1134/S107042721104032X

ISSN 1070-4272, Russian Journal of Applied Chemistry, 2011, Vol. 84, No. 4, pp. 732−734. © Pleiades Publishing, Ltd., 2011.
Original Russian Text © A.A. Makhmudova, N.S. Kyazimova, V.S. Gasanov, R.S. Mamedova, 2011, published in Zhurnal Prikladnoi Khimii, 2011, Vol. 84,
No. 4, pp. 697−699.
BRIEF
COMMUNICATIONS
Mono- and Diesters of N-Benzoylaminoacetic
Acid as Antiwear Additives to Synthetic Oils
A. A. Makhmudova, N. S. Kyazimova, V. S. Gasanov, and R. S. Mamedova
Azerbaijan State Pedagogical University, Baku, Azerbaijan
A.M. Kuliev Institute of Chemistry of Additives, National Academy of Azerbaijan, Baku, Azerbaijan
Received July 6, 2010
Abstract—Mono- and diesters of N-benzoylaminoacetic acid, which exhibit high wear-preventive properties in
a synthetic ester oil, were synthesized.
DOI: 10.1134/S107042721104032X
In connection with development of synthetic high-
temperature oils the need for antiwear additives efficient
at high temperatures has increased for last years. Devel-
opment of such additives is caused by the necessity to
exclude from oils traditional additives containing reactive
elements, sulfur, phosphorus, and halogens, causing cor-
rosion of metal surfaces and formation of deposit at high
temperatures [1, 2]. In this connection a necessity arises
for the replacement of such additives by compounds,
which do not enter into chemical reactions with a metal
surface, but capable to form strong adsorption films [3].
stability to thermal decomposition and oxidation at high
temperatures [4, 5].
These compounds were obtained by the esterification
reaction of N-benzoylaminoacetic acid with dihydric
alcohols in the presence of the KU-2 catalyst according
to the scheme
The structure of the synthesized compounds was
confirmed by IR spectroscopy data. Absorption bands
characteristic of the carboxyl group COOH (960 cm–1)
are absent from the IR spectra of the synthesized mono-
and diesters of N-benzoylaminoacetic acid. The physi-
cochemical properties of the synthesized compounds are
shown in Table 1.
The present work is devoted to the synthesis of mono-
and diesters of N-benzoylaminoacetic acid and to the
study of their influence on the wear-preventive proper-
ties of ester oils. The expediency of creating antiwear
additives on the basis of these compounds is defined
by their high adsorption capacity in combination with
Wear-preventive properties of compounds were
estimated on a four-ball-type friction machine (FBM)
according to GOST 9490-75 by the fixed-load method in
the temperature interval of 20–200°С at a spindle speed
of 1500 rpm, a trial duration of 1 h, and a load of 20 kgf
(balls of ShKh-15 steel, diameter of 12.7 mm). The ester
of pentaerythrite and С5–С9 synthetic fatty acids (PEE)
was used as a synthetic oil. A sample of the oil with
a known additive, tricresyl phosphate (CH3C6H4O)3PO
(TCP), was tested for comparison. Test data are presented
in Table 2.
nC6H5CONHCH2COOH + HOROH
n = 1
C6H5CONHCH2COOROH
_H2O
I_III
n = 2
(C6H5CONHCH2COO)2R'
_2H2O
IV_VI
It is seen from Table 2 that the compounds under
study noticeably raise wear-preventive properties of the
pentaerythrite ester, the wear reduction to the values di =
R = (CH2)3 (I), (CH2)4 (II), (CH2)2O(CH2)2 (III); R' =
(CH2)3 (IV), (CH2)4 (V), and (CH2)2O(CH2)2 (VI).
732

MONO- AND DIESTERS OF N-BENZOYLAMINOACETIC ACID
Table 1. Characteristic of mono- and diesters of N-benzoylaminoacetic acid
733
Found, %
Calculated, %
Compound
Yield, %
mp, °С
Gross-formula
C
H
N
I
72
70
142–143
155–158
60.64
60.75
6.28
6.33
5.80
5.90
C12H15NO4
C13H17NO4
II
62.21
62.15
6.71
6.77
5.63
5.5
III
IV
V
70
64
66
65
38
138
147
31
58.50
58.43
6.48
6.37
5.22
5.24
C13H17NO5
C21H22N2O6
C22H24N2O6
C22H24N2O7
63.41
63.2
5.45
5.53
7.1
7.0
64.15
64.08
5.9
5.83
6.9
6.8
VI
63.80
63.77
5.75
5.80
3.42
3.38
Table 2. Effect of mono- and diesters of N-benzoylaminoacetic acid on wear-preventive properties of pentaerythrite ester
Wear scar diameter di, mm
Compound
Concentration, %
1 h
4 h
PEE without additive
Tricresyl phosphate
–
0.90
0.95
1
3
4
0.80
0.70
0.55
0.75
0.70
0.50
C6H5CONHCH2COO(CH2)3OH (I)
1
2
0.65
0.60
0.70
0.65
C6H5CONHCH2COO(CH2)4OH (II)
C6H5CONHCH2COO(CH2)2O(CH2)2OH (III)
(C6H5CONHCH2COO)2(CH2)3 (IV)
(C6H5CONHCH2COO)2(CH2)4 (V)
1
2
0.70
0.55
0.75
0.60
1
2
0.60
0.50
0.55
0.50
0.5
1
0.60
0.55
0.60
0.50
0.5
1
0.55
0.45
0.60
0.50
(C6H5CONHCH2COO)2(CH2)2O(CH2)2 (VI)
1
2
0.55
0.45
0.50
0.40
0.5–0.55 in the presence of the compounds under study
being reached at lower concentrations than for tricresyl
phosphate (compounds I, IV, and V).
increasing number of methylene groups and molecular
weight of the esters.
High wear-preventive properties of the studied com-
pounds are probably caused by the presence of –COOR,
–N<, and –C=O groups characterized by intensive adsorp-
The lubricity effectiveness of esters increases in the
presence of hydroxyl groups in molecules, and also with
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 84 No. 4 2011

734
MAKHMUDOVA et al.
tion on metal surfaces. In this case charged boundary lay-
ers bound with the metal basically by physical adsorption
forces are formed on the metal surface.
obtained similarly.
The IR spectra of the specified compounds were taken
on a Specord 75-IR instrument.
Thus, the possibility in principle of creating antiwear
additives to pentaerythrite ester on the basis of compounds
belonging to the mono- and diesters of N-benzo-
ylaminoacetic acid has been established.
CONCLUSIONS
(1) Mono- and diesters of N-benzoylaminoacetic acid
were synthesized by reactions of this acid with dihydric
alcohols.
EXPERIMENTAL
(2) Wear-preventive properties of the synthesized
compounds in the temperature range of 20–200°С were
determined.
3-Hydroxypropyl ester of benzoylaminoacetic acid.
To a solution of N-benzoylaminoacetic acid (8.95 g,
0.05 mol) in 50 ml of dehydrated toluene propanediol-1,3
(7.6 g, 0.05 mol) and KU-2 cation-exchange resin (2.4 g)
were added. The mixture was heated up at 105°С within
5 h with stirring. Water in the form of azeotrope was col-
lected in a Dyne–Stark trap. After termination of water
evolution the reaction product was filtrated, the solvent
was distilled off, and the residual was recrystallized
from isopropanol. White crystals with melting point of
148–150°С were obtained. Yield 72%. Other monoesters
of this series were obtained similarly.
(3) It was found that the lubricity effectiveness of
esters increases in the presence of hydroxyl groups as the
number of methylene groups and the molecular weight
of the esters increase.
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