Synthesis of 2-[2-(2-Thiocyanato-3-arylpropionyloxy)ethoxy]ethyl Acrylates
499
TABLE 1. Yields and Physicochemical Characteristics of 2-[2-(2-Thiocyanato-3-arylpropionyloxy)ethoxy]ethyl Acrylates (I – IV)
20
D
20
4
Com-
pound
n
d
R
Yield, %
59
Empirical formula
C17H19NO5S
1H NMR spectrum: d, ppm (J, Hz)
I
H
1.5052 1.1580
1.5136 1.1598
1.5124 1.1608
1.5128 1.1588
7.30 – 7.20 (m, 5H, Ph), 6.30 (dd, JHH 10 Hz, H-cis, =CH2), 6.14 (dd, JHH 10 Hz,
1H, =CH–), 5.93 (dd, JHH 15 Hz, H-trans, =CH2), 4.50 – 4.44 (m, 1H, CH), 4.20
(t, 4H, 2(–OCH2)), 3.48 (dd, JHH 2 Hz, 4H, –CH2–O–CH2), 3.33 (dd, JHH
7 Hz), 3.10 (dd, JHH 7 Hz, 2H, CH2Ph).
II
o-CH3
m-CH3
p-CH3
35
42
47
C18H21NO5S
C18H21NO5S
C18H21NO5S
7.22 – 7.10 (m, 4H, C6H4), 6.32 (dd, JHH 10 Hz, H-cis, =CH2), 6.15 (dd, JHH
10 Hz, 1H, =CH–), 5.94 (dd, JHH 15 Hz, H-trans, =CH2), 4.51 – 4.45 (m, 1H,
CH), 4.22 (t, 4H, 2(–OCH2)), 3.46 (dd, JHH 2 Hz, 4H, –CH2–O–CH2), 3.32 (dd,
JHH 7 Hz), 3.09 (dd, JHH 7 Hz, 2H, CH2–C6H4), 2.25 (s, 3H, o-CH3–C6H4).
III
IV
7.34 – 7.16 (m, 4H, C6H4), 6.34 (dd, JHH 10 Hz, H-cis, =CH2), 6.15 (dd, JHH
10 Hz, 1H, =CH–), 5.94 (dd, JHH 15 Hz, H-trans, =CH2), 4.50 – 4.44 (m, 1H,
CH), 4.24 (t, 4H, 2(–OCH2)), 3.45 (dd, JHH 2 Hz, 4H, –CH2–O–CH2), 3.31 (dd,
JHH 7 Hz), 3.10 (dd, JHH 7 Hz, 2H, CH2–C6H4), 2.31 (s, 3H, m-CH3–C6H4).
7.24 – 7.08 (m, 4H, C6H4), 6.32 (dd, JHH 10 Hz, H-cis, =CH2), 6.16 (dd, JHH
10 Hz, 1H, =CH–), 5.92 (dd, JHH 15 Hz, H-trans, =CH2), 4.50 – 4.44 (m, 1H,
CH), 4.23 (t, 4H, 2(–OCH2)), 3.46 (dd, JHH 2 Hz, 4H, –CH2–O–CH2), 3.33 (dd,
JHH 7 Hz), 3.12 (dd, JHH 7 Hz, 2H, CH2–C6H4), 2.37 (s, 3H, p–CH3–C6H4).
EXPERIMENTAL CHEMICAL PART
EXPERIMENTAL BIOLOGICAL PART
The IR spectra of compounds I – II were recorded on the
IKS-29 (Russia) and Specord M80 (Germany) spectrophoto-
The antimicrobial activity of the synthesized compounds
I – IV was determined by the conventional method of double
serial dilutions in a meat-infusion broth (pH 7.2 – 7.4). The
initial dilution was prepared by dissolving 10 mg of a test
substance in 1 ml of ethanol, followed by adding 9 ml of dis-
tilled water. The test objects were represented by standard
strains of Gram-positive (Staphylococcus aureus ATCC
209), spore-forming (Bacillus cereus ATCC 10702), and
Gram-negative (Escherichia coli ATCC O55K-59, Pseudo-
monas aeruginosa 103) bacteria.
Double serial dilutions of the stock solutions in 2 ml of
the nutrient medium were prepared immediately before the
test. Then 0.2 ml of a bacterial suspension (with a load of 105
bacterial cells per ml) of the test microbe species was intro-
duced into test tubes and the samples were incubated at 37°C
for 18 – 24 h, after which the microbial growth was visually
1
meters using samples prepared as thin films. The H NMR
spectra were measured with a Varian Gemini spectrometer
(working frequency, 300 MHz) using DMSO-d6 as the sol-
vent and HMDS as the internal standard. Purity of the synt-
hesized compounds was checked by TLC on Silufol UV-254
plates eluted with a hexane – chloroform – diethyl ether
(7 : 5 : 2) mixture. The data of elemental analyses (N, S) coin-
cided with the results of analytical calculations using the em-
pirical formulas.
2-[2-(2-Thiocyanato-3-phenylpropionyloxy)ethoxy]-
ethyl acrylate (I). To a mixture of 0.10 mole 2-(2-acryloylo-
xyethoxy)ethyl acrylate, 0.01 mole copper(II) tetrafluorobo-
rate, and 0.14 mole of ammonium rhodanide in 200 ml of a
water – acetone mixture (1 : 2) cooled to – 5 to 0°C was gra-
dually (over 75 min) added 0.12 mole of phenyldiazonium
tetrafluoroborate. At this temperature, the evolution of nitro-
gen continued for ~2 h. When the gas evolution ceased, the
mixture was treated with 250 ml of diethyl ether. The extract
was washed with water and dried over anhydrous magnesi-
um sulfate. Then the solvent was evaporated and the residue
was chromatographed on an Al2O3 column eluted with a he-
xane – chloroform – diethyl ether (7 : 5 : 2) mixture to obtain
20.7 g of the target compound I; IR spectrum (nmax, cm – 1):
TABLE 2. Antimicrobial Activity (Minimum Bacteriostatic and
Bactericidal Concentrations, mg/ml) of 2-[2-(2-Thiocyanato-3-aryl-
propionyloxy)ethoxy]ethyl Acrylates (I – IV)
Test culture
B. cereus E. coli
MBsC MBcC MBsC MBcC MBsC MBcC MBsC MBcC
Com-
pound
S. aureus
P. aeruginosa
I
500
NA
NA
500
250
NA
NA
NA
NA
NA
500
500
NA
NA
500
NA
NA
NA
II
62.5 62.5
31.5 62.5
62.5 125
2156 (SCN), 1636 (CH=CH2), 1724 (C=O); C17H19NO5S.
Compounds II – IV were obtained using analogous pro-
III
IV
250
500
500
500
62.5 125
500
NA
cedures with the corresponding aryldiazonium tetrafluorobo-
rates (Table 1).
Note: NA = not assessed.