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UDC 547.279
AZERBAIJAN CHEMICAL JOURNAL № 4 2021
ISSN 2522-1841 (Online) ISSN 0005-2531 (Print)
CYANALKYLATION OF MERCAPTOACETIC ACID ESTERS K.Z.Guseinov, *M.A.Mirzoyeva, P.A.Aliyev
Baku State University
*A.Guliyev Institute of Chemistry of Additives, NAS of Azerbaijan
Received 07.06.2021 Accepted 30.07.2021
The addition of mercaptoacetic acid esters (MAAE) to nitriles of acrylic, methacrylic, and crotonic acids easily occurs in the presence of triethylamine as a catalyst to form the corresponding 2-cyanoalkyl-alkoxycarbonylmethyl sulfides.
Keywords: esters of mercaptoacetic acid, sulfide, nitriles of acrylic-, methacrylic- and crotonic acids.
doi.org/10.32737/0005-2531-2021-4-30-34 Introduction
A number of methods for the synthesis of organosulfur compounds are known, among which synthesis based on thiols is of great importance. Having an active hydrogen atom in their molecule, thiols easily react with unsaturated compounds to form various sulfides [1- 3].
Previously, we studied the influence of organosulfur compounds obtained on the basis of various thiols on the anticorrosive properties of motor oils, and for the first time it was found that compounds containing the -SCH2COOR fragment (R - aliphatic radicals) in the molecule are much more effective than other sulfides [4].
ch2=ch-cn
Of undoubted interest are the synthesis of MAAE derivatives containing, in addition to sulfide sulfur in the molecule, the -COOR group, as well as the -CH2CH2CN group, and the study of their influence on the quality of lubricating oils. For this purpose, the reactions of various MAAE with nitriles of acrylic, meth-acrylic and crotonic acids have been studied. It was found that in the presence of triethylamine as a catalyst, the reactions of MAAE with nitriles of these acids proceed contrary to Mar-kovnikov's rule, resulting in the formation of the corresponding 2-cyanoalkylalkoxycarbonyl-methyl sulfides:
II z
o
r-o-c-ch2-s-ch2-ch2-cn o
ch2=c-cn
2 I
ch,
ch3"ch=ch-cn
(i-x)
r-o-c-ch2-s-ch2-ch-cn
° (xi-xiii) ch3
r-o-c-ch2-s-ch-ch,-cn
LI i L
o
ch,
(xiv-xvi)
r = c2h5 (i), c3h7 (ii), i-c3h7 (iii), c4h9 (iv), /-c4h9 (v), c5hu (vi), c6h13 (vii), c7h15 (viii), c8h17 (ix), (ch2)5ch (x), c2h5 (xi), /-c3h7 (xii), c4h9 (xiii), c2h5 (xiv), f-c3h7 (xv), c4h9 (xvi)
CYANALKYLATION OF MERCAPTOACETIC ACID ESTERS
31
Experimental part
To obtain 2-cyanoalkylalkoxycarbonylme-thyl sulfides (I-XVI), MAAE were used as starting products, which were synthesized by the reaction of mercaptoacetic acid with the corresponding alcohols in the presence of HCl as a catalyst, according to the method described in [5]. The IR spectra of the substances were recorded on a UR-20 device with a thin layer. The PMR spectra were recorded on a Varian T-60 spectrometer with an operating frequency of 60 MHz in a CCl4 solution, the internal standard was TMS.
General procedure for the synthesis of compounds (I-XVI). 0.005 mol of triethylamine
is added with stirring to a mixture of 0.1 mol of mercaptoacetic acid ester and 0.1 mol of un-saturated nitrile and incubated for 3 hours at 70-800C. 2-Cyanoalkylalkoxycarbonylmethyl sulfide is isolated by distillation in vacuum. The synthesized sulfides (I-XVI) are colorless liquids with a characteristic odor. They are highly soluble in organic solvents, but insoluble in water.
The physical-chemical characteristics of the synthesized sulfides are presented in Table 1.
Results and discussion
The procedure for the addition of MAAE to unsaturated acid nitriles was confirmed by an independent synthesis:
c4h9-o-c-ch2-sh+c1ch2ch2cn o
(c2h5)3n
c4h9-o-c-ch2-s-ch2-ch2-cn
o
The physical constants and spectral characteristics of 2-cyanoethylbutoxycarbonylme-thyl sulfide and the product obtained by the reaction of mercaptoacetic acid butyl ester with chloropropionic acid nitrile in the presence of an equimolar amount of triethylamine are identical. IR and NMR spectral data also confirm the structure of the synthesized compounds.
As a specific object of detailed discussion, let us consider the spectra of 2-cyano-ethylcyclohexyloxycarbonylmethyl sulfide (X).
Everything that will be said about this product applies equally to other products in this series. The IR spectra of compounds (X) (Figure 1) contain absorption bands in the fields of 2260, 1730, and 1290 cm-1, which indicates the presence of C=N, C=O, and C-O bonds, respectively [6].
In the case of the interaction of the cy-clohexyl ester of mercaptoacetic acid with acry-lonitrile, the formation of two isomeric products of the following structures is possible:
o-c-ch2-s-ch2-ch2-cn o
a
o-c-ch2-s-ch-cn
o
B
ch,
The absence of an absorption band at 1380 cm-1, characteristic of the CH3 group in the IR spectrum, indicates the formation of a product corresponding to structure A.
In the PMR spectrum of compounds (X) (Figure 2), the protons of the methylene groups
of the cyclohexyl ring are observed as a multiplet at 5=1-2.1 ppm. The proton of the methine group of the cyclohexyl ring gives a multiplet at 5=4.4-4.8 ppm. The protons of the SCH2COOR group appear as a singlet with a chemical shift of 5=3.3 ppm.
H -
-■ > i-1_L i-1_i_fc >-k
3<fO0 3Z00 Z-LOO J Soo ISOC 1400 li-oo toeo sm"1 Fig. 1. IR spectrum of 2-cyanoethylcyclohexyloxycarbonylmethyl sulfide (X).
8-7-S-$ % 3 t < 0
Fig. 2. PMR spectrum of 2-cyanoethylcyclohexyloxycarbonylmethyl sulfide (X).
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r o
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Table 1. The physical-chemical characteristics of cyanoalkylalkoxycarbonylmethyl sulfides
Compounds Yield, % B.p. (P mm merc.c.), °C d4 20 nd2 o MRd Found, % Brutto formula Calculated, %
found calc. C H N S c H N S
I 90 101-102 (0.4) 1.1290 1.4813 43.68 44.00 48.30 6.75 7.90 18.34 C7HnN02S 48.53 6.40 8.08 18.51
II 91 116-117(0.3) 1.0975 1.4790 48.39 48.62 51.54 7.11 7.30 17.25 c8h13no2s 51.31 6.99 7.48 17.12
III 88 106-107 (0.5) 1.0877 1.4742 48.40 48.62 51.10 7.18 7.22 16.91 c8h13no2s 51.31 6.99 7.48 17.12
IV 90 125-130 (0.4) 1.0744 1.4775 52.98 53.23 53.55 7.77 6.80 16.20 c9h15n02s 53.70 7.51 6.96 15.93
V 93 114-115 (0.2) 1.0679 1.4754 53.10 53.23 53.94 7.72 7.14 15.75 c9h15no2s 53.70 7.51 6.96 15.93
VI 88 136-137 (0.2) 1.0546 1.4758 57.54 57.85 55.54 8.12 6.67 15.11 CioHI7N02S 55.78 7.96 6.50 14.89
VII 92 142-143 (0.2) 1.0375 1.4751 62.23 62.47 57.42 8.58 6.27 14.18 c„h19no2s 57.60 8.35 6.11 13.98
VIII 93 154-156 (0.3) 1.0256 1.4744 66.70 67.09 59.62 8.73 5.65 13.52 c12h21no2s 59.22 8.69 5.75 13.17
IX 84 165-166 (0.4) 1.0081 1.4740 71.74 71.70 60.91 9.25 5.28 12.62 c13h23no2s 60.66 9.01 5.44 12.46
X 89 150-151 (0.2) 1.1149 1.5014 60.10 60.27 57.83 7.61 6.41 13.67 c„h17no2s 58.11 7.53 6.16 14.10
XI 70 161-162 (6) 1.1040 1.4793 48.13 48.62 51.66 7.24 7.65 17.01 c8h13no2s 51.31 6.99 7.48 17.12
XII 84 139-140 (1) 1.0677 1.4722 52.81 53.23 53.24 7.60 7.18 15.62 c9h15no2s 53.70 7.51 6.96 15.93
XIII 87 172-173 (4) 1.0457 1.4730 57.76 57.85 56.14 7.82 6.82 14.95 CIOHI7N02S 55.78 7.96 6.50 14.89
XIV 72 146-147 (2) 1.1175 1.4825 47.82 48.62 51.12 7.18 7.30 17.24 c8h13no2s 51.31 6.99 7.48 17.12
XV 85 145-146 (1.5) 1.0705 1.4764 53.07 53.23 53.42 7.82 6.71 16.18 c9h15no2s 53.70 7.51 6.96 15.93
XVI 92 169-170 (3) 1.0511 1.4758 57.76 57.85 55.32 8.16 6.74 14.76 CIOHI7N02S 55.78 7.96 6.50 14.89
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In the PMR spectrum of compounds (X) (Figure 2), the protons of the methylene groups of the cyclohexyl ring are observed as a multiplet at 5=1-2.1 ppm. The proton of the methine group of the cyclohexyl ring gives a multiplet at 5=4.4-4.8 ppm. The protons of the SCH2COOR group appear as a singlet with a chemical shift of 5=3.3 ppm.
The resonances of the signals of the protons of two methylene groups of the N=C-CH2-CH2-S fragment appear as triplets with chemical shifts 5а=2.75 and 5b=2.9 ppm. The absence of resonance signals of protons from the methyl and methine groups of the N=C-CH2-CH2-S fragment, which would have occurred during the formation of a product corresponding to structure B, also confirms the structure of the synthesized compounds [7].
Thus, the MAAE cyanalkylation method has been used to synthesize oxygen-, sulfur- and
nitrogen-containing organic compounds that are of interest as potential additives to lubricating oils.
References
1. Sintez sulfidov, tiofenov i tiolov. Otv. red. Karau-lova E.N. M.: Nauka, 1988. 208 s.
2. Khimiya organicheskikh soyedineniy sery. Pod. red. L.I.Belenkogo. M.: Khimiy, 1988. 320 s.
3. Sardarova S.A., Osmanova S.F., Mamedov F.A., Qamidova Sh.Y. Sintez i issledovaniye slojnikh efi-rov 1, 1 -Ä/'s-(hidroksikarbonilmetiltio)-1 -ariletanov. Khimicheskie Problemi 2015. No 3. C. 319-322.
4. Guseinov K.Z. Funktsionalniye proizvodniye tiolov i fenolov v kachestve prisadok k smazochnym maslam i toplivam. Dis. .. .dokt. khim. nauk. Baku: In-t Khimii Prisadok AN Azerb.SSR, 1991. 471 s.
5. Guseinov K.Z., Gambarov D.G., Mirzoeva M.A., Mamedov F.N., Fati-zade R.F. Sintez efirov tiogli-kolevoy kisloty i primeneniye ikh v analiticheskoy khimii. Azerb. khim. jurn. 1977. № 6. S. 103-107.
6. Nakanisi K. Infrakrasniye spektry i stroyeniye organicheskikh soyedineniy. M.: Mir, 1965. 216 s.
7. Ionin B.I., Yershov B.A., Koltsov A.I. YAMR spek-troskopiya v organicheskoy khimii. L.: Khimiya, 1983. 269 s.
MERKAPTOSÍRKO TUR§USU EFÍRLORINÍN SÍANALKILLO^MOSÍ
Q.Z.Hüseynov, M.O.Mirzayeva, Р.Э.ЭИуеу
Trietilaminin katalizator kimi i§tiraki ila merkaptosirka tur§usaunun efirlari akril-, metakril- va kroton tur§ulannin nitrillari ila asan birla§ma reaksiyasina daxul olurlar. Birla§ma reaksiyasi Markovnikov qaydasinin aksina gedir va naticada müvafiq 2-sianalkilalkoksikarbonilmetilsulfidlar amala galir.
Agar sozlar: merkaptosirka tur§usunun efirlari, sulfid, akril-, metakril- v3 kroton tur§ularmm nitrillari.
ЦИАНАЛКИЛИРОВАНИЕ ЭФИРОВ МЕРКАПТОУКСУСНОЙ КИСЛОТЫ
К.З.Гусейнов, М.А.Мирзоева, П.А.Алиев
Присоединение эфиров меркаптоуксусной кислоты (ЭМУК) к нитрилам акрил-, метакрил- и кротоновой кислот легко происходит в присутствии триэтиламина в качестве катализатора с образованием соответствующих 2-цианоалкилалкоксикарбонилметилсульфидов.
Ключевые слова: эфиры меркаптоуксусной кислоты, сульфид, нитрилы акрил-, метакрил- и кротоновой кислот.
