Methoxycarbonylation of Alkyl-, Cycloalkyl-, and Arylamines with Dimethyl Carbonate in the Presence of Binder-Free Zeolite

Article abstract of DOI:10.1134/S1070428020070179

Abstract: Methyl N-alkyl-, N-cycloalkyl-, and N-arylcarbamates were synthesized by reaction of the correspondingamines with dimethyl carbonate in the presence of binder-free FeHY zeolite. Theoptimal conditions (reactant ratio, amount of the catalyst, temperature,reaction time) were found to afford the target products with high yields.

Full text of DOI:10.1134/S1070428020070179

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2020, Vol. 56, No. 7, pp. 1228–1235. © Pleiades Publishing, Ltd., 2020.
Russian Text © The Author(s), 2020, published in Zhurnal Organicheskoi Khimii, 2020, Vol. 56, No. 7, pp. 1123–1131.
Methoxycarbonylation of Alkyl-, Cycloalkyl-, and Arylamines
with Dimethyl Carbonate in the Presence
of Binder-Free Zeolite
a,
a
a
a
R. I. Khusnutdinov *, N. A. Shchadneva , Yu. Yu. Mayakova , and A. N. Khazipova
a
Institute of Petrochemistry and Catalysis, Russian Academy of Sciences, Ufa, 450075 Russia
*
e-mail: inklab4@gmail.com
Received February 27, 2020; revised April 18, 2020; accepted April 19, 2020
Abstract—Methyl N-alkyl-, N-cycloalkyl-, and N-arylcarbamates were synthesized by reaction of the corre-
sponding amines with dimethyl carbonate in the presence of binder-free FeHY zeolite. The optimal conditions
(reactant ratio, amount of the catalyst, temperature, reaction time) were found to afford the target products with
high yields.
Keywords: dimethyl carbonate, N-alkylcarbamates, N-cycloalkylcarbamates, N-arylcarbamates, zeolite catalyst
DOI: 10.1134/S1070428020070179
N-Substituted carbamates are starting materials in
phosgene-free syntheses of isocyanates that are widely
used for the preparation of pesticides, fungicides, her-
bicides, medicines, cosmetics, as well as polyurethanes;
they are also used as protecting groups in organic
synthesis. Carbamates are of great interest as com-
pounds exhibiting various biological activities, in
particular anesthetics [1], anticholinesterase agents [2],
preservatives [3], and insecticides [4]. Bi- and poly-
functional urethanes are widely used in the manufacture
of construction materials, heat insulators, heavy duty
revetments with specified properties, durable sealants,
and adhesives [5].
Pb(NO ) catalyzed methoxycarbonylation of propyl-,
3 2
butyl-, and hexylamines at 100°C (2 h). In a number of
studies, primary amines were subjected to methoxycar-
bonylation with dimethyl carbonate in the presence of
heterogeneous catalysts such as ZrO /SiO (25 wt %)
2
2
[9], La O /SiO [10], and γ-Al O [11]. These reactions
2
3
2
2
3
required elevated temperature (150–170°C) and pro-
longed time (7–48 h). Sarmah and Srivastava [12]
proposed a modified zeolite, meso-ZSM-5 containing
30% of MnO , to catalyze the reaction of benzylamine
2
with dimethyl carbonate. The reaction was complete in
24 h at 80°C, and the yield of methyl benzylcarbamate
was 64%. N-Benzylidenebenzylamine was also formed
as by-product (yield 16%).
Organic carbamates can be obtained by various
methods. In particular, they are prepared by reaction of
aliphatic or aromatic amines with dimethyl carbonate
The goal of the present work was to develop a new
general method for methoxycarbonylation of amines
with dimethyl carbonate in the presence of micro-,
macro-, and mesoporous zeolites. Preliminarily, the
following zeolites were tested as catalysts in methoxy-
carbonylation of amines: NaX, Y, HY, and FeHY-
mmm. No appreciable catalytic activity was demon-
strated by NaX, Y, and HY zeolites. The iron-con-
taining zeolite FeHY-mmm proved to be an efficient
catalyst in the methoxycarbonylation of alkyl-, cyclo-
alkyl-, and arylamines with dimethyl carbonate. It was
prepared by impregnating binder-free micro-, macro-,
and mesoporous HY-mmm zeolite with a solution of
Fe(NO ) ·9H O, followed by thermal treatment at
(40 equiv) in the presence of a base such as potassium
tert-butoxide and sodium methoxide (1.2 equiv) [6].
Methoxycarbonylation of amines in solution can be
catalyzed by transition metal compounds, e.g.,
Mn(OAc) , Co(OAc) , and Cr(OAc) . For example, the
2
2
3
reaction of hexane-1,6-diamine with 4 equiv of di-
methyl carbonate at 90°C (5 h) in the presence of
Mn(OAc) (7 wt %) afforded 98% of dimethyl
2
N,N′-(hexane-1,6-diyl)dicarbamate [7]. However, the
use of homogeneous catalysts has drawbacks related to
the necessity of isolation of waste catalyst and impos-
sibility of its repeated use. According to Baba et al. [8],
3
3
2
1
228

METHOXYCARBONYLATION OF ALKYL-, CYCLOALKYL-, AND ARYLAMINES
Table 1. Reaction of butan-1-amine (1a) with dimethyl carbonate
1229
Yield, %
Temperature, °C
Reaction time, h
1
b
1c
0
9
0
1
1
1
2
25
52
95
49
1
1
1
00
20
20
0
0
49
1
50°C for 4 h and at 450°C for 3 h. We thus obtained
93% yield, whereas after 2 h a mixture of compound
2b and methyl N-heptyl-N-methylcarbamate (2c) at
a ratio of 1:1 was formed (Scheme 2). Thus, the length
of the alkyl chain in the initial amine almost does not
affect the yield and selectivity.
samples of FeHY-mmm containing 3–5 wt % of
Fe O [13, 14].
2
3
The yields of N-substituted carbamates in the reac-
tion of amines with dimethyl carbonate catalyzed by
FeHY-mmm depended on the initial amine, amount of
the catalyst, and reaction conditions. The conditions
were optimized (Table 1) using the reaction of butan-1-
amine (1a) with dimethyl carbonate in the presence of
Cycloropanamine (3a) reacted with dimethyl car-
bonate under similar conditions (120°C, 30 min,
3 wt % FeHY-mmm) to produce a mixture of methyl
N-cyclopropylcarbamate (3b) and methyl N-cyclo-
propyl-N-methylcarbamate (3c) at a ratio of 1:9, the
conversion of 3a being complete. Further increase of
the reaction time was undesirable due to opening of the
cyclopropane ring and formation of high-molecular-
weight compounds (Scheme 3).
3
wt % of FeHY-mmm. It was found that the reaction
at 120°C in 1 h produces 95% of methyl N-butylcar-
bamate 1b. Prolonged reaction (2 h) led to the forma-
tion of 49% of methyl N-butyl-N-methylcarbamate (1c)
as a result of methylation of 1b. Dimethyl carbonate
was taken in excess (4 equiv) since it acted simul-
taneously as reagent and solvent (Scheme 1).
The reactions of cyclopentanamine (4a), cyclohex-
anamine (5a), cycloheptaneamine (6a), and cyclooc-
tanamine (7a) with dimethyl carbonate at 120°C (1 h)
gave 70–80% of the corresponding methyl N-cycloal-
kylcarbamates 4b–7b, regardless of the ring size. When
Analogous reaction of heptan-1-amine (2a) with
dimethyl carbonate in the presence of FeHY-mmm at
1
20°C (1 h) gave methyl N-heptylcarbamate (2b) in
Scheme 1.
O
1
h
Bu
MeO
N
H
9
9
5%
O
FeHY-mmm (3 wt %), 120°C
1
b
BuNH2
+
MeO
OMe
O
2
h
1
a
1:4
1
b
+
Bu
MeO
N
8%
Me
1
:1
1c
Scheme 2.
O
1
h
C H
7
15
MeO
N
H
9
3%
O
FeHY-mmm (3 wt %), 120°C
2
b
C H15NH2
7
+
MeO
OMe
O
2
h
2
a
1:4
2
b
+
C H
7 15
MeO
N
9
7%
Me
2c
1
:1
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 56 No. 7 2020

1230
KHUSNUTDINOV et al.
Scheme 3.
FeHY-mmm (3 wt %)
20°C, 30 min
O
O
O
1
NH2
+
+
9
8%
MeO
N
H
MeO
N
MeO
OMe
Me
3
a
1:4
3
b
1:9
3c
Scheme 4.
O
1
h
(
)n
MeO
N
H
2
0%
O
FeHY-mmm (3 wt %), 120°C
4
b–7b
+
NH2
a–7a
O
(
)n
MeO
OMe
2
h
4
1:4
( )
n
4
b–7b
+
MeO
N
8
5%
Me
4
c–7c
1
:1
n = 1–4.
Scheme 5.
FeHY-mmm (3 wt %)
20°C, 1 h
O
O
1
+
9
3%
MeO
N
H
NH2
MeO
OMe
8
a
1:4
8b
Scheme 6.
NH2
FeHY-mmm (3 wt %)
O
O
1
20°C, 1 h
+
MeO
N
H
MeO
OMe
Me
Me
1
0a–12a
10b–12b
1
0, o-Me, 27%; 11, m-Me, 45%; 12, p-Me, 88%.
the reaction time was prolonged to 2 h, mixtures of
approximately equal amounts of 4b–7b and their
N-methyl derivatives 4c–7c were formed. Further
increase of the reaction time to 5 h did not increase the
yield of 4c–7c but favored methylation of initial amines
120°C (1 h) afforded 85% of methyl N-phenylcar-
bamate (9b). In the case of isomeric toluidines
10a–12a, the position of the methyl group with respect
to amino significantly influenced the yield of carba-
mates 10b–12b. The highest yield was obtained for
p-toluidine (12a). Raising the temperature or increasing
the reaction time changed the reaction direction toward
formation of the corresponding N-methylanilines
4
a–7a (Scheme 4).
Despite the presence of a bulky substituent, ada-
mantan-1-amine (8a) actively reacted with dimethyl
carbonate under similar conditions, yielding methyl
N-(adamantan-1-yl)carbamate (8b) as the only product
(Scheme 6) [15].
Other para-substituted anilines, 4-chloroaniline
13a), 4-bromoaniline (14a), and 4-nitroaniline (15a),
(93%, Scheme 5). No further methylation of 8b at the
(
nitrogen atom was observed when the reaction time
was prolonged or the amount of the catalyst was in-
creased to 5 wt %, presumably due to steric effect of
the bulky adamantane fragment.
also smoothly reacted with dimethyl carbonate under
the given conditions to produce methyl N-(4-chloro-
phenyl)carbamate (13b), methyl N-(4-bromophenyl)-
carbamate (14b), and methyl N-(4-nitrophenyl)car-
bamate (15b), respectively, in 85–88% yields
(Scheme 7). No further methylation of 13b–15b was
Methoxycarbonylation of aniline (9a) with dimethyl
carbonate in the presence of 5 wt % FeHY-mmm at
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 56 No. 7 2020

METHOXYCARBONYLATION OF ALKYL-, CYCLOALKYL-, AND ARYLAMINES
1231
Scheme 7.
R
R
FeHY-mmm
NH2
O
O
O
1
20°C, 1 h
+
+
MeO
N
H
MeO
N
MeO
OMe
R
Me
9
a, 13a–15a
9b, 13b–15b
9c, 13c–15c
traces)
(
9
, R = H; 13, R = Cl; 14, R = Br; 15, R = NO2.
Scheme 8.
FeHY-mmm (5 wt %)
O
O
1
20°C, 1 h
Ph
NH2
+
9
8%
MeO
N
H
Ph
MeO
OMe
1
6a
16b
Scheme 9.
O
FeHY-mmm (5 wt %)
20°C, 6 h
O
1
1
6a
+
16b
+
+
MeO
N
Ph
Ph
N
Ph
9
8%
MeO
OMe
Me
16c, 51%
2
5%
16d, 24%
Scheme 10.
FeHY-mmm (3 wt %)
20°C, 1 h
O
Bu
Me
1
N
Bu NH
+
2
9
9%
MeO
1:4
OMe
Bu
1
7a
17b
observed when the reaction time was prolonged, but
EXPERIMENTAL
the corresponding N-methylanilines RC H NHMe
were formed.
6
4
Initial reactants of pure and chemically pure grades
were commercial products (Sigma–Aldrich). The
Methoxycarbonylation of benzylamine (16a) with
dimethylcarbonate in the presence of 5 wt % FeHY-
mmm at 120°C (1 h) quantitatively afforded methyl
N-benzylcarbamate (16b) (Scheme 8). After 6 h, a mix-
ture of 16b, methyl N-benzyl-N-methylcarbamate
1
3
C NMR spectra were recorded on a Bruker Avance
00 spectrometer (Germany) at 100.62 MHz using
4
CDCl as solvent (unless otherwise stated). The mass
3
spectra (electron impact, 70 eV) were obtained with
a Shimadzu GCMS-QP2010Plus instrument (Japan)
equipped with an SPB-5 capillary column, 30 m×
(16c), and N-benzylidenebenzylamine (16d) at a ratio
of 1:2:1 was obtained (Scheme 9).
0
.25 mm; carrier gas helium; oven temperature
Secondary amines, in particular dibutylamine (17a),
reacted with dimethyl carbonate in the presence of
FeHY-mmm to give only the corresponding tertiary
amine, N-butyl-N-methylbutan-1-amine (17b)
programming from 40 to 300°C at a rate of 8 deg/min,
injector temperature 280°C. The IR spectra were
recorded in KBr or mineral oil on a Bruker-Vertex 79V
spectrometer (Germany). The elemental compositions
were determined using a Carlo Erba 1106 elemental
analyzer (Italy).
(Scheme 10).
Thus, we have developed a method for the synthesis
of methyl N-alkyl-, N-cycloalkyl-, and N-arylcarba-
mates in high yields by methoxycarbonylation of the
corresponding primary amines with dimethyl carbonate
in the presence of binder-free FeHY-mmm zeolite
catalyst.
The progress of reactions and the purity of the
isolated compounds were monitored by GLC with
a Shimadzu GC-9A or GC-2014 chromatograph
(Japan) using a 2-m×3-mm column packed with SE-30
(5%) on Chromaton N-AW-HMDS; oven temperature
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 56 No. 7 2020

1232
KHUSNUTDINOV et al.
programming from 50 to 270°C at a rate of 8 deg/min;
carrier gas helium, flow rate 47 mL/min.
Methyl N-cyclopropylcarbamate (3b). Yield
1.036 g (90%), colorless oil, bp 84–85°C (11 mm Hg);
published data [16]: bp 95–96°C (12 mm Hg).
The binder-free zeolite catalyst (FeHY-mmm) was
prepared as described in [13, 14].
1
3
1
2
C NMR spectrum, δ , ppm: 6.68 (C ), 22.89 (C ),
C
4
3
5
1.95 (C ), 158.47 (C ). Found, %: C 51.85; H 7.45;
General procedure for the methoxycarbonylation
of alkyl-, cycloalkyl-, and arylamines with dimethyl
carbonate. The reactions were carried out in a 17-mL
stainless steel high-pressure micro reactor or a 20-mL
glass ampule. The results of parallel runs were almost
the same. The reactor (ampule) was charged with
N 11.92. C H NO . Calculated, %: C 52.116; H 7.88;
5
9
2
N 12.17. M 115.130.
Methyl N-cyclopropyl-N-methylcarbamate (3c).
Yield 0.129 g (10%), colorless oil, bp 84–85°C
–
1
(
1
11 mm Hg). IR spectrum, ν, cm : 1028 m, 1040 m,
13
159 s, 1287 s, 1363 m, 1375 m, 1695 s, 2984 s, br. C
NMR spectrum, δ , ppm: 7.68 (C , C ), 30.52 (C ),
3
–5 wt % of FeHY-mmm, 10 mmol of the correspond-
2
3
1
C
ing amine, and 40 mmol of dimethyl carbonate. The
reactor was hermetically closed (the ampule was
sealed) and heated at 120°C for 0.5–2 h. When the
reaction was complete, the reactor (ampule) was cooled
to room temperature and opened, the mixture was
filtered through a layer of alumina, excess dimethyl
carbonate was distilled off, and the residue was dis-
tilled under atmospheric or reduced pressure or crys-
tallized from ethanol.
3
4.80 (CH ), 52.07 (OCH ), 158.47 (C=O). Mass
3 3
+
spectrum, m/z (I , %): 129 (60) [M] , 115 (80), 100
rel
(100), 84 (40), 70 (90), 59 (92), 40 (95). Found, %:
C 54.97; H 7.99; N 8.22. C H NO . Calculated, %:
6
11
2
C 55.80; H 8.58; N 10.84. M 129.157.
Methyl N-cyclopentylcarbamate (4b). Yield
1
3
1
.39 g (97%), bp 72–73°C (2 mm Hg). C NMR
3
4
2
5
spectrum, δ , ppm: 23.52 d (C , C ), 33.39 d (C , C ),
1.80 (C ), 52.75 (OCH ), 156.60 (C=O), 42.32.
C
1
5
3
Methyl N-butylcarbamate (1b). Yield 1.246 g
Found, %: C 57.95; H 8.29; N 9.66. C H NO .
7
13
2
1
3
(
95%), bp 82–83°C (9 mm Hg). C NMR spectrum,
Calculated, %: C 58.72; H 9.15; N 9.78. M 143.183.
3
2
δ , ppm: 13.68 (CH ), 20.01 (C ), 31.93 (C ), 40.65
C
3
Methyl N-cyclopentyl-N-methylcarbamate (4c).
1
(
C ), 51.70 (OCH ), 157.67 (C=O). Mass spectrum,
m/z (I , %): 131 (3) [M] , 117 (1), 103 (15), 90 (5), 77
3
Yield 0.628 g (40%), bp 80–81°C (8 mm Hg).
+
rel
13
3
4
C NMR spectrum, δ , ppm: 23.58 d (C , C ), 28.59
C
(56), 70 (100), 55 (85), 41 (57), 29 (35). Found, %:
2
5
1
(CH ), 33.18 d (C , C ), 56.65 (C ), 51.96 (OCH ),
3
3
C 54.37; H 9.49; N 10.22. C H NO . Calculated, %:
6
13
2
1
56.46 (C=O). Found, %: C 59.95; H 9.29; N 8.66.
C 54.94; H 9.99; N 10.68. M 131.172.
C H NO . Calculated, %: C 61.12; H 9.62; N 8.91.
8
15
2
Methyl N-butyl-N-methylcarbamate (1c). Yield
M 157.210.
Methyl N-cyclohexylcarbamate (5b). Yield
.446 g (92%), mp 74–75.0°C (from cyclohexane);
published data [17]: mp 74–74.5°C. IR spectrum
1
3
0
.711 g (49%), bp 70–71°C (20 mm Hg). C NMR
3
spectrum, δ , ppm: 13.57 (CH ), 19.81 (C ), 30.47
C ), 49.65 (C ), 52.17 (OCH ), 157.17 (C=O).
C
3
1
2
1
(
3
Found, %: C 56.95; H 10.17; N 9.12. C H NO . Cal-
–1
7
15
2
(
KBr), ν, cm : 778 m, 894 m, 1052 s, br, 1238 s,
culated, %: C 57.90; H 10.41; N 9.65. M 145.199.
1
250 s, 1284 s, 1350 s, 1451 s, 1533 s, 1695 s, 3320 m,
1
3
3
5
Methyl N-heptylcarbamate (2b). Yield 1.611 g
3350 s. C NMR spectrum, δ , ppm: 24.85 (C , C ),
25.48 (C ), 33.59 (C , C ), 49.82 (C ), 51.82 (OCH ),
C
1
3
4
2
6
1
(
93%), mp 31–32°C (from CH Cl –hexane). C NMR
2
2
3
6
spectrum, δ , ppm: 14.10 (CH ), 22.61 (C ), 26.89
156.56 (C=O). Mass spectrum, m/z (I , %): 156 (5)
C
3
rel
3
4
2
5
1
+
(
C ), 28.90 (C ), 30.63 (C ), 31.69 (C ), 41.20 (C ),
[M] , 140 (1), 128 (100), 115 (6), 102 (9), 90 (14), 83
5
1.70 (OCH ), 157.87 (C=O). Mass spectrum, m/z
(5), 67 (3), 55 (10), 28 (2). Found, %: C 60.97; H 9.29;
N 8.22. C H NO . Calculated, %: C 61.12; H 9.62;
3
+
(I , %): 174 (3) [M] , 158 (3), 144 (2), 130 (3), 103
rel
8
15
2
(5), 88 (100), 76 (16), 59 (15), 44 (37), 29 (10).
N 8.91. M 157.210.
Found, %: C 62.97; H 10.99; N 7.82. C H NO . Cal-
culated, %: C 62.39; H 11.05; N 8.08. M 173.252.
9
19
2
Methyl N-cyclohexyl-N-methylcarbamate (5c).
1
3
Yield 0.77 g (45%), bp 85–86°C (1 mm Hg). C NMR
3
5
4
spectrum, δ , ppm: 26.15 (C , C ), 26.48 (C ), 31.29
Methyl N-heptyl-N-methylcarbamate (2c). Yield
C
2
6
1
1
3
(C , C ), 41.28 (CH ), 56.42 (C ), 51.22 (OCH ),
0
.898 g (48%), bp 94–95°C (5 mm Hg). C NMR
3
3
6
158.06 (C=O). Found, %: C 62.97; H 9.51; N 8.42.
C H NO . Calculated, %: C 63.13; H 10.01; N 8.18.
spectrum, δ , ppm: 14.10 (CH ), 22.68 (C ), 27.89
C ), 29.25 (C ), 29.89 (C ), 32.29 (C ), 33.65 (NCH ),
0.60 (C ), 52.17 (OCH ), 156.87 (C=O). Found, %:
C
3
3
2
4
5
(
5
9
17
2
3
1
M 171.236.
3
C 63.85; H 10.97; N 6.92. C H NO . Calculated, %:
C 64.13; H 11.30; N 7.48. M 187.279.
Methyl N-cycloheptylcarbamate (6b). Yield
1.54 g (90%), bp 89–90°C (1 mm Hg). C NMR
1
0
21
2
1
3
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 56 No. 7 2020

METHOXYCARBONYLATION OF ALKYL-, CYCLOALKYL-, AND ARYLAMINES
1233
3
6
4
5
spectrum, δ , ppm: 22.64 (C , C ), 31.57 (C , C ),
1453 s, 1505 m, 1546 s, 1605 s, 1615 m, 1709 s,
C
2
7
1
13
3
6.33 (C , C ), 51.12 (C ), 51.79 (OCH ), 156.26
3322 m. C NMR spectrum, δ , ppm: 52.35 (OCH ),
3
C
3
+
2
6
4
3
5
(
1
(
C=O). Mass spectrum, m/z (I , %): 171 (10) [M] ,
118.81 (C , C ), 123.48 (C ), 128.89 (C , C ), 138.61
(C ), 154.72 (C=O). Mass spectrum, m/z (Irel, %): 151
(100) [M] , 135 (4), 119 (75), 106 (97), 92 (48),
rel
1
56 (15), 142 (15), 128 (60), 114 (100), 101 (40), 96
60), 88 (55), 82 (56), 76 (100), 59 (50), 41 (72), 40
100). Found, %: C 62.97; H 9.69; N 7.82. C H NO .
+
(
77 (30), 65 (80), 51 (20), 39 (40), 28 (10). Found, %:
9
17
2
C 62.97; H 5.89; N 8.92. C H NO . Calculated, %:
Calculated, %: C 63.13; H 10.01; N 8.18. M 171.236.
8
9
2
C 63.56; H 6.00; N 9.27. M 151.162.
Methyl N-(2-methylphenyl)carbamate (10b).
Yield 0.743 g (45%), mp 67–68°C (from CH Cl –
Methyl N-cycloheptyl-N-methylcarbamate (6c).
Yield 0.833 g (45%), bp 95–96°C (3 mm Hg).
1
3
3
6
C NMR spectrum, δ , ppm: 23.86 (C , C ), 28.02
2
2
C
13
4
5
2
7
hexane); published data [19]: mp 69–69.3°C. C NMR
spectrum, δ , ppm: 15.57 (CH ), 52.52 (OCH ), 121.75
(
5
(
(
(
C , C ), 30.21 (CH ), 35.33 (C , C ), 51.79 (OCH ),
3
3
1
7.72 (C ), 156.26 (C=O). Mass spectrum, m/z
I , %): 185 (10) [M] , 170 (1), 156 (1), 142 (2), 128
C
3
3
6
4
5
1
+
(C ), 124.79 (C ), 127.45 (C ), 128.88 (C ), 130.87
C ), 138.95 (C ), 154.73 (C=O). Found, %: C 64.87;
rel
3
1
(
100), 114 (45), 102 (20), 96 (20), 90 (20), 76 (10), 71
10), 59 (10), 41 (25), 42 (30), 40 (90). Found, %:
H 5.99; N 8.12. C H NO . Calculated, %: C 65.44;
9
11
2
H 6.71; N 8.48. M 165.189.
C 63.87; H 9.89; N 7.28. C H NO . Calculated, %:
1
0
19
2
C 64.83; H 10.34; N 7.56. M 185.263.
Methyl N-(3-methylphenyl)carbamate (11b).
Yield 0.743 g (45%), mp 69–70°C (from CH Cl –
2
2
Methyl N-cyclooctylcarbamate (7b). Yield
13
1
3
hexane); published data [19]: mp 69–69.3°C. C NMR
1
.684 g (91%), bp 115–115.5°C (2 mm Hg). C NMR
3
7
5
spectrum, δC, ppm: 21.27 (CH3), 52.65 (OCH3), 115.92
spectrum, δ , ppm: 23.50 (C , C ), 26.44 (C ), 27.22
C
6
2
4
5
4
6
2
8
1
(C ), 118.86 (C ), 123.29 (C ), 130.55 (C ), 138.08
(
(
1
[
1
C , C ), 31.56 (C , C ), 50.91 (C ), 51.57 (OCH ),
3
3
1
C ), 138.95 (C ), 154.83 (C=O). Found, %: C 64.99;
56.40 (C=O). Mass spectrum, m/z (I , %): 185 (45)
rel
H 6.19; N 8.32. C H NO . Calculated, %: C 65.44;
+
9
11
2
M] , 170 (48), 156 (49), 142 (100), 128 (99), 114 (97),
01 (95), 76 (96), 56 (88), 40 (91). Found, %: C 63.97;
H 9.99; N 7.22. C H NO . Calculated, %: C 64.83;
H 6.71; N 8.48. M 165.189.
Methyl N-(4-methylphenyl)carbamate (12b).
Yield 1.452 g (88%), mp 97.5–98.5°C (from cyclo-
hexane); published data [18]: mp 98.3–99°C. IR spec-
1
0
19
2
H 10.34; N 7.56. M 185.263.
Methyl N-cyclooctyl-N-methylcarbamate (7c).
–
1
trum (KBr), ν, cm : 816 m, 1073 m, 1236 s, 1317 m,
512 m, 1538 m, 1599 m, 1704 s, 3328 m. 13C NMR
spectrum, δ , ppm: 20.65 (CH ), 52.35 (OCH ), 118.84
Yield 0.916 g (46%), bp 100–101°C (2 mm Hg).
1
13
3
7
C NMR spectrum, δ , ppm: 24.96 (C , C ), 25.38
C
4
6
5
2
8
C
3
3
(
(
C , C ), 26.06 (C ), 27.22 (CH ), 32.34 (C , C ), 51.91
OCH ), 57.79 (C ), 156.48 (C=O). Mass spectrum,
m/z (I , %): 199 (5) [M] , 184 (0.5), 170 (1), 156 (1),
2
6
3
5
4
1
3
(
C , C ), 129.48 (C , C ), 132.84 (C ), 136.65 (C ),
1
3
1
54.73 (C=O). Mass spectrum, m/z (I , %): 165 (100)
rel
+
+
rel
[
M] , 150 (6), 133 (78), 120 (15), 106 (41), 91 (14),
7 (36), 51 (95), 29 (2). Found, %: C 64.97; H 6.09;
N 8.12. C H NO . Calculated, %: C 65.44; H 6.71;
1
7
42 (2), 128 (100), 114 (30), 102 (15), 90 (30), 76 (10),
1 (15), 56 (20), 42 (40), 41 (38), 40 (40). Found, %:
7
9
11
2
C 65.97; H 9.99; N 6.82. C H NO . Calculated, %:
11
21
2
N 8.48. M 165.189.
C 66.29; H 10.62; N 7.03. M 199.289.
Methyl N-(4-chlorophenyl)carbamate (13b).
Methyl N-(adamantan-1-yl)carbamate (8b).
Yield 1.58 g (85%), mp 115–116.5°C (from CH Cl –
2
2
Yield 2.05 g (98%), mp 117–119°C (from CH Cl –
2
2
hexane); published data [18]: mp 115.6–116.1°C. IR
hexane) {118–120°C [18]}. IR spectrum (KBr), ν,
–1
spectrum (KBr), ν, cm : 1092, 1238, 1546, 1606,
–
1
13
1
3
cm : 1722 (C=O), 3271 (NH). C NMR spectrum, δ ,
C
2
1704, 3345. C NMR spectrum, δ , ppm: 52.65
C
3
5
7
4
6
10
2
6
4
3
5
ppm: 29.95 (C , C , C ), 36.38 (C , C , C ), 41.29 (C ,
C , C ), 51.02 (C ), 51.22 (OCH ), 154.98 (C=O).
Mass spectrum, m/z (I , %): 209 (35) [M] , 152 (100),
(
OCH ), 120.18 (C , C ), 128.34 (C ), 129.08 (C , C ),
137.05 (C ), 154.43 (C=O). Mass spectrum, m/z
(I , %): 185 (44) [M] , 153 (46), 140 (39), 128 (11),
3
8
9
1
1
3
+
+
rel
rel
1
20 (68). Found, %: C 67.97; H 9.89; N 6.22.
112 (8), 99 (29), 90 (17), 73 (20), 62 (25), 49 (18),
32 (100). Found, %: C 50.97; H 4.09; Cl 18.85; N 7.22.
C H ClNO . Calculated, %: C 51.77; H 4.34; Cl 19.10;
C H NO . Calculated, %: C 68.87; H 9.15; N 6.69.
1
2
19
2
M 209.284.
Methyl N-phenylcarbamate (9b). Yield 1.299 g
86%), mp 45–46.5°C (from cyclohexane); published
8
8
2
N 7.55. M 185.607.
(
Methyl N-(4-bromophenyl)carbamate (14b).
–
1
data [18]: mp 47–48°C. IR spectrum (KBr), ν, cm :
10 m, 730 m, 905 m, 1032 m, 1072 s, 1247 s, 1324 s,
Yield 2 g (87%), mp 125–126°C (from CH Cl –
2
2
7
hexane); published data [18]: mp 125.1–125.7°C.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 56 No. 7 2020

1234
KHUSNUTDINOV et al.
1
3
C NMR spectrum (CDCl ), δ , ppm: 52.65 (OCH ),
ACKNOWLEDGMENTS
3
C
3
4
2
6
3
5
1
16.34 (C ), 120.15 (C , C ), 131.58 (C , C ), 136.15
1
(C ), 153.73 (C=O). Found, %: C 40.97; H 3.09;
This study was performed using the equipment of Agidel
joint center, Ufa Federal Research Center, Russian Academy
of Sciences.
Br 33.85; N 5.82. C H BrNO . Calculated, %: C 41.77;
H 3.50; Br 34.73; N 6.09. M 230.058.
8
8
2
Methyl N-(4-nitrophenyl)carbamate (15b). Yield
FUNDING
1
.686 g (86%), mp 176.5–178°C (from CH Cl –
2 2
hexane); published data [18]: mp 177.2–178°C. IR
–
1
This study was performed under financial support by the
Ministry of Science and Higher Education of the Russian
Federation (project no. 2019-05-595-000-058).
spectrum (KBr), ν, cm : 1220, 1326, 1506, 1596,
740, 3394. 1 C NMR spectrum, δ , ppm: 52.65
3
1
(
1
C
2
6
3
5
1
OCH ), 117.38 (C , C ), 125.08 (C , C ), 143.05 (C ),
3
4
46.04 (C ), 154.83 (C=O). Found, %: C 47.97;
CONFLICT OF INTEREST
The authors declare no conflict of interest.
REFERENCES
H 3.89; N 13.42. C H N O . Calculated, %: C 48.98;
H 4.11; N 14.28. M 196.160.
8
8
2
4
Methyl N-benzylcarbamate (16b). Yield 1.6 g
(
97%), mp 64–65°C (from CH Cl –hexane; published
2 2
data [20]: mp 62.2–62.9°C. IR spectrum (KBr), ν,
–1
cm : 704, 739, 999, 1144, 1273 s, 1495 m, 1536 s,
1
2
3
. Rose, S.L., Sullivan, H.R., and Pohland, A., J. Am.
Pharm. Assoc., 1955, vol. 44, p. 766.
https://doi.org/10.1002/jps.3030441217
1
3
1
(
1
692 s, 3344 m. C NMR spectrum, δ , ppm: 45.07
C
4
2
6
CH ), 52.25 (OCH ), 127.29 (C ), 127.55 (C , C ),
2 3
3
5
1
28.08 (C , C ), 137.65 (C ), 156.83 (C=O). Mass
. Konopacki, J., Gołebiewski, H., and Eckersdorf, B.,
Brain Res., 1992, vol. 572, p. 76.
https://doi.org/10.1016/0006-8993(92)90453-G
+
spectrum, m/z (I , %): 165 (40) [M] , 150 (78), 133
rel
(
6
32), 121 (9), 106 (12), 91 (100), 79 (66), 77 (10),
5 (29), 59 (12), 29 (9). Found, %: C 64.87; H 6.19;
N 7.82. C H NO . Calculated, %: C 65.44; H 6.71;
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Contact Dermatitis, 1997, vol. 36, p. 156.
https://doi.org/10.1111/j.1600-0536.1997.tb00400.x
9
11
2
N 8.48. M 165.189.
Methyl N-benzyl-N-methylcarbamate (16c).
4. Fukuto, T.R., Environ. Health Perspect., 1990, vol. 87,
p. 245.
Yield 1.003 g (56%), colorless oil, R 0.44 (hexane–
f
–
1
EtOAc, 2:1). IR spectrum (KBr), ν, cm : 701, 771,
144, 1146 s, 1454 m, 1484, 1536 s, 1705 s, 2955,
030 m. 13C NMR spectrum (DMSO-d ), δ , ppm:
https://doi.org/10.1289/ehp.9087245
1
3
3
5. Daly, N.J. and Ziolkowski, F., Aust. J. Chem., 1972,
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6
C
2
5.7 (CH ), 52.29 (OCH ), 53.74 (CH ), 126.97 (C ,
https://doi.org/10.1071/CH9721453
3
3
2
6
4
3
5
1
C ), 127.56 (C ), 128.02 (C , C ), 137.68 (C ), 156.45
C=O). Found, %: C 66.87; H 6.99; N 7.72.
C H NO . Calculated, %: C 67.02; H 7.31; N 7.82.
6. Tundo, P., Bressanello, S., Loris, A., and Sathicq, G.,
Pure Appl. Chem., 2005, vol. 77, p. 1719.
(
https://doi.org/10.1351/pac200577101719
1
0
13
2
M 179.215.
7. Cao, Y.L., Zhao, L.S., Wang, L.J., Zhu, G., Wang, L.,
He, P., and Li, H., Int. J. Chem. Kinet., 2018, vol. 50,
p. 767.
N-Benzylidenebenzylamine (16d). Yield 0.488 g
1
3
(25%), bp 124–125°C (2 mm Hg). C NMR spectrum,
https://doi.org/10.1002/kin.21211
2
6
3
δ , ppm: 65.05 (PhCH ), 127.98 (C , C ), 128.49 (C ,
C
2
5
3′
5′
4
4′
8. Baba, T., Fujiwara, M., Oosaku, A., Kobayashi, A.,
Deleon, R., and Ono, Y., Appl. Catal., A, 2002,
vol. 227, p. 1.
C ), 128.60 (C , C ), 128.63 (C ), 130.76 (C ), 136.17
1′
1
(
C ), 139 (C ), 162.00 (N=CH). Mass spectrum, m/z
+
(
I , %): 195.25 (35) [M] , 194 (33), 165 (5), 152 (3),
rel
https://doi.org/10.1016/S0926-860X(01)00939-5
117 (15), 91 (100), 65 (20), 51 (5). Found, %: C 85.87;
9
. Li, F., Miao, J., Wang, Y., and Zhang, X., Ind. Eng.
Chem. Res., 2006, vol. 45, p. 4892.
H 6.19; N 6.92. C H N. Calculated, %: C 86.12;
H 6.71; N 7.17. M 195.2597.
1
0
21
https://doi.org/10.1021/ie060142n
N-Butyl-N-methylbutan-1-amine (17b). Yield
1
0. Guo, X., Shang, J., Li, J., Wang, L., Ma, Y., Shi, F., and
Deng, Y., Synth. Commun., 2011, vol. 41, p. 1102.
https://doi.org/10.1080/00397911003707055
1
3
1
.418 g (99%), bp 85–86°C (50 mm Hg). C NMR
4
4′
3
3′
spectrum, δ , ppm: 14.60 (C , C ), 21.10 (C , C ),
C
2
2′
1
1′
2
9.31 (C , C ), 42.18 (NCH ), 58.21 (C , C ).
3
11. Vauthey, I., Valot, F., Gozzi, C., Fache, F., and
Lemaire, M., Tetrahedron Lett., 2000, vol. 41, p. 6347.
https://doi.org/10.1016/S0040-4039(00)01051-0
Found, %: C 76.87; H 13.99; N 9.12. C H N. Cal-
9
21
culated, %: C 75.45; H 14.77; N 9.78. M 143.269.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 56 No. 7 2020

METHOXYCARBONYLATION OF ALKYL-, CYCLOALKYL-, AND ARYLAMINES
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https://doi.org/10.1021/je60085a001
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3. Kutepov, B.I., Travkina, O.S., Pavlova, I.N., Khazipo-
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4. Pavlov, M.L., Travkina, O.S., Kutepov, B.I., Pavlo-
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RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 56 No. 7 2020