Synthesis of (η6-arene)tricarbonylchromium derivatives of 1,4-dihydro-3,1-benzoxazines

Article abstract of DOI:10.1007/s11172-021-3073-y

A series of (η⁶-arene)tricarbonylchromium derivatives of 1,4-dihydro-3,1-benzoxazines was synthesized and characterized. The compounds were obtained by two alternative methods, namely, by the reaction of triammine(tricarbonyl)chromium with 1,4-dihydro-3,1-benzoxazines (method A) and by the condensation of (η⁶-2-aminobenzyl alcohol)tricarbonylchromium with various aldehydes and ketones (method B). The composition and structure of obtained compounds were established by different physicochemical methods of analysis, such as HPLC, UV, IR, ¹H NMR spectroscopy, mass spectrometry, and X-ray diffraction.

Full text of DOI:10.1007/s11172-021-3073-y

Russian Chemical Bulletin, International Edition, Vol. 70, No. 1, pp. 171—178, January, 2021
171
6
Synthesis of (η -arene)tricarbonylchromium derivatives
of 1,4-dihydro-3,1-benzoxazines
E. V. Sazonova, A. N. Artemov, V. I. Faerman, N. A. Aksenova, A. A. Timofeeva,
Yu. A. Zaytseva, N. V. Somov, and N. Yu. Grishina
Lobachevsky State University of Nizhny Novgorod,
korp., 23 prosp. Gagarina, 603950 Nizhny Novgorod, Russian Federation.
Fax: +7 (831) 465 8162. E-mail: zarovkinan@mail.ru
5
6
A series of (η -arene)tricarbonylchromium derivatives of 1,4-dihydro-3,1-benzoxazines was
synthesized and characterized. The compounds were obtained by two alternative methods,
namely, by the reaction of triammine(tricarbonyl)chromium with 1,4-dihydro-3,1-benzoxazines
6
(
method A) and by the condensation of (η -2-aminobenzyl alcohol)tricarbonylchromium with
various aldehydes and ketones (method B). The composition and structure of obtained com-
pounds were established by different physicochemical methods of analysis, such as HPLC, UV,
1
IR, Н NMR spectroscopy, mass spectrometry, and X-ray diffraction.
6
Key words: ( -arene)tricarbonylchromium, 1,4-dihydro-3,1-benzoxazines, heterocyclic
compounds, triammine(tricarbonyl)chromium.
Heterocycles are important structural fragments in the
molecules of various organic compounds with biological
activity.1 The presence of metal tricarbonyl fragments,
in particular, the chromium tricarbonyl group, can sig-
nificantly expand the field of application of these com-
substituted oxazolidines and oxazinanes, the р,-conju-
gation of the lone electron pair of the nitrogen atom of
the heterocyclic ring with the phenyl substituent decreases
the nucleophilicity of the nitrogen atom, which prevents the
,2
formation of the N—Cr -bond and finally leads to
6
6
pounds. There are known derivatives containing (η -benz-
(η -arene)Cr(CO) derivatives of these compounds. To
3
ene)Cr(CO) groups and heterocyclic fragments, which
synthesize the target chromium-containing heterocycles,
in this work we used two approaches. The first consisted
in the reaction of triammine(tricarbonyl)chromium
(TATC (1)) with the corresponding 1,4-dihydro-3,1-
benzoxazines 2a—k (Scheme 1 , method A), in the mol-
ecules of which there is a conjugation of the nitrogen atom
with the arene part. The second method consisted in the
construction of heterocyclic fragments by the condensa-
3
have properties making them promising for use in mo-
lecular biotechnology and biomedicine. In particular,
peptide nucleic acids, reagents for labeling proteins, bio-
6
probes, and tracers for drugs containing (η -arene)-
Cr(CO) fragments were obtained. The use of Cr(CO)
3
3
complexes for biomedical purposes is primarily due to
their unique spectroscopic characteristics, in particular,
the presence of very intense characteristic absorption bands
of CO groups in the mid-IR region, which allows sensitive
6
tion reaction of (η -1-amino-2-hydroxymethylbenzene)-
tricarbonylchromium (3) with various carbonyl com-
pounds 4a—k (see Scheme 1, method B).
3
detection even in complex biological matrices.
6
Heterocyclic (η -benzene)Cr(CO) derivatives are widely
To synthesize chromium-containing 1,4-dihydro-3,1-
benzoxazines 5a—k by method A, at the first stage of our
work we obtain heterocycles 2a—k using a procedure
3
used in fine organic synthesis because of their high chem-
ical potential of both the heterocyclic rings and the Cr(CO)3
group, which, due to its bulkiness and pronounced elec-
tron-withdrawing properties, is capable of promoting
1
7
described in the work, which consisted in the reaction
of amino alcohols with carbonyl compounds in THF
and the presence of magnesium sulfate. Heating of carb-
4
—9
highly diastereo- and enantioselective syntheses.
6
Continuing our research on the synthesis of (η -arene)-
onyl compounds 4a—k and 2-aminobenzyl alcohol at
50—100 С for 3—10 h gave products 2a—k1
8—22
in good
Cr(CO) complexes with N,O-heterocyclic rings in the
3
1
0—16
composition,
we obtained chromium-containing
yields (see Experimental). At the second stage, the reaction
of heterocyclic compounds 2a—k with TATC (1) in di-
oxane upon heating (120 С) for 4—6 h (see Experimental)
gave the target products 5 (see Scheme 1, method A). It
was found that compounds 5h,j,k containing prop-1-en-
1-yl, 2-furyl, and 2-pyridyl substituents, respectively,
cannot be obtained by this method (only starting compo-
1
,4-dihydro-3,1-benzoxazines.
Results and Discussion
Earlier, we have shown16 that in the reaction of
triammine(tricarbonyl)chromium (1) with N-phenyl-
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 171—178, January, 2021.
066-5285/21/7001-0171 © 2021 Springer Science+Business Media LLC
1

1
72
Russ. Chem. Bull., Int. Ed., Vol. 70, No. 1, January, 2021
Sazonova et al.
Scheme 1
A: dioxane, 120 C; B: MgSO , THF, 25—80 C.
4
2
a
b
c
, 4, 5
R1
H
Me
R2
H
Me
2, 4, 5
R1
Me
H
R2
Et
Me
Et
2, 4, 5
R1
H
H
R2
2, 4, 5
R1
H
H
R2
d
e
f
g
h
i
Bu
Prop-1-en-1-yl
Ph
j
Furan-2-yl
Pyridin-2-yl
k
Spirocyclohexane
H
H
nents were recovered from the reaction mixtures). This
of the heterocyclic ring and has a tetrahedral chirality,
while the other with planar chirality is located in the benz-
ene part of the ligand), these substances can exist as two
racemic diastereomers, which for compounds 5e—k we
2
3,24
experimental fact was not surprising, since it is known
that most unsaturated hydrocarbons, as well as some
heterocycles such as furan and pyridine derivatives, do not
give the corresponding Cr(CO) --complexes when react-
designated as trans and cis isomers, indicating the mutual
3
2
ing with chromium hexacarbonyl or TATC.
position of substituent R and Cr(CO) group relative to
3
Method B turned out to be more versatile: the conden-
sation reactions of chromium-containing amino alcohol
the heterocyclic ring.
3
with carbonyl compounds 4a—k under conditions
similar to the processes for the preparation of heterocycles
a—k (see Experimental) made it possible to successfully
synthesize the entire series of chromium-containing
,4-dihydro-3,1-benzoxazines 5a—k (see Scheme 1). The
2
1
final product yields varied within the ranged of 25—85%.
The presence of the Cr(CO) group in the amino alcohol
3
molecule did not significantly affect the course of conden-
sation reactions in comparison with the reactions in which
compounds 2a—k were prepared.
Comparing the syntheses of compounds 5 by methods
A and B showed that in the reaction of heterocycles 2d—k
with TATC (1), diastereomers were formed in a ratio close
to 1 : 1, while the condensation method, as a rule,
gave a higher content of trans isomers in the mixture of
product (Table 1). The greatest effect on the ratio of dia-
6
Note that (η -1-amino-2-hydroxymethylbenzene)-
tricarbonylchromium (3) was obtained and characterized
by us for the first time. Its synthesis was carried out by the
reaction of TATC (1) with 2-aminobenzyl alcohol in re-
fluxing dioxane for 1.5 h (Scheme 2). Product 3, obtained
in 91% yield, was a yellow crystalline solid with m.p.
Table 1. The ratio of diastereomers of compounds
1
3
13—114 C. The spectral characteristics of amino alcohol
a
5
d—k obtained by methods А and B
are given in the Experimental.
Compound
Ratio trans/cis
Scheme 2
Method А
Method B
5
5
5
5
5
5
5
5
db
e
f
g
h
i
1.0 : 1.0
1.0 : 1.0
1.0 : 1.0
1.0 : 1.0
1.0 : 1.0
1.3 : 1.0
1.6 : 1.0
2.0 : 1.0
1.2 : 1.0
3.0 : 1.0
3.3 : 1.0
с
—
1.2 : 1.0
с
j
k
—
—
с
d
—
a
Determined from the ratio of peak areas of the
Reagents and conditions: dioxane, 120 C, 1.5 h.
products in HPLC chromatograms at λ = 318 nm.
b
The data are given for diastereomers 5d.
с
Since most of the target heterocycles 5 contain two
asymmetric centers (one of which is located at position 2
Method A did not give the compound.
d
Only trans-isomer was formed.

Dihydro-3,1-benzoxazines with Cr(CO) -group
Russ. Chem. Bull., Int. Ed., Vol. 70, No. 1, January, 2021
173
3
Table 2. Some characteristics of the compounds 5a—k
All of the isolated compounds 5a—k were yellow crys-
talline substances, relatively stable in air, the purity of
which was confirmed by HPLC. Their IR spectra exhibited
strong absorption bands of stretching vibrations of the
Com-
pound
Yield (%)a
M.p./C
IR (KBr),
ν(С≡О)/cm
–
1
А
В
CO groups of Cr(CO) fragments in the region of 1832—
3
5
5
5
5
a
b
c
d
64
79
76
39
42
36
32
35
85
81
33
25
43
42
30
56
18
52
33
117—119
130—132
160—162
120—122
111—112
141—142
116—117
98—100
150—152
163—165
123—125
137—138
1940, 1866, 1848
1936, 1860, 1835
1938, 1855,1832
1937, 1878, 1841
1947, 1859
–1
1
967 cm (see Table 2), as well as other absorption
bands characteristic of the heterocycles under study (see
Experimental).
b
1H NMR spectroscopy also confirmed the structure of
trans-5e
trans-5f
trans-5g
trans-5h
trans-5i
cis-5i
1
,4-dihydro-3,1-benzoxazines 5a—k: the spectra exhibited
1941, 1865
1962, 1894
the signals for the protons of the heterocyclic ring, sub-
с
1
2
6
—
40
35
1957, 1865
stituents R and R , as well as (η -arene)Cr(CO) frag-
3
1967, 1874
ments (see Experimental). The signals of the methylidene
1947, 1869, 1844
1950, 1865, 1850
1947, 1881, 1854
group of the C(4)H atom in the heterocyclic ring turned
2
с
trans-5j
trans-5k
—
—
out to be very informative, which allowed us to distinguish
с
the diastereomers of compounds 5e—k. As can be seen
a
The yield is given for the purified product after column chrom-
atography and recrystallization.
from Table 3, the OCH group of cis-isomeric products
2
resonates as two doublets with a spin-spin coupling con-
stant of 14.1—14.5 Hz and a difference in the chemical
shift values of these protons at a level of 0.32—0.46 ppm,
while for trans-isomers this is either one signal (singlet or
doublet), or two closely positioned doublets with a differ-
ence in the chemical shift values of no more than 0.09 ppm.
The reason for this difference is the spatial arrangement
of the considered protons. In cis-isomer, one of the protons
b
The data are given for isolated diastereomer 5d.
с
Method A did not give the compound.
stereomers was exerted by the presence of bulky phenyl,
2
-furyl, and 2-pyridyl groups in the composition of car-
bonyl compounds (see Table 1).
Products 5a—k obtained by both methods were isolated
from the reaction mixtures by column chromatography
on silica gel, eluting with a mixture of hexane—ethyl ac-
etate. Compounds presented in Table 2 were isolated in
the pure form and characterized by HPLC, UV, IR,
of the OCH fragment is shielded simultaneously by both
2
2
the Cr(CO) group and the R substituent at the C(2) atom,
3
which ultimately leads to a significantly greater difference
in the chemical shift values of these protons as compared
to that for trans-isomer, in which there is no such double
shielding and the protons are more equivalent. For com-
1
H NMR spectroscopy, and mass spectrometry. The cis-
isomers of products 5e—k (except for compound cis-5i)
were isolated by column chromatography in mixtures with
some amounts of the corresponding trans-products. In
pound 5d, the protons of the OCH fragment are non-
2
equivalent in both diastereomers due to the shielding by the
Cr(CO) group, the methyl or ethyl substituent of one of
3
1
a number of cases, it was possible to describe H NMR
the proton in the pair. This is reflected in the separation
1
spectra of cis-isomers based on the spectrum of a mixture
of the doublets of these protons in the H NMR spectra
of diastereomers (see Experimental).
by ~0.3 ppm for each diastereomer (see Experimental).
Table 3. Chemical shift values for the OCH protons of trans- and cis-isomers of heterocycles 5e—k
2
Com-
pound 5
trans-5
cis-5
δ(OCH2)
Δ(δ(OCH ))
δ(OCH2)
Δ(δ(OCH ))
2
2
(
J/Hz)
(J/Hz)
e
4.71 (d, 2 Н, J = 5.5)
0
4.38 (d, 1 Н, J = 14.1);
0.39
4
.77 (d, 1 Н, J = 14.1)
a
a
f
g
4.72 (s, 2 H)
4.72 (s, 2 H)
0
0
—
—
4.41 (d, 1 Н, J = 14.1);
0.36
4
.77 (d, 1 Н, J = 14.1)
a
a
h
i
4.71 (d, 2 H, J = 2.0)
4.78 (d, 1 H, J = 14.5);
0
—
—
0.09
4.57 (d, 1 Н, J = 14.5);
5.03 (d, 1 H, J = 14.5)
4.52 (d, 1 H, J = 14.5);
4.98 (d, 1 H, J = 14.5)
0.46
0.46
— b
4
.87 (d, 1 H, J = 14.5)
j
4.64 (d, 1 H, J = 14.5);
.69 (d, 1 H, J = 14.5)
4.90 (d, 1 H, J = 14.5);
.98 (d, 1 H, J = 14.5)
0.05
0.08
4
b
k
—
4
a
Spectrum for cis-isomer was not recorded.
Only trans-isomer was obtained.
b

1
74
Russ. Chem. Bull., Int. Ed., Vol. 70, No. 1, January, 2021
Sazonova et al.
C(10)
C(7)
O(1)
C(11)
C(8)
C(17)
C(6)
O(3)
C(9)
C(2)
C(5)
C(12)
C(14)
C(16)
N(1)
C(4)
Cr(1)
C(13)
C(15)
C(1)
C(3)
O(2)
O(4)
Fig. 1. Molecular structure of the compound cis-5i.
The structures of compounds 5с, trans-5e, and cis-5i
containing spirocyclohexane, methyl, and phenyl sub-
stituents at the C(2) atom, respectively, was also confirmed
by X-ray diffraction data. The specific features of the
ment are close to 90 (87.8(2)—91.2(2)), which is typical
6
27
of (η -arene)Cr(CO) complexes.
3
6
For the obtained series of (η -arene)tricarbonylchrom-
ium derivatives 5a—k, electron impact mass spectra were
recorded and their fragmentation was studied. As in the
structures of compounds 5с and trans-5e were described
earlier in the works.2
5,26
The molecular structure of cis-5i
case of other transition metal carbonyl complexes, the
28
+
complex is shown in Fig. 1. Table 4 contains the principal
bond lengths and bond angles in this compound.
X-ray diffraction analysis of compound cis-5i con-
primary fragmentation of molecular ions [M] consisted
in the stepwise dissociation of three carbonyl groups, which
+
led to the formation of fragments [F ] (see Scheme 3).
1
firmed that the phenyl substituent and the Cr(CO) group
Further, for all analyzed samples the main direction of
3
are located on the same side of the heterocyclic ring. It
was shown that the heterocyclic part of molecule cis-5i
has a half-chair conformation: all atoms, except for the
oxygen atom, lie practically in the same plane. The hy-
fragmentation was the elimination of water molecule to
+
2
obtain [F ] and further elimination of substituent R (in
2
the case of compound 5c, the elimination of the С Н
5
10
+
fragment) with the formation of [F3] (see Scheme 3,
Table 5). The elimination of water and the substituent at
the C(2) atom from dihydro-3,1-benzoxazine molecules
during fragmentation under electron impact is confirmed
2
bridization of the nitrogen atom is close to sp (the angle
C(9)—N(1)—C(11) is equal to 119.4(2)). The bond
lengths of the heterocyclic ring are in the range 1.377(3)—
2
9
1
.497(5) Å, while the C(8)—C(9) distance is closer to
by the literature data.
that in arenes and is equal to 1.398(4) Å. The distance
between the heterocyclic ring and the phenyl substituent
In conclusion, this study resulted in the synthesis of
new (η -arene)tricarbonylchromium derivatives of 1,4-di-
6
(
С(11)—С(12)) is equal to 1.502(5) Å. The Cr—Carene
hydro-3,1-benzoxazines 5a—k, which were characterized
by various methods. These compounds were obtained by
two alternative methods, namely, by the reaction of het-
erocyclic compounds 2a—k with triammine(tricarbonyl)-
bond lengths in cis-5i are close to each other and lie in the
range 2.196(3)—2.331(3) Å. The Cr—C(СО) distances are
1
.810(3)—1.819(4) Å, and the angles in the Cr(CO) frag-
3
Table 4. Principal bond distances (d) and bond angles (ω) for the structure cis-5i
Bond
d/Å
Bond
d/Å
Bond
d/Å
Angle
ω/deg
C(10)—O(1)
C(11)—O(1)
C(11)—N(1)
C(9)—N(1)
C(8)—C(9)
C(8)—C(10)
C(11)—C(12)
C(12)—C(13)
C(13)—C(14)
1.425(4)
1.409(4)
1.461(5)
1.377(3)
1.398(4)
1.497(5)
1.502(5)
1.387(5)
1.375(6)
C(14)—C(15)
C(15)—C(16)
C(16)—C(17)
C(12)—C(17)
C(4)—C(9)
C(4)—C(5)
C(5)—C(6)
C(6)—C(7)
C(7)—C(8)
1.355(8)
1.355(8)
1.377(6)
1.370(6)
1.412(5)
1.389(5)
1.396(4)
1.396(5)
1.411(5)
C(4)—Cr(1)
C(5)—Cr(1)
C(6)—Cr(1)
C(7)—Cr(1)
C(8)—Cr(1)
C(9)—Cr(1)
C(1)—Cr(1)
C(2)—Cr(1)
C(3)—Cr(1)
2.242(3)
2.196(3)
2.217(3)
2.205(3)
2.257(3)
2.331(3)
1.815(3)
1.810(3)
1.819(4)
C(9)—N(1)—C(11) 119.4(2)
N(1)—C(11)—O(1) 109.3(3)
C(10)—O(1)—C(11) 111.3(2)
C(8)—C(10)—O(1) 110.1(3)
C(9)—C(8)—C(10)
C(8)—C(9)—N(1)
C(1)—Cr(1)—C(2)
C(2)—Cr(1)—C(3)
C(1)—Cr(1)—C(3)
118.5(3)
119.6(2)
191.2(2)
187.8(2)
190.6(2)

Dihydro-3,1-benzoxazines with Cr(CO) -group
Russ. Chem. Bull., Int. Ed., Vol. 70, No. 1, January, 2021
175
3
Scheme 3
Products 5a—k were isolated and purified by column chro-
matography using Acros 0.035—0.070 mm silica gel under argon
atmosphere, eluent hexane—ethyl acetate. HPLC analysis was
carried out on a Knauer Smartline 5000 chromatograph with
a S 2600 UV diode array detector (UV spectra of eluates were
recorded in the range of 200—500 nm), a Diasfer-110-S16 col-
umn, 5 μm, 4.6×250 mm, eluent acetonitrile—water (84 : 16);
–
1
the flow rate of the eluent was 0.7 mL min . IR spectra were
recorded on an FTIR-8400S instrument (Shimadzu) in the wave
number range of 500—4000 cm in KBr pellets. 1H NMR
–1
spectra were recorded in acetone-d6 on an Agilent DD2 NMR
4
00NB spectrometer (400 MHz). Mass spectrometric studies
were carried out on a Trace DSQII instrument, ionization by
electron impact (70 eV), m/z range of 70—500, temperature
programming from 50 to 450 C at a heating rate of 100 deg min
–1
.
6
(
η -1-Аminо-2-hydroxymethylbenzene)tricarbonylchromium
(
4
3). 2-Aminobenzyl alcohol (5.00 g, 41 mmol), TATC (1) (7.6 g,
1 mmol), and dioxane (60 mL) were placed into a pre-deaer-
Table 5. Mass spectrometry data for compounds 5a—k (EI, 70 eV),
m/z (Irel (%))
ated and then filled with argon two-neck flask, equipped with
a reflux condenser and a gas burette with dibutyl phthalate. The
reaction mixture was heated for 1.5 h in an oil bath at 120 C
until 2.7 L of ammonia were evolved. Then, the flask was cooled
and filled with argon. The resulting mixture was filtered on
a Schott filter filled with aluminum oxide, the solvent was
evaporated. The residue was recrystallized from a mixture of
hexane—ethyl acetate (9 : 1). Product 3 was obtained as a yellow
powder. The yield was 91%, m.p. 113—114 C. HPLC: one peak,
[M]+
[F1]+
[F2]+
[F3]+
Com-
pound
5
5
5
5
а
b
c
d
271 (100)
299 (33)
339 (23)
313 (37)
285 (67)
299 (36)
327 (64)
311 (52)
347 (36)
347 (19)
337 (39)
348 (15)
187 (15)
215 (100)
255 (100)
229 (100)
201 (100)
215 (40)
243 (100)
227 (98)
263(76)
169 (29)
197 (68)
237 (46)
211 (54)
183 (51)
197 (52)
225 (28)
168 (28)
182 (59)
167 (5)
182 (22)
168 (60)
168 (25)
168 (65)
a
trans-5e
trans-5f
trans-5g
trans-5h
trans-5i
cis-5i
 = 4.6 min. UV (МеCN, H O), λ/nm: 218, 315. IR (KBr),
2
–
1
ν/cm : 3591, 3477, 3364 (ν(N—H, O—H)); 3090 (ν(Carene—H);
2846 (ν(C—H); 1956, 1855, 1836 (ν(C≡O)); 1630, 1547
(ν(Carene— Carene); 671 (ω(Carene—H)). MS (EI, 70 eV), m/z
209 (100) 168 (25)
+
+
+
245 (28)
245 (21)
235 (67)
246 (63)
168 (12)
168 (6)
168 (52)
168 (43)
(Irel (%)): 259 [М] (31), 203 [М – 2 СО] (8.3), 175 [М – 3 СО]
(25), 157 [M – 3 CO – Н О] (100), 52 [Cr] (49). 1H NMR
+
+
263 (85)
253 (79)
264 (100)
2
trans-5j
trans-5k
(acetone-d , 400 МHz), : 4.35—4.54 (m, 3 Н, CH OH); 4.90
6
2
(td, 1 H, Harene, J = 6.3 Hz, J = 0.8 Hz); 5.14 (dd, 1 H, Harene
,
J = 6.7 Hz, J = 0.8 Hz); 5.27 (br.s, 2 H, NH ), 5.69—5.74
2
a
The data are given for isolated diastereomer 5d.
(
m, 1 H, Harene); 5.88 (dd, 1 H, Harene, J = 6.3 Hz, J = 1.2 Hz).
Synthesis of tricarbonylchromium derivatives of 1,4-dihydro-
3
,1-benzoxazines 5a—k (general procedure). Method А. The
reagent TATC (1) (24 mmol) and one of compounds 2a—k
24 mmol), and dioxane (60 mL) were placed into a pre-deaer-
chromium 1 (method A) and by the condensation of
chromium-containing amino alcohol 3 with carbonyl
compounds 4a—k (method B). It was shown that method
B allows one to synthesize a wider range of N—H-
substituted products.
(
ated and then filled with argon two-neck flask, equipped with
a reflux condenser and a gas burette with dibutyl phthalate. The
reaction mixture was heated in an oil bath at 120 C for 4—6 h,
Experimental
Table 6. Reaction time (), temperature (T),
and yields of compounds 2a—k
Solvents were distilled over sodium metal at atmospheric
pressure. Ethyl acetate was dried over calcium chloride and
3
0
2
/h
T/C
Yield (%)
distilled. Commercial paraformaldehyde (4a) and acetaldehyde
(
4e) (Sigma-Aldrich) were used without preliminary purification.
a
b
c
d
e
f
g
h
i
3
7
10
10
3
10
10
10
3
10
8
50
50
50
50
60
60
60
50
100
50
50
68
91
45
43
75
74
57
55
85
48
42
Aldehydes and ketones 4b—d, 4f—k were purified by distillation
at atmospheric or reduced pressure. 2-Aminobenzyl alcohol
(
Sigma-Aldrich) was purified by recrystallization from a mixture
1
8
19
of hexane—ethyl acetate (10 : 1). Compounds 2a—d,f,i, 2e,
2
0
21
22
2
g, 2h, 2j, and 2k were obtained by condensation of alde-
hydes and ketones 4a—k with 2-aminobenzyl alcohol in THF in
the presence of magnesium sulfate according to a procedure
similar to that described in the work.17 The reaction time and
temperature, as well as the yields of compounds 2a—k are pre-
sented in Table 6. Triammine(tricarbonyl)chromium (1) was
synthesized according to the known method.31
j
k

1
76
Russ. Chem. Bull., Int. Ed., Vol. 70, No. 1, January, 2021
Sazonova et al.
then, the flask was cooled and filled with argon. The resulting mix-
ture was filtered on a Schott filter filled with aluminum oxide, the
solvent was evaporated. The residue was subjected to column chrom-
atography to isolate reaction products, which were recrystallized
from a mixture of hexane—ethyl acetate. The yellow crystals formed
were filtered on a Schott filter and then dried in a desiccator.
(ν(N—H)); 3128 (ν(Carene—Н)); 2937 (ν(C—H)); 1938, 1855,
1832 (ν(C≡O)); 1562, 1493 (ν(Carene—Carene)); 818, 788,
+
677 (ω(C
—H)). MS, m/z (I (%)): 339 [M] (23), 283
arene
rel
+
+
+
[M – 2 CO] (6), 255 [M – 3 CO] (100), 237 [M – 3 CO – Н О]
2
(46), 167 [M – 3 CO – С Н10] (5), 157 [M – 4 CO – С Н ]+
+
5
5
10
+
1
(12), 52 [Cr] (65). H NMR, : 1.23—1.39 (m, 1 Н, C H10);
5
6
Method В. (η -1-Аminо-2-hydroxymethylbenzene)tricarb-
1.42—1.75 (m, 7 Н, C H10); 1.80—1.93, 1.95—2.03 (both m,
5
onylchromium (3) (1.6 g, 6 mmol), carbonyl compound 4a or
1 H each, C H ); 4.42 (d, 1 Н, ОCH , J = 14.5 Hz); 4.73 (d, 1 Н,
5 10 2
4
e (12 mmol) or one of compounds 4b—d,f—k (6 mmol), anhydr-
ОCH , J = 14.5 Hz); 4.94 (t, 1 H, Harene, J = 6.3 Hz); 5.09 (d,
2
ous MgSO (2.0 g, 16 mmol), and tetrahydrofuran (5 mL) were
1 H, Harene, J = 7.0 Hz); 5.64 (t, 1 H, Harene, J = 6.3 Hz); 5.83
4
placed into a 10-mL glass tube. The tube was deaerated in liquid
nitrogen, vacuum-sealed, and heated at 25—80 C for 5—9 h.
Then the tube was cooled to room temperature (if necessary) and
unsealed, the reaction mixture was concentrated in vacuo. Further
product isolation was carried out in accordance with the proce-
dure described in method A.
Yields and melting points of compounds 5a—k are given in
Table 2, conditions for the synthesis of these substances are sum-
marized in Table 7.
(d, 1 H, Harene, J = 6.3 Hz); 6.15 (br.s, 1 H, HN).
6
η -(2-Ethyl-2-methyl-1,4-dihydro-2Н-3,1-benzoxazine)tri-
carbonylchromium (5d). Diastereomer 1. HPLC: one peak,
τ = 7.0 min. UV (МеCN, H O), λ/nm: 213, 315, 432. IR (KBr),
2
–
1
ν/cm : 3411 (ν(N—H)); 2924 (ν(C—H)); 1937, 1878, 1841
(ν(C≡O)); 1561, 1493 (ν(Carene—Carene)); 808, 675 (ω(Carene—H)).
+
+
MS, m/z (Irel (%)): 313 [M] (37), 257 [M – 2 CO] (15), 229
+
+
[M – 3 CO] (100), 211 [M – 3 CO – Н О] (54), 182
2
+
+
1
[M – 3 CO – Н О – Et] (22), 52 [Cr] (9). H NMR, : 0.89
2
η6-(1,4-Dihydro-2Н-3,1-benzoxazine)tricarbonylchromium
(t, 3 H, MeCCH Me, J = 7.4 Hz); 1.45 (s, 3 Н, MeCCH Me);
2
2
(
5а). HPLC: one peak,  = 4.9 min. UV (МеCN, H O), λ/nm:
1.57—1.68 (m, 1 Н, CH Me); 1.69—1.80 (m, 1 Н, CH Me);
2
2
2
2
18, 318, 430. IR (KBr), ν/cm– : 3412 (ν(N—H)); 3099
1
4.42 (d, 1 H, ОCH , J = 14.9 Hz); 4.70 (d, 1 H, ОCH , J = 14.9
2 2
(
ν(Carene—H)); 2858 (ν(C—H)); 1940, 1866, 1848 (ν(C≡O));
Hz); 4.95 (td, 1 H, Harene, J = 6.3 Hz, J = 0.8 Hz); 5.07 (dd,
1 H, Harene, J = 6.7 Hz, J = 0.8 Hz); 5.60—5.67 (m, 1 Н, Harene);
1
558, 1489 (ν(Carene—C
)); 819, 677 (ω(Caren e+ —H)). MS,
arene
+
m/z (Irel (%)): 271 [M] (100), 270 [M – Н] (77), 215
5.83 (d, 1 H, H
, J = 6.3 Hz); 6.19 (br.s, 1 H, HN).
arene
+
+
+
+
1
[
(
(
M – 2 CO] (18), 187 [M – 3 CO] (15), 187 [M – 3 CO – 2 Н]
Diastereomer 2. H NMR, : 0.99 (t, 3 H, MeCCH Me, J= 7.4 Hz);
2
+
20), 169 [M – 3 CO – H O] (29), 168 [M – 3 CO – H O– H]
1.32 (s, 3 Н, MeCCH Me); 1.70—1.81 (m, 1 Н, CH Me);
2 2
2
2
28), 167 [M – 3 CO – H O– H] (36), 52 [Cr]+ (14). H NMR,
+
1
1.82—1.92 (m, 1 Н, CH Me); 4.44 (d, 1 H, ОCH , J = 14.5 Hz);
2
2
2

: 4.52 (d, 1 H, NCH OCH , J = 14.1 Hz); 4.65—4.82 (m, 3 H,
4.76 (d, 1 H, ОCH , J = 14.5 Hz); 4.95 (t, 1 H, Harene, J = 6.3 Hz);
2
2
2
NCH OCH , NCH OCH ); 5.03 (t, 1 H, Harene, J = 6.3 Hz);
5.09 (d, 1 H, Harene, J = 7.0 Hz); 5.63 (t, 1 Н, Harene, J = 6.3 Hz);
2
2
2
2
5
5
.16 (d, 1 H, Harene, J = 6.7 Hz); 5.66 (t, 1 H, Harene, J = 6.7 Hz);
5.82 (d, 1 H, Harene, J = 6.3 Hz); 6.16 (br.s, 1 H, HN).
6
.79 (d, 1 H, Harene, J = 6.3 Hz); 6.04 (br.s, 1 H, HN).
trans-η -(2-Methyl-1,4-dihydro-2Н-3,1-benzoxazine)tri-
6
η -(2,2-Dimethyl-1,4-dihydro-2Н-3,1-benzoxazine)tricarb-
carbonylchromium (trans-5e). HPLC: one peak,  = 5.3 min. UV
–
1
onylchromium (5b). HPLC: one peak, τ = 5.8 min. UV (МеCN,
(МеCN, H O), λ/nm: 216, 317, 432. IR (KBr), ν/cm : 3325
2
–
1
H O), λ/nm: 219, 317, 447. IR (KBr), ν/cm : 3402 (ν(N—H));
(ν(N—H)); 3099 (ν(Carene—Н)); 2991 (ν(C—H)); 1947,
2
2
946 (ν(C—H)); 1936, 1860, 1835 (ν(C≡O)); 1556, 1490
1859 (ν(C≡O)); 1558, 1530, 1489 (ν(Carene—C
)); 814,
arene
+
(
ν(Carene—Carene)); 750, 634 (ω(Carene—H)). MS, m/z (I (%)):
673 (ω(C
—H)). MS, m/z (I (%)): 285 [M] (67), 229
rel
arene
rel
+
+
+
+
+
+
2
1
99 [M] (33), 243 [M – 2 CO] (14), 215 [M – 3 CO] (100),
[M – 2 CO] (17), 201 [M – 3 CO] (100), 183 [M – 3 CO – H O]
2
+
+
(51), 168 [M – 3 CO – H O – Me] (60), 52 [Cr]+ (40).
+
97 [M – 3 CO – H O] (68), 182 [M – 3 CO – H O – Me]
2
2
2
+
1
1
(
59), 52 [Cr] (73). H NMR, : 1.37 (s, 3 Н, Me); 1.51 (s, 3 Н, Me);
H NMR, : 1.34 (d, 3 Н, Me, J = 5.9 Hz); 4.71 (d, 2 Н, OCH2,
4
4
.43 (d, 1 Н, ОCH , J = 14.9 Hz); 4.76 (d, 1 H, ОCH , J = 14.9 Hz);
J = 5.5 Hz); 4.82 (q, 1 Н, NCHO, J = 5.5 Hz); 5.09 (t, 1 Н,
Harene, J = 6.3 Hz); 5.21 (d, 1 Н, Harene, J = 7.0 Hz); 5.64 (td,
2
2
.96 (td, 1 H, Harene, J = 6.3 Hz, J = 0.8 Hz); 5.06 (dd, 1 H,
Harene, J = 6.7 Hz, J = 0.8 Hz); 5.64 (td, 1 H, Harene, J = 7.0 Hz,
J = 1.2 Hz); 5.84 (d, 1 H, Harene, J = 6.3 Hz); 6.20 (br.s, 1 H, HN).
1 Н, Harene, J = 7.0 Hz, J = 1.2 Hz); 5.73 (d, 1 Н, Harene,
J = 6.3 Hz); 6.10 (br.s, 1 Н, HN).
6
6
η -(2-Spirocyclohexane-1,4-dihydro-3,1-benzoxazine)tri-
cis-η -(2-Methyl-1,4-dihydro-2Н-3,1-benzoxazine)tricarb-
1
carbonylchromium (5c). HPLC: one peak, τ = 7.7 min. UV
onylchromium (cis-5e). H NMR, : 1.37 (d, 3 Н, Me, J = 5.5 Hz);
–
1
(
МеCN, H O), λ/nm: 219, 317, 446. IR (KBr), ν/cm : 3396
4.38 (d, 1 Н, OCH , J = 14.1 Hz); 4.73—4.80 (m, 2 Н, OCH ,
2
2
2
NCHO); 4.92 (td, 1 Н, Harene, J = 6.3 Hz, J = 0.8 Hz); 5.00 (dd, 1 Н,
Harene, J = 7.0 Hz, J = 0.8 Hz); 5.67 (td, 1 Н, Harene, J = 7.0 Hz,
J = 1.2 Hz); 5.87 (d, 1 Н, Harene, J = 6.3 Hz); 5.95 (br.s, 1 Н, HN).
Table 7. Reaction time () and temperature (T) of synthesis for
compounds 5a—k by methods A and B
6
trans-η -(2-Ethyl-1,4-dihydro-2Н-3,1-benzoxazine)tricarb-
onylchromium (trans-5f). HPLC: one peak, τ = 6.8 min. UV
–
1
(
(
1
6
[
(
–
МеCN, H O), λ/nm: 219, 318. IR (KBr), ν/cm : 3357
2
Com-
pound 5
/h
T/C
(В)
Com-
pound 5
/h
T/C
(В)
ν(N—H)); 3100 (ν(Carene—Н)); 2970 (ν(C—H)); 1941,
А
В
А
В
865 (ν(C≡O)); 1557, 1531, 1488 (ν(Carene—C
)); 814,
arene
+
73 (ω(C
—H)). MS, m/z (I (%)): 299 [М] (36), 243
arene
rel
a
b
c
d
e
f
4
4
6
4
5
6
5
8
8
8
9
7
25
40
40
40
40
50
g
h
i
j
k
5
5
4
5
4
8
7
8
7
6
50
50
80
50
40
+
+
+
М – 2 СО] (14), 215 [М – 3 СО] (40), 197 [M – 3 CO – H O]
2
+
52), 195 [M – 3 CO – H O – 2 H] (100), 168 [M – 3 CO –
2
+
+
1
H O – Et] (25), 52 [Cr] (81). H NMR, : 0.99 (t, 3 H, Me,
2
J = 7.8 Hz); 1.60—1.75 (m, 2 H, CH Me); 4.64 (t, 1 H, NCHO,
2
J = 5.1 Hz); 4.72 (s, 2 H, OCH ); 5.08 (td, 1 H, Harene, J = 6.3 Hz,
2
J = 0.8 Hz); 5.23 (dd, 1 H, Harene, J = 7.0 Hz, J = 0.8 Hz); 5.64

Dihydro-3,1-benzoxazines with Cr(CO) -group
Russ. Chem. Bull., Int. Ed., Vol. 70, No. 1, January, 2021
177
3
+
(
td, 1 H, Harene, J = 6.3 Hz, J = 1.2 Hz); 5.74 (br.d, 1 H, Harene
,
(85), 261 [M – 3 CO – 2 H]+ (100), 245 [M – 3 CO –H O]
2
+
J = 6.7 Hz); 6.05 (br.s, 1 H, HN).
(21), 243 [M – 3 CO – H O – 2 H] (50), 168 [M – 3 CO – H O
2
2
6
+
+
+
1
trans-η -(2-Butyl-1,4-dihydro-2Н-3,1-benzoxazine)tricarb-
onylchromium (trans-5g). HPLC: one peak, τ = 8.6 min. UV
– Ph] (6), 77 [Ph] (6), 52 [Cr] (21). H NMR, : 4.57 (d, 1 Н,
ОCH , J = 14.5 Hz); 4.98 (dd, 1 Н, Harene, J = 6.3 Hz, J = 0.8 Hz);
2
(
МеCN, H O), λ/nm: 219, 318 and 219, 318. IR (KBr),
5.03 (d, 1 H, ОCH , J = 14.5 Hz); 5.15 (d, 1 H, Harene,
2
2
–
1
ν/cm : 3374 (ν(N—H)); 3108 (ν(Carene—Н)); 2931 (ν(C—H));
J = 6.7 Hz); 5.63 (d, 1 H, NCHO, J = 2.7 Hz); 5.73 (td, 1 H, Harene,
1
6
962, 1894 (ν(C≡O)); 1555, 1525, 1485 (ν(Carene—Carene)); 862,
J = 7.0 Hz, J = 1.2 Hz); 5.95 (d, 1 H, Harene, J = 6.3 Hz); 6.12 (br.s,
+
71 (ω(C
—H)). MS (m/z (I (%)): 327 [М] (64), 271
1 H, HN); 7.37—7.46 (m, 3 H, HPh); 7.58—7.69 (m, 2 Н, HPh).
arene
rel
+
+
+
6
[
М – 2 СО] (15), 243 [М – 3 СО] (100), 225 [M – 3 CO – H O]
trans-η -[2-(2´-Furyl)-1,4-dihydro-2Н-3,1-benzoxazine]-
2
+
(
28), 223 [M – 3 CO – H O – 2 H] (68), 168 [M – 3 CO – H O
tricarbonylchromium (trans-5j). HPLC: one peak, τ = 6.1 min.
2
2
–
Bu] (65), 52 [Cr]+ (96). H NMR, : 0.90 (t, 3 H, Me,
+
1
UV (МеCN, H O), λ/nm: 219, 318. IR (KBr), ν/cm : 3360
–1
2
J = 7.4 Hz); 1.31—1.41, 1.41—1.52 (both m, 2 H each,
(ν(N—H)); 3099 (ν(Carene—Н)); 2865 (ν(C—H)); 1950,
Me(CH ) CH ); 1.67 (td, 2 H, Me(CH ) CH , J = 7.8 Hz,
1865, 1850 (ν(C≡O)); 1568, 1479 (ν(Carene—C
)); 741,
2
2
2
2 2
2
arene
+
J = 5.5 Hz); 4.69 (br.d, 1 H, NCHO, J = 5.5 Hz); 4.72 (s, 2 H,
673 (ω(Carene—H)). MS, m/z (Irel (%)): 337 [М] (39), 281
+
+
OCH ); 5.08 (td, 1 H, Harene, J = 6.3 Hz, J = 0.8 Hz); 5.23 (dd,
[М – 2 СО] (4), 253 [М – 3 СО] (79), 235 [M – 3 CO –
2
+
+
1
H, Harene, J = 7.0 Hz, J = 0.8 Hz); 5.64 (td, 1 H, Harene
,
– Н О] (67), 168 [M – 3 CO – Н О –C H O] (52), 52 [Cr]+
2 2 4 3
1
J = 7.0 Hz, J = 1.2 Hz); 5.74 (br.d, 1 H, Harene, J = 6.3 Hz);
(100). H NMR, : 4.64 (d, 1 H, ОCH , J = 14.5 Hz); 4.69
2
6
.04 (br.s, 1 H, HN).
(d, 1 H, ОCH , J = 14.5 Hz); 5.10 (td, 1 Н, Harene, J = 6.3 Hz,
2
6
cis-η -(2-Butyl-1,4-dihydro-2Н-3,1-benzoxazine)tricarb-
J = 0.8 Hz); 5.33 (dd, 1 H, Harene, J = 7.0 Hz, J = 0.8 Hz); 5.72
1
onylchromium (cis-5g). H NMR, : 0.90 (t, 3 H, Me, J = 7.4 Hz);
1
1
J = 14.1 Hz); 4.60—4.65 (m, 1 H, NCHO); 4.77 (d, 1 Н, OCH2,
J = 14.1 Hz); 4.93 (td, 1 H, Harene, J = 7.0 Hz, J = 0.8 Hz); 5.02
(td, 1 H, Harene, J = 6.3 Hz, J = 1.2 Hz); 5.82 (d, 1 Н, Harene,
.31—1.41, 1.41—1.52 (both m, 2 H each, Me(CH ) CH );
J = 6.3 Hz); 5.84 (d, 1 Н, NCHO, J = 2.7 Hz); 6.44—6.47 (m,
1 H, C H O); 6.50 (br.s, 1 H, HN); 6.54 (d, 1 Н, C H O,
2
2
2
.67—1.78 (m, 2 H, Me(CH ) CH ); 4.41 (d, 1 Н, OCH ,
2
2
2
2
4
3
4
3
J = 3.1 Hz); 7.60 (dd, 1 H, C H O, J = 2.0 Hz, J = 0.8 Hz).
4 3
6
cis-η -[2-(2´-Furyl)-1,4-dihydro-2Н-3,1-benzoxazine]tri-
1
(
dd, 1 H, Harene, J = 6.6 Hz, J = 0.8 Hz); 5.67 (td, 1 H, Harene
,
carbonylchromium (cis-5j). H NMR, : 4.52 (d, 1 H, ОCH2,
J = 7.4 Hz, J = 1.2 Hz); 5.86 (br.d, 1 H, Harene, J = 6.3 Hz);
J = 14.5 Hz); 4.96—5.02 (m, 2 Н, ОCH , Harene); 5.20 (br.d, 1 H,
2
5
.90 (br.s, 1 H, HN).
Harene, J = 6.7 Hz); 5.72—5.74 (m, 1 H, Harene); 5.77 (d, 1 Н,
6
trans-η -[2-(Prop-1´-en-1´-yl)-1,4-dihydro-2Н-3,1-benz-
NCHO, J = 3.1 Hz); 5.91 (br.d, 1 Н, Harene, J = 6.3 Hz); 6.30
oxazine]tricarbonylchromium (trans-5h). HPLC: one peak,
τ = 7.2 min. UV (МеCN, H O), λ/nm: 219, 318. IR (KBr), ν/cm
3
1
(br.s, 1 H, HN); 6.48 (dd, 1 H, C H O, J = 3.1 Hz, J = 1.6 Hz);
4 3
–1
:
6.69 (d, 1 H, C H O, J = 3.5 Hz); 7.59 (dd, 1 H, C H O,
2
4 3 4 3
J = 2.0 Hz, J = 0.8 Hz).
357 (ν(N—H)); 3100 (ν(Carene—Н)); 2971 (ν(C—H)); 1957,
865 (ν(C≡O)); 1531, 1488 (ν(Carene—Carene)); 814, 674
+
(
[
ω(Carene—H)). MS, m/z (I
(%)): 311 [М] (52), 255
rel
+
+
+
М – 2 СО] (8), 227 [М – 3 СО] (98), 209 [M – 3 CO – H O]
2
+
+
Table 8. Basic crystallographic data and structure refine-
ment statistics for compound cis-5i
(
100), 168 [M – 3 CO – H O – (СН) Me] (25), 52 [Cr] (52).
2 2
1
H NMR, : 1.72 (dd, 3 H, Me, J = 6.3 Hz, J = 1.2 Hz); 4.71
d, 2 H, OCH , J = 2.0 Hz); 5.05—5.12 (m, 2 H, NCHO, Harene);
(
5
(
(
6
2
.27 (dd, 1 H, Harene, J = 7.0 Hz, J = 0.8 Hz); 5.48—5.59 (m, 1 H,
Parameter
Value
СН) Me); 5.66 (td, 1 H, Harene, J = 7.0 Hz, J = 1.2 Hz); 5.75
2
Molecular formula
C17H13CrNO4
347.28
P2(1)/c
11.9124(10)
8.3651(8)
15.5815(12)
90
103.043(8)
90
1512.6(2)
4
d, 1 H, Harene, J = 6.7 Hz); 5.90—6.02 (m, 1 H, (СН) Me);
2
Molecular weight
Space group
a/Å
.07 (br.s, 1 H, HN).
6
trans-η -(2-Phenyl-1,4-dihydro-2Н-3,1-benzoxazine)tricarb-
onylchromium (trans-5i). HPLC: one peak, τ = 6.2 min. UV
b/Å
c/Å
(
[
[
[
(
(
МеCN, H O), λ/nm: 218, 318, 430. MS, m/z (I (%)): 347
2
r
e
l
+
+
+
M] (36), 291 [M – 2 CO] (5), 263 [M – 3 CO] (76), 261
α/deg
+
+
M – 3 CO – 2 H] (100), 245 [M – 3 CO – H O] (28), 243
2
β/deg
+
+
+
M – 3 CO –H O – 2 H] (67), 168 [M – 3 CO – H O – Ph]
2
2
γ/deg
12), 157 [M – 3 CO – PhCHO] (6), 77 [Ph]+ (32), 52 [Cr]
+
3
V/Å
Z
55). IR (KBr), ν/cm– : 3327 (ν(N—H)); 2925 (ν(C—H)); 1967,
1
1
6
874 (ν(C≡O)); 1549, 1525, 1477 (ν(Carene—Carene)); 780, 710,
61 (ω(Carene—H)). H NMR, : 4.78 (d, 1 H, ОCH2,
–3
dcalc/mg m
1.525
0.776
3.447—26.372
1
–1
μ/mm
J = 14.5 Hz); 4.87 (d, 1 H, ОCH , J = 14.5 Hz); 5.14 (td, 1 Н,
2

-Range for data collection/deg
Harene, J = 6.3 Hz, J = 0.8 Hz); 5.36 (dd, 1 H, Harene, J = 6.7 Hz,
J = 0.8 Hz); 5.68—5.74 (m, 2 Н, Harene, NCHO); 5.82 (d, 1 Н,
Harene, J = 6.3 Hz); 6.31 (br.s, 1 H, HN); 7.38—7.47 (m, 3 Н,
HPh); 7.48—7.56 (m, 2 Н, HPh).
Number of reflections
collected
21489
2276
unique with I > 2σ(I)
Rint
0.0721
6
cis-η -(2-Phenyl-1,4-dihydro-2Н-3,1-benzoxazine)tricarb-
2
GOOF (F )
1.044
onylchromium (cis-5i). HPLC: one peak, τ = 5.8 min. UV (МеCN,
H O), λ/nm: 216, 320, 431. IR (KBr), ν/cm : 3410 (ν(N—H));
2
(
(
R (I > 2σ(I))
0.0475
–
1
1
2
ωR ( all data)
0.139
2
916 (ν(C—H)); 1947, 1869, 1844 (ν(C≡O)); 1652, 1558
Residual electron density
–0.399/0.353
ν(Carene—Carene)); 750, 710, 670 (ω(C
—H)). MS, m/z
arene
–3
(
min/max)/е Å
Irel (%)): 347 [M]+ (19), 291 [M – 2 CO]+ (5), 263 [M – 3 CO]
+

1
78
Russ. Chem. Bull., Int. Ed., Vol. 70, No. 1, January, 2021
Sazonova et al.
6
trans-η -[2-(2´-Pyridyl)-1,4-dihydro-2Н-3,1-benzoxazine]-
6. M. Rosillo, G. Domínguez, J. Perez-Castells, Chem. Soc.
Rev., 2007, 36, 1589.
7. Transition Metal Arene π-Complexes in Organic Synthesis and
Catalysts, Ed. E. P. Kündig, in Topics in Organometallic
Chemistry, 7, Springer, 2004.
8. C. Mukai, I. J. Kim, W. J. Cho, M. Kido, M. Hanaoka,
J. Chem. Soc., Perkin Trans. 1, 1993, 2495.
9. A. R. Pape, K. P. Kaliappan, E. P. Kündig, Chem. Rev., 2000,
100, 2917.
10. A. N. Artemov, E. V. Sazonova, E. A. Mavrina, N. Yu.
Zarovkina, Russ. Chem. Bull., 2012, 61, 2076.
11. A. N. Artemov, E. V. Sazonova, N. Yu. Zarovkina, Russ.
Chem. Bull., 2013, 62, 1382.
12. N. Yu. Zarovkina, E. V. Sazonova, A. N. Artemov, G. K. Fukin,
Russ. Chem. Bull., 2014, 63, 970.
tricarbonylchromium (trans-5k). HPLC: one peak, τ = 6.1 min.
–
1
UV (МеCN, H O), λ/nm: 218, 319, 432. IR (KBr), ν/cm
:
2
3
1
6
234 (ν(N—H)); 3096 (ν(Carene—Н)); 2922 (ν(C—H)); 1947,
881, 1854 (ν(C≡O)); 1557, 1530, 1500 (ν(Carene—Carene)); 788,
+
77 (ω(Carene—H)). MS, m/z (I (%)): 348 [M] (15), 347
rel
+
+
+
[
M – Н] (21), 292 [M – 2 CO] (7), 264 [M – 3 CO] (100),
+
+
2
46 [M – 3 CO – Н О] (63), 168 [M – 3 CO – Н О – С Н N]
2
2
5
4
+
1
(
43), 52 [Cr] (17). H NMR, : 4.90 (d, 1 H, OCH , J = 14.5 Hz);
2
4
.98 (d, 1 H, OCH , J = 14.5 Hz); 5.15 (t, 1 H, Harene,
2
J = 6.3 Hz); 5.56 (d, 1 H, Harene, J = 6.7 Hz); 5.72 (td, 1 H,
Harene, J = 7.0 Hz, J = 1.2 Hz); 5.75 (s, 1 H, NCHO); 5.81 (d,
1
H, Harene, J = 6.3 Hz); 6.52 (br.s, 1 H, H ); 7.41 (ddd, 1 H,
N
Hpy, J = 5.5 Hz, J = 4.7 Hz, J = 0.8 Hz); 7.64 (d, 1 H, Hpy
,
J = 7.8 Hz); 7.90 (td, 1 H, Hpy, J = 7.8 Hz, J = 1.6 Hz); 8.57
(
br.dd, 1 H, Hpy, J = 4.7 Hz, J = 0.8 Hz).
13. N. Yu. Zarovkina, E. V. Sazonova, A. N. Artemov, G. K. Fukin,
Russ. Chem. Bull., 2015, 64, 923.
X-ray diffraction study of complex cis-5i. Single crystals of
compound cis-5i were obtained by crystallization from a mixture
of hexane—ethyl acetate (4 : 1). The X-ray diffraction experiment
was carried out on an Oxford Diffraction Gemini S diffracto-
meter (graphite monochromator, λ(Mo-Кα) = 0.71073 Å,
temperature 297(2) K, ω-scan technique). The crystallographic
data and the main refinement parameters for compound cis-5i
14. N. Yu. Grishina, E. V. Sazonova, A. N. Artemov, G. K. Fukin,
V. I. Faerman, Russ. Chem. Bull., 2017, 66, 313.
15. A. N. Artemov, E. V. Sazonova, N. A. Krylova, E. A. Zvereva,
N. A. Pechen, G. K. Fukin, A. V. Cherkasov, V. I. Faerman,
N. Yu. Grishina, Russ. Chem. Bull., 2018, 67, 884.
16. A. N. Artemov, E. V. Sazonova, N. A. Aksenova, G. K. Fukin,
A. V. Cherkasov, V. I. Faerman, N. Yu. Grishina, Russ. Chem.
Bull., 2019, 68, 1548.
17. L. Peng, Z. Liu, J. Wang, L. Wu, Tetrahedron Lett., 2007, 48, 7418.
18. F. W. Holly, A. C. Cope, J. Am. Chem. Soc., 1944, 66, 1875.
19. H. Surburg, M. Gürtert, B. Schwarze, J. Essential Oil
Research, 1990, 2, 307.
20. H. V. Mierde, P. V. D. Voort, F. Verpoort, Tetrahedron Lett.,
2009, 50, 201.
21. F. I. Zubkov, E. V. Nikitina, T. R. Galeev, V. P. Zaytsev, V. N.
Khrustalev, R. A. Novikov, D. N. Orlova, A. V. Varlamov,
Tetrahedron, 2014, 70, 1659.
3
2
are given in Table 8. Analytical correction for absorption. The
primary fragment of the structure was found by direct methods.
Parameters of the remaining atoms, including hydrogen atoms,
were determined from the difference synthesis of the electron
2
density and refined by the least-squares method based on F hkl.
The positions of hydrogen atoms were refined in the main cycle
of the least squares method in the isotropic approximation. All
calculations were performed using the SHELX33 and WinGX
software package. The structure cis-5i was deposited with the
Cambridge Crystallographic Data Center (CCDC 1986599) and
is available at ccdc.cam.ac.uk/structures.
34
2
2. F. Fülöp, M. Dahlqvist, K. Pihlaja, Acta Chem. Scand., 1991,
45, 273.
The authors are grateful to the staff of the Chemical
Department of the Lobachevsky State University of
Nizhny Novgorod T. I. Liogon´kaya for the registration
of IR spectra and Yu. B. Malysheva for the registration of
23. W. E. Silverthorn, Adv. Organomet. Chem., 1975, 13, 47.
2
4. K. H. Pannel, B. L. Kalsotra, C. Parkanyil, J. Heterocycl.
Chem., 1978, 15, 1057.
1
25. G. K. Fukin, A. V. Cherkasov, E. V. Baranov, R. V. Rumyantcev,
H NMR spectra.
E. V. Sazonova, A. N. Artemov, Chem. Select., 2019, 4, 10976.
This work was financially supported by the Ministry of
Science and Higher Education of the Russian Federation
2
6. G. K. Fukin, A. V. Cherkasov, R. V. Rumyantcev, N. Yu.
Grishina, E. V. Sazonova, A. N. Artemov, A. I. Stash,
Mendeleev Commun., 2019, 29, 346.
(
Project No. 0729-2020-0039) in the framework of the
Basic part of the Russian state assignment.
27. L. J. Farrugia, C. Evans, D. Lentz, M. Roemer, J. Am. Chem.
Soc., 2009, 131, 1251.
2
2
8. J. Müller, P. Göser, Chem. Ber., 1969, 102, 3314.
9. E. V. Gromachevskaya, F. V. Kvitkovskii, T. P. Kosulina,
V. G. Kul´nevich, Сhem. Heterocycl. Compd., 2003, 39, 137.
0. A. Weissberger, E. Proskauer, J. A. Riddick, E. E. Toops, Jr.,
Organic Solvents; Physical Properties and Methods of Purifi-
cation, Intersci. Publ. Inc., New York—London, 1955, 552 pp.
References
1
. L. I. Kasyan, V. A. Pal´chikov, A. V. Tokar´, Oksaazagetero-
3
tsikly na osnove aminospirtov, epoksidov i aziridinov [Oxa-
azaheterocycles Based on Amino Alcohols, epoxides, and Azirid-
ines], DNU, Dnepropetrovsk, 2012, 644 pp. (in Russian).
. D. I. Bugaenko, A. V. Karchava, M. A. Yurovskaya, Russ.
Chem. Rev., 2018, 87, 272.
31. M. D. Rausch, G. A. Moser, E. S. Zaiko, A. L. Lipman,
2
3
4
5
J. Organomet. Chem., 1970, 23, 185.
3
3
3
2. R. C. Clark, J. S. Reid, Acta Crystallogr., Sect. A, 1995, 51, 887.
3. G. M. Sheldrick, Acta Crystallogr., Sect. C, 2015, 71, 3.
4. L. J. Farrugia, J. Appl. Crystallogr., 1999, 32, 837.
. Bioorganometallics: Biomolecules, Labeling, Medicine, Ed.
G. Jaouen, Willey-VCH, 2005, 444 pp.
. A. Berger, J. P. Djukic, Ch. Michon, Coord. Chem. Rev., 2002,
2
25, 215.
. M. F. Semmelhack, in Comprehensive Organometallic Chem-
istry II, Eds E. W. Abel, F. G. A. Stone, G. Wilkinson,
Pergamon Press, Oxford, UK, 1995, 12, 1017.
Received May 18, 2020;
in revised form August 27, 2020;
accepted October 7, 2020