Reaction of Push-Pull Enaminoketones and in Situ Generated ortho-Quinone Methides: Synthesis of 3-Acyl-4H-chromenes and 2-Acyl-1H-benzo[f]chromenes as Precursors for Hydroxybenzylated Heterocycles

Article abstract of DOI:10.1021/acs.joc.6b02716

A simple and efficient method for the synthesis of 4H-chromenes and 1H-benzo[f]chromenes containing a trifluoroacetyl or aroyl group in the pyran ring from o-quinone methide precursors and push-pull enaminoketones has been developed. The chromenes are presumably formed through an initial oxa-Diels-Alder reaction, followed by an elimination of amine. The possibility of further transformations of given chromenes to o-hydroxybenzylated pyrazoles, isoxazoles, and pyridines has been demonstrated.

Full text of DOI:10.1021/acs.joc.6b02716

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Article
Reaction of Push-pull Enaminoketones and in situ Generated ortho-
Quinone Methides: Synthesis of 3-Acyl-4H-chromenes and 2-Acyl-1H-
benzo[f]chromenes as Precursors for Hydroxybenzylated Heterocycles
Anton Vladimirovich Lukashenko, Vitaly Aleksandrovich
Osyanin, Dmitry Vladimirovich Osipov, and Yuri N. Klimochkin
J. Org. Chem., Just Accepted Manuscript • DOI: 10.1021/acs.joc.6b02716 • Publication Date (Web): 16 Jan 2017
Downloaded from http://pubs.acs.org on January 16, 2017
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Reaction of Push-pull Enaminoketones and in situ Generated ortho-Quinone
Methides: Synthesis of 3-Acyl-4H-chromenes and 2-Acyl-1H-
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benzo[f]chromenes as Precursors for Hydroxybenzylated Heterocycles
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Anton V. Lukashenko,a Vitaly A. Osyanin,*a,b
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Dmitry V. Osipov,a Yuri N. Klimochkina
a Department of Organic Chemistry, Chemical Technological Faculty, Samara State Technical University, 244
Molodogvardeyskaya St., Samara 443100, Russian Federation.
b Organic Chemistry Department, Faculty of Science, RUDN University, 6 MiklukhoꢀMaklaya St., Moscow 117198,
Russian Federation.
Fax +7(846)3322122; Eꢀmail: vosyanin@mail.ru
ABSTRACT: A simple and efficient method for the synthesis of 4Hꢀchromenes and 1Hꢀ
benzo[f]chromenes containing trifluoroacetyl or aroyl group in pyran ring from oꢀquinone
methide precursors and pushꢀpull enaminoketones has been developed. The chromenes are
presumably formed through an initial oxaꢀDielsꢀAlder reaction followed by an elimination of
amine. Possibility of further transformations of given chromenes to oꢀhydroxybenzylated
pyrazoles, isoxazoles and pyridines has been demonstrated.
Key words oꢀquinone methide, pushꢀpull olefin, DielsꢀAlder reaction, 4Hꢀchromene, 1Hꢀ
benzo[f]chromene, enaminoketone.
INTRODUCTION
Pushꢀpull olefins, which are compounds containing electronꢀdonating groups and electronꢀ
withdrawing groups at the opposite ends of a double bond, have attracted considerable attention
due to their unusual physicochemical properties, such as high stability, easy E/Zꢀisomerization,
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significant charge transfer, that make them suitable for both nucleophilic and electrophilic
attack.1 Such compounds are very useful building blocks and widely used in organic synthesis.2
βꢀEnaminones that combine the ambident nucleophilicity of enamines with the ambident
electrophilicity of enones fall into this pushꢀpull category. The carbonyl group, conjugated to the
enamine moiety, gives this high reactive system enough stability to be easily prepared, isolated
and stored under atmospheric conditions at room temperature. Owing to this, they have found
numerous applications on the field of the heterocyclic chemistry.3 At the same time, their
reactions as dienophiles with polarized dienes or heterodienes remain little known,4 although
pushꢀpull nature of the double bond might make them potentially excellent partners in Dielsꢀ
Alder reaction. We assumed that highly polarized oꢀquinone methides (oꢀQMs), which, similar
to pushꢀpull olefins, are ambiphilic reagents,5 would react with such olefins through an additionꢀ
elimination mechanism to form 4Hꢀchromene derivatives.
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4HꢀChromene skeleton constitutes a key structural element in many biologically active
compounds, primarily anticancer agents.6 In contrast to 2Hꢀchromenes,7 the 4Hꢀchromenes as a
class of natural products are rather unusual. Some examples of naturally occurring 4Hꢀ
chromenes including chromenes bearing carbonyl group at Cꢀ3 position of the pyran ring are
presented (Figure 1).8 Among them there are phytoestrogens miroestrol and deoxymiroestrol,8d
antibiotic rhodomyrtone,8e,f antimicrobial acylphloroglucinols callistenone A8g and tomentosone
C,8h uvafzelic acid8i and others.
Figure 1. Selection of Natural Products Containing 4H-Chromene Rings
Comprehensive literature survey discloses that many efforts were made towards the
synthesis of 3ꢀacyl substituted 4Hꢀchromenes. A number of methods for their preparation have
been developed, such as coupling of benzylic alcohols with ketene dithioacetals,9 cycloaddition
of enamines to oꢀQM precursors,4a,10 Michael addition of Cꢀnucleophiles to 2ꢀ(1ꢀ
tosylalkyl)phenols,11 reactions of oꢀhalogenobenzyl bromides or oꢀhydroxybenzyl alcohols with
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1,3ꢀdicarbonyl compounds,12 reaction of phenol and naphthol Mannich bases with
aryl(ethynyl)ketones,13 threeꢀcomponent condensation of 1,3ꢀdiketones, 2ꢀnaphthol and aromatic
aldehydes,14 Me3SiIꢀpromoted reaction of salicylic aldehydes with βꢀdiketones15 and aluminum
triflate catalyzed acylation of bridge benzopyrans.16 4ꢀSubstituted 3ꢀacetylchromenes were
prepared from salicylic aldehydes or salicyl Nꢀtosylimines and acetylenic ketones.17 It should be
noted that most of these methods involve the use of 1,3ꢀdicarbonyl compounds or their synthetic
equivalents, whereby the resulting acylchromenes have substituents at the 2ꢀ and/or 4ꢀposition of
the pyran ring. This fact limits the range of possible further reactions involving them. At the
same time, the presence of electronꢀwithdrawing acyl substituent in the pyran fragment increases
the reactivity of double bond C(2)=C(3) conjugated with a carbonyl group with regard to
nucleophiles, and for this reason 3ꢀacylꢀ4Hꢀchromenes and 2ꢀacylꢀ1Hꢀbenzo[f]chromenes are
valuable substrates for the preparation of more complex heterocycles.
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oꢀQMs are highly reactive intermediates and their utility for preparation of various fused
pyran derivatives, common scaffolds in natural products, has recently gained considerable
interest.18 Since the oꢀQMs are inverse electron demand dienes, most of the dienophiles
employed have been electron rich. Dienophiles such as ketene acetals, vinyl ethers and vinyl
sulfides readily participate in the [4+2]ꢀcycloaddition with oꢀQM.19 However, the use of large
excesses of 2π partners are often required for efficient cycloaddition.20 The DielsꢀAlder reaction
of oꢀOMs with olefins substituted with mildly electronꢀreleasing (alkyl) or electronꢀaccepting
substituents does not occur readily.21 Their reactions with pushꢀpull olefins also remain little
known.4,22 In continuation of our interest in oꢀQM chemistry, we now report a novel route for the
synthesis of electron deficient 3ꢀacylꢀ4Hꢀchromenes and 2ꢀacylꢀ1Hꢀbenzo[f]chromenes from
pushꢀpull enaminoketones and oꢀQM precursors.
RESULTS AND DISCUSSION
We first investigated the reaction between the 2ꢀnaphthol Mannich base 1a and 1,1,1ꢀtrifluroꢀ4ꢀ
morpholinobutꢀ3ꢀenꢀ2ꢀone 2a in different solvents under reflux. The results showed that the
reaction can be performed in acetic or propionic anhydride, or acetic acid, which afforded the
highest yield. The reaction could also proceed in other solvents, such as DMF and oꢀxylene, but
the yields of 1Hꢀbenzo[f]chromene 3a were low. In 1,4ꢀdioxane, acetonitrile and BF3·Et2O the
reaction did not proceed (Table 1). Attempts to improve the yield by increasing the reaction time
o
were unsuccessful. We observed only starting materials in acetic acid at 80 C after 3 h.
Moreover, the reaction with equimolar amount of acetic acid or acetic anhydride in 1,4ꢀdioxane
or oꢀxylene under reflux led to formation of chromene 3a with low yield. Thus, the choice of
solvent for the preparation of 3a is critical. The reaction was repeated on several different scales
(up to 50 mmol), all with comparable yields using the optimal conditions.
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Table 1. Effect of Solvent and Time on the Synthesis of 3aa
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solvent
time, h
yield of 3a, %
Ac2O
3
1
56
75
76
74
ꢀ
AcOH
AcOH
AcOH
AcOHb
2
3
3
1,4ꢀdioxane
5
ꢀ
1,4ꢀdioxane (1 eq AcOH)
1,4ꢀdioxane (1 eq Ac2O)
(EtCO)2O
5
12
19
55
56
15
17
17
-
3
0.5
1
(EtCO)2O
DMF
3
oꢀxylene
5
oꢀxylene (1 eq AcOH)
BF3·Et2O
3
5
MeCN
10
-
aReaction conditions: Mannich base 1a (1 mmol) and enaminone 2a
(1 mmol) in solvent (5 mL) under reflux. bReaction was performed at
80 oC.
A mechanistic rationale portraying the probable sequence of events is given in Scheme 1.
We suppose that the reaction proceeds via the oꢀQM intermediate A, which is formed by the
thermal desamination of the Mannich base 1a. Subsequent cycloaddition of the oꢀQMs with
enaminone 2a affords the unstable benzochroman cycloadduct B which is desaminated to give
1Hꢀbenzo[f]chromene derivative 3a. The driving force of the cycloaddition is the resulting
rearomatization of the benzene ring.23 In this reaction the oꢀQM reacts as electronꢀdeficient
heterodiene. Its reaction with pushꢀpull enamine proceeds regioselectively in a way that the
carbon connected with morpholine fragment reacts with the oꢀQM oxygen, and the neighbouring
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vinylic carbon with the methylene carbon of the oꢀQM. The regioselectivity can be readily
explained by ionic resonance forms of the coreactants.
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Scheme 1. Proposed Mechanism for the Synthesis of 3a
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AcOH plays two roles in the reaction: activating the Mannich base to generate oꢀQM, and
catalysing the elimination of morpholine from cycloadduct to give chromene. Besides, evolving
morpholine and dimethylamine are converted into corresponding amides. Because the
morpholine is sequestered, a potential side reaction, namely conjugated addition of morpholine
to the oꢀQM intermediate to give Mannich base 4, is prevented. In oꢀxylene and DMF, the
reaction was very sluggish and complicated mixture of products, including the expected
benzochromene 3a as well as Mannich base 4, enaminoketone 2b and 3ꢀ(trifluoromethyl)ꢀ2,3ꢀ
dihydroꢀ1Hꢀbenzo[f]chromenꢀ3ꢀol 5 was obtained (Scheme 2). The proposed mechanism for the
formation of chromenol 5 includes the following steps: retroꢀoxaꢀMichael reaction – opening of
dihydropyran ring in the intermediate B, azaꢀMichael addition of secondary amines (morpholine
or dimethylamine), a retroꢀMannich reaction and intramolecular addition at the carbonyl group
(hemiketalization). The product 2b is a result of nucleophilic vinylic substitution (SN Vin).24
Scheme 2. Reaction of 1a and 2a in o-Xylene or DMF
O
CF3
O
CF3
OH
NMe2
OH
O
N
O
o-xylene
F3C
N
O
+
O
+
+
+
NMe2
OH
F3C
or DMF
O
2a
2b
1a
3a
5
4
CF3
H+
CF3
O
H
O
O
CF3
O
CF3
OH
O
O
O
CF3
O
O
N
N
N
R2NH
NR2
O
OH
5
OH
R2NH = morpholine
or Me2NH
N+ NR2
B
O
Under the optimized reaction conditions, the scope and generality of this reaction were
then explored. A variety of electronically divergent oꢀQM precursors were examined, and the
results are summarized in Table 2. The reactions were carried out until complete conversion of
enaminone. Products can be easily purified from impurities by single recrystallization. The
method turned out to be tolerant toward a broad range of functional groups. The reaction
proceeded without any problems for a wide range of substrates bearing electronꢀdonating (Alk,
MeO) or electronꢀwithdrawing (Hal, NO2, CN) substituents on the aryl ring and naphthalene
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fragment, providing the corresponding benzochromenes 3b–o in moderate to good yields. The
sterically hindered tertꢀbutylꢀsubstituted chromene 3n was obtained in good yield, indicating that
steric hindrance had no obvious influence on the efficiency of this method. This reaction was
also extended to heterocyclic precursor 1o of oꢀQM. From 5ꢀ((dimethylamino)methyl)ꢀ6ꢀ
hydroxyꢀ2,3,4,9ꢀtetrahydroꢀ1Hꢀpyrido[3,4ꢀb]indolꢀ1ꢀone 1o and enaminone 2a a novel
heterocyclic system 7,9,10,11ꢀtetrahydropyrano[3,2ꢀe]pyrido[3,4ꢀb]indolꢀ8(1H)ꢀone 3o was
prepared in 45% yield.
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Table 2 Preparation of 2-Trifluoroacetyl-1H-benzo[f]chromenes 3b–oa
F
O
CF3
O
3f, 65%
O
CF3
O
3m, 67%
Ph3C
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aReaction conditions: Mannich base 1b–o (1.45 mmol) and enaminone 2a (1.45 mmol) in acetic
acid (5 mL) under reflux for 1 h (3b,c,h–n) or 3 h (3d–g,o).
In the case of 1ꢀunsubstituted Mannich bases the reaction can also be carried out in Ac2O
under reflux. At the same time, in the case of naphthol Mannich bases bearing aryl substituent at
the 1ꢀposition using of acetic anhydride as a solvent afforded diacetates 6a and 6b as a result of
addition of acetic acid to oꢀQM followed by Oꢀacetylation of 2ꢀnaphthol hydroxyl group
(Scheme 3).
Scheme 3. Reaction of Mannich Bases 1b and 1e with Acetic Anhydride
Having successfully applied the 'Mannich route' to the synthesis based on the oꢀ
naphthoquinone methides, it was of interest to see if we might be successful in applying the
synthesis to oꢀbenzoquinone methides. Attempts to extend this reaction to the Mannich bases of
simple phenols, however, failed to furnish the expected products. The reason for the failure may
be due to the relatively greater thermal stability of the oꢀphenolic Mannich bases compared to
that of the 2ꢀnaphthol derivatives and consequent difficulty in generating the oꢀQMs.
Nevertheless, in the reaction with quaternary ammonium salts 7a–d which are more reactive
precursors of the oꢀQMs corresponding 4Hꢀchromene derivatives 8a–d were prepared in
moderate to good yields (Table 3).
Table 3. Preparation of 3-Trifluoroacetyl-4H-chromenes 8a–da
Entry Quaternary ammonium salt 7
Product 8
1
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4
aReaction conditions: quaternary ammonium salt 7a–d (1.45 mmol) and
enaminone 2a (1.45 mmol) in acetic acid (5 mL) under reflux.
The new compounds 8 can be considered as useful trifluoromethylꢀcontaining substrates
for the synthesis of a variety of heterocyclic compounds with potential biological activity.
Besides, introduction of such powerful electronꢀwithdrawing group as trifluoroacetyl in the 2ꢀ
position of the 1Hꢀbenzo[f]chromenes or in the 3ꢀposition of the 4Hꢀchromenes increases their
reactivity toward nucleophilic reagents and opens up a broad synthetic scope of these
heterocyclic systems.24
In the next step, variation of the acyl groups was studied and a number of 2ꢀaroylꢀ1Hꢀ
benzo[f]chromenes 10a–o was synthesized from aroylenamines 9a–e and 2ꢀnaphthol Mannich
bases using the optimal reaction conditions (Table 4). The electronic properties of the R1 and R2
substituents have little effect on the yield.
Table 4. Preparation of 2-Aroyl-1H-benzo[f]chromenes 10a–oa
entry Mannich base R1
enaminone R2
product yield, %
1
2
H
H
H
75
80
1a
1b
9a
9a
10a
10b
Ph
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3
mꢀNO2C6H4
pꢀMeOC6H4
H
H
64
85
68
75
60
70
74
73
65
69
68
68
85
1d
1p
1a
1b
1d
1p
1a
1b
1d
1p
1b
1p
1q
9a
9a
9b
9c
9c
9c
9d
9d
9d
9d
9e
9e
9a
10c
10d
10e
10f
4
H
5
oꢀHO
pꢀMe
pꢀMe
pꢀMe
pꢀCl
pꢀCl
pꢀCl
pꢀCl
pꢀMeO
pꢀMeO
H
6
Ph
7
mꢀNO2C6H4
pꢀMeOC6H4
H
10g
10h
10i
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8
9
10
11
12
13
14
15
Ph
10j
mꢀNO2C6H4
pꢀMeOC6H4
Ph
10k
10l
10m
10n
10o
pꢀMeOC6H4
1ꢀbenzylꢀ1Hꢀ
imidazolꢀ5ꢀyl
aReaction conditions: Mannich base 1 (1.45 mmol) and enaminone 9 (1.45 mmol) in
acetic acid (5 mL) under reflux for 1 h.
Although aroylenamines are not stable under acidic reaction conditions and easily undergo
trimerization to give 1,3,5ꢀtriaroylbenzenes,25 we have observed such byꢀproduct 11 only in the
case of enaminone 9e (Scheme 4).
Scheme 4. AcOH-catalysed Trimerization of Enaminone 9e
OMe
O
O
O
MeO
AcOH
1 h
O
9e
NMe2
O
MeO
MeO
O
Me2N
OMe
9e
11
OMe
The generation of oꢀQM via thermolytic extrusion of H2O from salicylic alcohols is widely
used for preparation of fused heterocycles. These reactions are often performed in refluxing
DMF or under solventꢀfree conditions, at sufficiently high temperature to ensure the thermal
decomposition of the oꢀQM precursors.26 In our case, however, the reaction between salicylic
alcohols and enaminone 9a in refluxing DMF does not take place. At the same time, 3ꢀbenzoylꢀ
4Hꢀchromenes 13a–d were obtained in 48–66% yields by heating salicylic alcohols 12a–d and
enaminone 9a in acetic anhydride (Table 5). Reaction also takes place with equimolar amount of
acetic anhydride in refluxing oꢀxylene with comparable yield. However, no product was
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observed in the mixture of 1,4ꢀdioxane and 1 equivalent of acetic anhydride. These facts can be
explained by the transformation of oꢀhydroxybenzyl alcohols in acetates27 which are more
reactive precursors of oꢀQMs (Scheme 5), but refluxing temperature of 1,4ꢀdioxane is not
sufficient. The enhanced reactivity allows the reactions to proceed to completion without the
need for an excess of dienophile, thus simplifying greatly the workꢀup procedure.
Table 5. Preparation of 3-Benzoyl-4H-chromenes 13a–da
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entry 2ꢀhydroxybenzyl
alcohol
R1
R2
R3
product yield, %
1
Ph
H
H
H
66 (67)b
12a
13a
2
3
4
Me
H
1ꢀAd
OMe
Br
49
50
48
12b
12c
12d
13b
13c
13d
H
H
1ꢀAd
aReaction conditions: 2ꢀhydroxybenzyl alcohol 12 (2 mmol) and enaminone 9a (2 mmol)
b
in acetic anhydride (4 mL) under reflux for 2 h. Reaction was performed in oꢀxylene
under reflux for 3 h with 1 eq of Ac2O.
Scheme 5. Activation of Salicylic Alcohols in Acetic Anhydride
O
O
OH
OH
Ac2O
H
OAc
- AcOH
- AcOH
Structural assignment was based on elemental analyses and absence of an OHꢀband in the
1
IR and of the phenolic proton signal in the H NMR spectra of the chromene derivatives,
respectively. In the IR spectra of compounds 3a–o and 8a–d there were strong absorption bands
corresponding to the vibrations of the carbonyl group in the region of 1681–1708 cm–1 and pyran
C=C double bond at 1627–1655 cm–1. 13C NMR spectra of compounds 3a–o and 8a–d showed
the carbon atom of trifluoromethyl group and the adjacent carbonyl carbon atom as quartets at
1
2
116.4–116.8 ppm with JC–F = 288.9–290.0 Hz and at 178.5–179.6 ppm with JC–F = 34.3–35.6
Hz, respectively. The carbon atom of the carbonyl group of aroylchromenes 10 and 13 except the
compound 10e (δ = 180.2 ppm) resonated at 193.1–195.6 ppm. The signals for the atoms Cꢀ3
(1Hꢀbenzo[f]chromenes) and Cꢀ2 (4Hꢀchromenes) in the 13C NMR spectra are found at 150.8–
1
156.6 ppm. In the H NMR spectra, protons attached to these carbon atoms appeared in the
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region of 7–8 ppm. The number of protons that were directly linked to 13C atoms, inferred from
DEPT spectra, was in accordance with the presented structures.
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Having established a strategy for the synthesis of acylchromenes, the applicability of these
structures was studied. The introduction of the electronꢀwithdrawing group at the C2 position of
the 1Hꢀbenzo[f]chromene system changes the reactivity of the pyran ring with respect to
nucleophiles. The diversity of properties of these compounds comes from the fact that they are
highly reactive pushꢀpull olefins with a good leaving group at the βꢀcarbon atom. The role of this
group is played by the phenolate anion. On the other hand, they can be considered as masked αꢀ
hydroxybenzyl αꢀformylketones. Heterocyclic moieties such as pyridine, pyrazole and isoxazole
based structures 14–16 were obtained treating the 1Hꢀbenzo[f]chromene 3a and 10a with the
appropriate Cꢀ and Nꢀnucleophiles (Scheme 6).
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Scheme 6. Heterocyclic Compounds Obtained from 1H-benzo[f]chromenes 3a and 10a
NH2
CF3
NH
O
NC
CF3
NH
CH2(CN)2
S
R
DABCO, MeCN
DABCO, MeCN
OH
14a
O
O
OH
S
CN
3a, 10a
CN
NH2OH, MeOH
.
N2H4 H2O
14b
R
Ph
N
NH
O
N
OH
OH
R = CF3 (15a), Ph (15b)
16
CONCLUSION
We have developed a facile protocol for the synthesis of 2ꢀacylꢀ1Hꢀbenzo[f]chromenes and 3ꢀ
acylꢀ4Hꢀchromenes based on cascade oxaꢀDielsꢀAlder and elimination reactions. Their synthesis
by the suggested procedure does not require an excess of any reagents and the use of any
catalysts. Besides, the advantages of this method include the use of available reagents, simple
workup procedure, easy isolation, scalability and good functional group tolerance.
EXPERIMENTAL SECTION
1
Materials and Characterization. FTIR spectra were taken in KBr pellets. H, 13C, and
DEPT NMR spectra were recorded using a 400 MHz NMR spectrometer in CDCl3, DMSOꢀd6,
or CD3CN solutions, relative to residual solvent signal. Chemical shifts and coupling constants
were recorded in units of parts per million and hertz, respectively. The melting points were
determined by capillary method and uncorrected. Elemental analysis was carried out on an
automatic CHNS analyzer. The reaction progress was controlled by TLC on aluminum foilꢀ
backed silica gel plates, visualization under UV light and in iodine vapor, eluent CH2Cl2. Known
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oꢀQM precursors,22b,28 and enaminones 2a,29 9a–e30 were prepared according to the literature
procedures.
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1ꢀ[(Dimethylamino)methyl]ꢀ6ꢀtritylnaphthalenꢀ2ꢀol (1m). Dimethylamine (3 mL of a 33%
aqueous solution, 0.02 mol) and formaldehyde (1.5 mL of a 37% aqueous solution, 0.02 mol)
were added to a solution of 6ꢀtritylnaphthalenꢀ2ꢀol (6.95 g, 0.018 mol) in isopropanol (50 mL) at
40 ºC. The reaction mixture was stored at room temperature for 1 day. The precipitate formed
was filtered off, washed with iceꢀcold isopropanol. Yield: 78%, 6.22 g. Colorless solid, mp 216–
218 °C. IR (KBr) υmax: 2982, 2949, 2826, 2779, 1603, 1489, 1474, 1460, 1441, 1373, 1275,
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1
1256, 1240, 1177, 995, 806, 758, 745, 700 cm–1. H NMR (400 MHz, CDCl3) δ: 2.42 (s, 6H),
4.07 (s, 2H), 7.05 (d, J = 8.9 Hz, 1H), 7.17–7.27 (m, 20H), 7.53 (d, J = 8.7 Hz, 1H), 7.63–7.65
(m, 2H). 13C NMR (100 MHz, CDCl3,) δ: 44.8 (2CH3), 57.8 (CH2), 64.8 (C), 111.4 (C), 119.1
(CH), 120.1 (CH), 126.0 (3CH), 127.6 (6CH), 127.8 (C), 129.4 (CH), 129.8 (CH), 130.8 (C),
131.2 (CH), 131.3 (6CH), 140.9 (C), 146.8 (3C), 157.1 (C). Anal. Calcd (%) for C32H29NO: C,
86.65; H, 6.59; N, 3.16. Found (%): C, 86.54; H, 6.49; N, 3.27.
3,6ꢀDiꢀtertꢀbutylꢀ1ꢀ[(dimethylamino)methyl]naphthalenꢀ2ꢀol (1n). Title compound was
prepared similarly to compound 1m from 3,6ꢀdiꢀtertꢀbutylnaphthalenꢀ2ꢀol (4.6 g, 0.018 mol) in
isopropanol (50 mL) at room temperature. Yield: 80%, 4.51 g. Colorless solid, mp 187–189 °C.
IR (KBr) υmax: 2951, 2901, 2864, 1605, 1572, 1516, 1460, 1425, 1358, 1252, 1234, 1209, 1173,
1090, 997, 905, 839, 808 cm–1. 1H NMR (400 MHz, CDCl3) δ: 1.40 (s, 9H), 1.52 (s, 9H), 2.42 (s,
6H), 4.10 (s, 2H), 7.48 (dd, J = 8.9, J = 2.0 Hz, 1H), 7.66 (s, 1H), 7.69 (d, J = 2.0 Hz, 1H), 7.76
(d, J = 8.9 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ: 29.8 (3CH3), 31.4 (3CH3), 34.5 (C), 35.3
(C), 44.3 (2CH3), 57.4 (CH2), 112.1 (C), 120.3 (CH), 124.0 (CH), 124.5 (CH), 125.5 (CH), 127.9
(C), 129.5 (C), 139.4 (C), 144.9 (C), 156.6 (C). Anal. Calcd (%) for C21H31NO: C, 80.46; H,
9.97; N, 4.47. Found (%): C, 80.32; H, 10.05; N, 4.34.
5ꢀ[(Dimethylamino)methyl]ꢀ6ꢀhydroxyꢀ2ꢀnaphthonitrile (1j). Dimethylamine (3 ml of a
33% aqueous solution, 20 mmol) and formaldehyde (1.5 ml of a 37% aqueous solution, 20
mmol) were added to a solution of 6ꢀhydroxyꢀ2ꢀnaphthonitrile (3.04 g, 18 mmol) in isopropyl
alcohol (10 ml) at 40 ºC. The reaction mixture was stored at room temperature for 1 day. The
precipitate formed was filtered off, washed with iceꢀcold isopropanol. Yield 2.03 g (50%), brown
solid, mp 137–139 °C. IR (KBr): 2955, 2924, 2853, 2220, 1614, 1589, 1578, 1466, 1400, 1381,
1
1369, 1303, 1277, 1242, 1157, 967, 813, 804. H NMR (CDCl3, 400 MHz): δ = 2.43 (s, 6 H,
NMe2), 4.14 (s, 2 H), 7.16 (d, J = 8.7 Hz, 1 H), 7.56 (d, J = 8.5 Hz, 1 H), 7.75–7.77 (m, 2 H),
8.13 (s, 1 H). Anal. Calcd for C14H14N2O: C, 74.36; H, 6.22; N, 12.33. Found: C, 74.31; H, 6.24;
N, 12.38.
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General Experimental Procedure for the Synthesis of 1H-Benzo[f]chromenes 3a–o,
8a–p and 4H-Chromenes 6a–d, 10a–o. A solution of Mannich base 1a–o or quaternary
ammonium salt 7a–d (1.45 mmol) and corresponding enaminone 2a, 9a–e (1.45 mmol) in AcOH
(5 mL) was heated under reflux as much as indicated in tables 2–4. The reaction mixture was
cooled to room temperature and formed precipitate was collected. The crude product was
purified by recrystallization. In cases there was no precipitation (compounds 3h and 3i), reaction
mixture was concentrated under reduced pressure and residue was purified by column
chromatography (silica gel, CCl4).
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1ꢀ(1HꢀBenzo[f]chromenꢀ2ꢀyl)ꢀ2,2,2ꢀtrifluoroethanꢀ1ꢀone (3a). Yield: 76%, 305 mg.
Colorless solid, mp 112–114 °C (ethanol). IR (KBr) υmax: 1682, 1643, 1616, 1593, 1512, 1462,
1
1358, 1265, 1238, 1211, 1184, 1146, 922, 814 cm–1. H NMR (400 MHz, DMSOꢀd6) δ: 3.73 (s,
2H), 7.29 (d, J = 8.9 Hz, 1H), 7.52 (t, J = 7.3 Hz, 1H), 7.62 (t, J = 7.3 Hz, 1H), 7.83 (d, J = 8.2
Hz, 1H), 7.87 (d, J = 8.9 Hz, 1H), 7.93 (d, J = 8.9 Hz, 1H), 8.22 (s, 1H). 13C NMR (100 MHz,
1
DMSOꢀd6) δ: 19.4 (CH2), 110.6 (С), 112.5 (С), 116.8 (q, JС–F = 288.9 Hz, CF3), 117.3 (СH),
123.4 (СH), 126.1 (СH), 128.0 (СH), 128.9 (СH), 129.5 (СH), 131.4 (С), 131.5 (С), 146.1 (С),
2
157.4 (q, 4JС–F = 5.7 Hz, СH), 179.1 (q, JС–F = 34.3 Hz, C). Anal. Calcd (%) for C15H9F3O2: C,
64.75; H, 3.26. Found (%): C, 64.88; H, 3.29.
2,2,2ꢀTrifluoroꢀ1ꢀ(1ꢀphenylꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl)ethanꢀ1ꢀone (3b). Yield: 61%, 315
mg. Colorless solid, mp 139–141°C (ethanol). IR (KBr) υmax: 3033, 2885, 1681, 1640, 1590,
1242, 1211, 1145, 824 cm–1. 1H NMR (400 MHz, DMSOꢀd6) δ: 5.64 (s, 1 H), 7.06 (tt, J = 7.3, J
= 1.4 Hz, 1H), 7.19 (t, J = 7.6 Hz, 2H), 7.30–7.33 (m, 2H), 7.40–7.51 (m, 3H), 7.90 (d, J = 8.2
Hz, 1H), 7.94 (d, J = 8.9 Hz, 1H), 8.03 (d, J = 8.2 Hz, 1H), 8.42 (s, 1H). 13C NMR (100 MHz,
1
DMSOꢀd6) δ: 35.3 (CH), 115.5 (С), 116.62 (С), 116.63 (q, JС–F = 289.9 Hz, CF3), 117.4 (СH),
123.9 (СH), 126.0 (СH), 127.4 (СH), 127.9 (СH), 128.8 (2СH), 129.0 (2СH), 129.2 (СH), 130.2
(СH), 130.7 (С), 132.1 (С), 144.2 (С), 146.7 (С), 157.1 (q, 4JС–F = 5.7 Hz, СH), 178.2 (q, 2JС–F
=
34.3 Hz, C). Anal. Calcd (%) for C21H13F3O2: C, 71.19; H, 3.70. Found (%): C, 71.03; H, 3.62.
2,2,2ꢀTrifluoroꢀ1ꢀ[1ꢀ(thiophenꢀ2ꢀyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]ethanꢀ1ꢀone (3c). Yield:
83%, 435 mg. Lightꢀyellow solid, mp 141–142 °C (ethanol). IR (KBr) υmax: 3062, 2916, 1685,
1
1643, 1589, 1238, 1211, 1138, 810 cm–1. H NMR (400 MHz, DMSOꢀd6) δ: 6.01 (s, 1H), 6.80
(dd, J = 5.0, J = 3.7 Hz, 1H), 6.90 (d, J = 3.0 Hz, 1H), 7.24 (dd, J = 5.0, J = 0.9 Hz, 1H), 7.46–
7.57 (m, 3H), 7.94 (d, J = 8.5 Hz, 1H), 7.97 (d, J = 9.2 Hz, 1H), 8.08 (d, J = 8.5 Hz, 1H), 8.45 (s,
1H). 13C NMR (100 MHz, DMSOꢀd6) δ: 30.0 (CH), 115.1 (C), 116.3 (C), 116.7 (q, 1JС–F = 289.9
Hz, CF3), 117.4 (CH), 123.7 (CH), 125.9 (CH), 126.2 (CH), 126.4 (CH), 127.2 (CH), 128.1
4
(CH), 129.2 (CH), 130.5 (CH), 130.7 (C), 132.1 (C), 146.7 (C), 147.6 (C), 157.5 (q, JС–F = 5.7
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Hz, СH), 178.2 (q, JС–F = 34.3 Hz, C). Anal. Calcd (%) for C19H11F3O2S: C, 63.33; H, 3.08; S,
8.90. Found (%): C, 63.45; H, 2.94; S, 8.78.
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2,2,2ꢀTrifluoroꢀ1ꢀ[1ꢀ(3ꢀnitrophenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]ethanꢀ1ꢀone (3d). Yield:
50%, 290 mg. Lightꢀyellow solid, mp 150–152 °C (ethanol). IR (KBr) υmax: 3086, 2924, 1693,
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1639, 1589, 1531, 1354, 1242, 1207, 1138, 821 cm–1. H NMR (400 MHz, CDCl3) δ: 5.82 (s,
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1H), 7.39–7.51 (m, 4H), 7.77 (d, J = 7.8 Hz, 1H), 7.82–7.88 (m, 3H), 7.99 (ddd, J = 8.2, J = 2.3,
J = 0.9 Hz, 1H), 8.08 (s, 1H), 8.13 (t, J = 1.8 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ: 35.5
1
(CH), 114.6 (C), 114.8 (C), 116.4 (q, JС–F = 288.9 Hz, CF3), 117.0 (CH), 122.4 (CH), 123.0
(CH), 123.5 (CH), 125.9 (CH), 127.9 (CH), 129.0 (CH), 129.5 (CH), 130.48 (C), 130.55 (CH),
4
132.2 (C), 134.8 (CH), 145.3 (C), 147.0 (C), 148.6 (C), 156.0 (q, JС–F = 5.7 Hz, СH), 178.7 (q,
2JС–F = 35.3 Hz, C). Anal. Calcd (%) for C21H12F3NO4: C, 63.16; H, 3.03; N, 3.51. Found (%): C,
63.27; H, 2.96; N, 3.42.
1ꢀ[1ꢀ(4ꢀChlorophenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]ꢀ2,2,2ꢀtrifluoroethanꢀ1ꢀone (3e). Yield:
61%, 345 mg. Colorless solid, mp 144–146 °C (ethanol). IR (KBr) υmax: 3025, 2883, 1683, 1640,
1592, 1241, 1211, 1145, 819 cm–1. 1H NMR (400 MHz, CDCl3) δ: 5.68 (s, 1 H), 7.18 (d, J = 8.5
Hz, 2H), 7.28 (d, J = 8.5 Hz, 2H), 7.37 (d, J = 8.9 Hz, 1H), 7.41–7.49 (m, 2H), 7.81 (d, J = 8.8
Hz, 2H), 7.87 (d, J = 8.5 Hz, 1H), 8.03 (s, 1H). 13C NMR (100 MHz, CDCl3) δ: 35.1 (СH), 115.3
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(C), 115.7 (C), 116.5 (q, JС–F = 288.9 Hz, CF3), 116.8 (CH), 123.4 (CH), 125.7 (CH), 127.6
(CH), 128.8 (3CH), 129.9 (CH), 130.0 (2CH), 130.8 (C), 132.1 (C), 132.9 (C), 141.9 (C), 146.9
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2
(C), 155.5 (q, JС–F = 5.7 Hz, СH), 178.7 (q, JС–F = 35.3 Hz, C). Anal. Calcd (%) for
C21H12ClF3O2: C, 64.88; H, 3.11. Found (%): C, 64.95; H, 3.06.
2,2,2ꢀTrifluoroꢀ1ꢀ[1ꢀ(4ꢀfluorophenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]ethanꢀ1ꢀone (3f). Yield:
65%, 350 mg. Colorless solid, mp 208–210 °C (isopropanol). IR (KBr) υmax: 3059, 1685, 1641,
1
1589, 1504, 1244, 1213, 1157, 1132, 927, 813, 742, 725 cm–1. H NMR (400 MHz, CDCl3) δ:
5.69 (s, 1 H), 6.89 (t, J = 8.7 Hz, 2H), 7.28–7.33 (m, 2H), 7.37 (d, J = 9.2 Hz, 1H), 7.40–7.49 (m,
2H), 7.81 (d, J = 8.5 Hz, 2H), 7.89 (d, J = 8.2 Hz, 1H), 8.01 (s, 1 H). 13C NMR (100 MHz,
2
1
CDCl3) δ: 34.9 (СH), 115.5 (d, JС–F = 21.0 Hz, 2CH), 115.6 (C), 116.0 (C), 116.5 (q, JС–F
=
289.8 Hz, CF3), 116.8 (CH), 123.4 (CH), 125.7 (CH), 127.6 (CH), 128.8 (CH), 129.8 (CH),
3
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130.2 (d, JС–F = 7.6 Hz, 2CH), 130.8 (C), 132.1 (C), 139.2 (C), 146.9 (C), 155.4 (q, JС–F = 5.7
1
2
Hz, СH), 161.7 (d, JС–F = 244.1 Hz, C–F), 178.7 (q, JС–F = 35.3 Hz, C). Anal. Calcd (%) for
C21H12F4O2: C, 67.75; H, 3.25. Found (%): C, 67.80; H, 3.20.
1ꢀ(1ꢀ[3ꢀChlorophenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]ꢀ2,2,2ꢀtrifluoroethanꢀ1ꢀone (3g). Yield:
54%, 305 mg. Colorless solid, mp 143–145 °C (isopropanol). IR (KBr) υmax: 3067, 2924, 1686,
1
1639, 1589, 1466, 1242, 1207, 1165, 1142, 934, 848, 814 cm–1. H NMR (400 MHz, CDCl3) δ:
5.68 (s, 1 H), 7.09 (d, J = 8.0 Hz, 1H), 7.16 (td, J = 7.3, J = 2.0 Hz, 1H), 7.25–7.29 (m, 2H), 7.38
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(dd, J = 8.9, J = 2.0 Hz, 1H), 7.42–7.51 (m, 2H), 7.82 (d, J = 8.7 Hz, 2H), 7.88 (d, J = 8.0 Hz,
1H), 8.03 (s, 1H). 13C NMR (100 MHz, CDCl3) δ: 35.3 (СH), 115.1 (C), 115.5 (C), 116.5 (q, 1JС–
F = 289.9 Hz, CF3), 116.9 (CH), 123.3 (CH), 125.7 (CH), 127.0 (CH), 127.5 (CH), 127.7 (CH),
128.7 (CH), 128.8 (CH), 129.8 (CH), 130.0 (CH), 130.8 (C), 132.1 (C), 134.6 (C), 145.2 (C),
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2
147.0 (C), 155.6 (q, JС–F = 5.7 Hz, СH), 178.6 (q, JС–F = 35.3 Hz, C). Anal. Calcd (%) for
C21H12ClF3O2: C, 64.88; H, 3.11. Found (%): C, 64.74; H, 3.03.
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2,2,2ꢀTrifluoroꢀ1ꢀ[1ꢀ(3,4,5ꢀtrimethoxyphenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]ethanꢀ1ꢀone (3h).
Yield: 56%, 360 mg. Colorless solid, mp 157–159 °C (isopropanol). IR (KBr) υmax: 3064, 2997,
2938, 2837, 1692, 1644, 1616, 1591, 1504, 1464, 1240, 1201, 1169, 1126, 999, 929, 819 cm–1.
1H NMR (400 MHz, CDCl3) δ: 3.74 (s, 9H), 5.65 (s, 1H), 6.51 (s, 2H), 7.37 (d, J = 8.9 Hz, 1H),
7.42–7.51 (m, 2H), 7.79–7.85 (m, 2H), 7.96 (d, J = 8.2 Hz, 1H), 8.01 (s, 1H). 13C NMR (100
MHz, CDCl3) δ: 35.6 (CH), 56.2 (2CH3), 60.8 (CH3), 105.8 (2CH), 115.6 (C), 116.1 (C), 116.5
(q, 1JС–F = 289.4 Hz, CF3), 116.7 (CH), 123.6 (CH), 125.7 (CH), 127.5 (CH), 128.7 (CH), 129.7
(CH), 131.1 (C), 132.1 (C), 137.0 (C), 139.0 (C), 147.0 (C), 153.2 (2C), 155.4 (q, 4JС–F = 5.7 Hz,
2
СH), 178.8 (q, JС–F = 35.3 Hz, C). Anal. Calcd (%) for C24H19F3O5: C, 64.86; H, 4.31. Found
(%): C, 64.99; H, 4.22.
1ꢀ(8ꢀBromoꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl)ꢀ2,2,2ꢀtrifluoroethanꢀ1ꢀone (3i). Yield: 71%, 367
mg. Colorless solid, mp 173–174 °C (ethanol). IR (KBr) υmax: 3117, 3082, 2905, 1690, 1647,
1612, 1585, 1501, 1354, 1238, 1203, 1172, 1130, 1076, 968, 922, 864, 806, 729 cm–1. 1H NMR
(400 MHz, CDCl3) δ: 3.77 (s, 2H), 7.21 (d, J = 8.9 Hz, 1H), 7.63 (d, J = 8.7 Hz, 1H), 7.65–7.70
(m, 2H), 7.92 (s, 1H), 7.97 (s, 1H). 13C NMR (100 MHz, CDCl3) δ: 19.5 (CH2), 110.3 (С), 112.5
(С), 116.6 (q, 1JС–F = 288.9 Hz, CF3), 118.1 (СH), 119.8 (С), 124.6 (СH), 128.1 (СH), 130.2 (С),
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130.5 (СH), 130.8 (СH), 132.4 (С), 146.3 (С), 156.2 (q, JС–F = 5.7 Hz, CH), 179.5 (q, JС–F
=
35.6 Hz, C). Anal. Calcd (%) for C15H8BrF3O2: C, 50.45; H, 2.26. Found (%): C, 50.30; H, 2.16.
2ꢀ(2,2,2ꢀTrifluoroacetyl)ꢀ1Hꢀbenzo[f]chromeneꢀ8ꢀcarbonitrile (3j). Yield: 45%, 198 mg.
Colorless solid, mp 210–213 °C (isopropanol). IR (KBr) υmax: 3113, 2224, 1684, 1641, 1595,
1
1585, 1468, 1394, 1240, 1209, 1190, 1132, 891, 814, 735 cm–1. H NMR (400 MHz, CDCl3) δ:
3.87 (s, 2H), 7.34 (d, J = 8.9 Hz, 1H), 7.76 (d, J = 8.7 Hz, 1H), 7.83 (d, J = 8.7 Hz, 1H), 7.95 (s,
1H), 7.96 (d, J = 8.9 Hz, 1H), 8.22 (s, 1H). 13C NMR (100 MHz, CDCl3) δ: 19.6 (CH2), 109.4
1
(С), 110.5 (С), 112.76 (C), 112.82 (С), 116.8 (q, JС–F = 288.9 Hz, CF3), 119.0 (СH), 124.3
(СH), 128.2 (СH), 129.6 (СH), 130.4 (С), 133.4 (С), 134.3 (СH), 148.4 (С), 155.9 (q, 4JС–F = 5.7
2
Hz, CH), 179.4 (q, JС–F = 35.6 Hz, C). Anal. Calcd (%) for C16H8F3NO2: C, 63.37; H, 2.66; N,
4.62. Found (%): C, 63.49; H, 2.60; N, 4.51.
1ꢀ[8ꢀ(tertꢀButyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]ꢀ2,2,2ꢀtrifluoroethanꢀ1ꢀone (3k). Yield: 75%,
365 mg. Colorless solid, mp 120–121 °C (ethanol). IR (KBr) υmax: 3078, 2963, 2874, 1689, 1647,
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1601, 1585, 1470, 1396, 1308, 1269, 1219, 1200, 1169, 1134, 906, 733 cm–1. H NMR (400
MHz, CDCl3) δ: 1.43 (s, 9H), 3.83 (s, 2H), 7.18 (d, J = 8.9 Hz, 1H), 7.70–7.73 (m, 2H), 7.78 (s,
1H), 7.81 (d, J = 8.9 Hz, 1H), 7.95 (s, 1H). 13C NMR (100 MHz, CDCl3) δ: 19.5 (CH2), 31.3
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(3CH3), 34.9 (C), 110.4 (С), 111.9 (С), 116.7 (q, JС–F = 288.9 Hz, CF3), 116.7 (СH), 122.7
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(СH), 123.7 (СH), 126.3 (СH), 128.9 (СH), 129.7 (С), 131.4 (С), 145.8 (С), 148.6 (С), 156.5 (q,
4JС–F = 5.7 Hz, CH), 179.6 (q, 2JС–F = 35.3 Hz, C). Anal. Calcd (%) for C19H17F3O2: C, 68.26; H,
5.13. Found (%): C, 68.31; H, 5.06.
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1ꢀ[8ꢀ(Adamantanꢀ1ꢀyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]ꢀ2,2,2ꢀtrifluoroethanꢀ1ꢀone (3l). Yield:
83%, 500 mg. Colorless solid, mp 150–152 °C (isopropanol). IR (KBr) υmax: 3059, 2904, 2851,
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1686, 1647, 1593, 1219, 1173, 1138, 906, 802 cm–1. H NMR (400 MHz, CDCl3) δ: 1.78–1.85
(m, 6H), 1.98–2.02 (m, 6H), 2.15 (br s, 3H), 3.84 (s, 2H), 7.18 (d, J = 8.9 Hz, 1H), 7.69–7.73 (m,
3H), 7.82 (d, J = 8.7 Hz, 1H), 7.95 (s, 1H). 13C NMR (100 MHz, CDCl3) δ: 19.6 (CH2), 29.0
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(3CH), 36.4 (C), 36.9 (3CH2), 43.2 (3CH2), 110.4 (C), 111.9 (C), 116.7 (CH), 116.8 (q, JС–F
=
290.0 Hz, CF3), 122.7 (CH), 123.7 (CH), 125.8 (CH), 129.1 (CH), 129.9 (C), 131.5 (C), 145.8
(C), 148.9 (C), 156.7 (q, 4JС–F = 5.7 Hz, CH), 179.7 (q, 2JС–F = 35.0 Hz, C). Anal. Calcd (%) for
C25H23F3O2: C, 72.80; H, 5.62. Found (%): C, 72.67; H, 5.57.
2,2,2ꢀTrifluoroꢀ1ꢀ(8ꢀtritylꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl)ethanꢀ1ꢀone (3m). Yield: 67%, 505
mg. Yellow solid, mp 118–121 °C (isopropanol). IR (KBr) υmax: 1688, 1645, 1595, 1585, 1491,
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1470, 1441, 1240, 1190, 1171, 1138, 922, 847, 824, 752, 741, 700 cm–1. H NMR (400 MHz,
CDCl3) δ: 3.81 (s, 2H), 7.16 (d, J = 8.7 Hz, 1H), 7.20–7.31 (m, 15H), 7.39 (dd, J = 8.9, J = 2.0
Hz, 1H), 7.61 (d, J = 9.0 Hz, 1H), 7.68 (d, J = 9.0 Hz, 1H), 7.77 (d, J = 1.8 Hz, 1H), 7.95 (s, 1H).
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13C NMR (100 MHz, CDCl3) δ: 19.5 (CH2), 65.0 (C), 110.4 (C), 112.1 (C), 116.7 (q, JС–F
=
289.9 Hz, CF3), 116.8 (CH), 121.8 (CH), 126.2 (3CH), 127.8 (6CH), 128.9 (CH), 129.4 (CH),
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129.9 (C), 130.9 (C), 131.3 (6CH), 132.4 (CH), 144.5 (C), 146.4 (4C), 156.5 (q, JС–F = 5.7 Hz,
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CH), 179.5 (q, JС–F = 35.0 Hz, C). Anal. Calcd (%) for C34H23F3O2: C, 78.45; H, 4.45. Found
(%): C, 78.33; H, 4.36.
1ꢀ(5,8ꢀDiꢀtertꢀbutylꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl)ꢀ2,2,2ꢀtrifluoroethanꢀ1ꢀone (3n). Yield:
58%, 330 mg. Colorless solid, mp 144–146 °C (ethanol). IR (KBr) υmax: 2957, 2912, 2872, 1708,
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1659, 1584, 1572, 1558, 1258, 1200, 1175, 1148, 1138, 916, 735 cm–1. H NMR (400 MHz,
CDCl3) δ: 1.42 (s, 9H), 1.50 (s, 9H), 3.87 (s, 2H), 7.66 (d, J = 9.0 Hz, 1H), 7.69 (s, 1H), 7.76 (s,
1H), 7.78 (d, J = 9.1 Hz, 1H), 8.04 (s, 1H). 13C NMR (100 MHz, CDCl3) δ: 19.7 (CH2), 30.3
(3CH3), 31.3 (3CH3), 34.9 (C), 35.3 (C), 110.2 (С), 112.4 (С), 116.7 (q, 1JС–F = 288.9 Hz, CF3),
122.3 (СH), 123.7 (СH), 125.5 (СH), 125.6 (СH), 128.4 (С), 130.9 (С), 137.7 (С), 145.6 (С),
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148.6 (С), 155.5 (q, JС–F = 5.7 Hz, CH), 179.5 (q, JС–F = 35.3 Hz, C). Anal. Calcd (%) for
C23H25F3O2: C, 70.75; H, 6.45. Found (%): C, 70.70; H, 6.48.
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2ꢀ(2,2,2ꢀTrifluoroacetyl)ꢀ7,9,10,11ꢀtetrahydropyrano[3,2ꢀe]pyrido[3,4ꢀb]indolꢀ8(1H)ꢀone
(3o). Yield: 45%, 220 mg. Colorless solid, mp 295–297 °C (isopropanol). IR (KBr) υmax: 3418,
3179, 3028, 2966, 2866, 1682, 1655, 1632, 1605, 1500, 1427, 1342, 1203, 1169, 1142, 910, 779
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cm–1. H NMR (400 MHz, DMSOꢀd6) δ: 3.09 (t, J = 6.8 Hz, 2H), 3.47 (td, J = 6.8, J = 2.5 Hz,
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2H), 3.82 (s, 2H), 6.95 (d, J = 8.9 Hz, 1H), 7.22 (d, J = 8.9 Hz, 1H), 7.62 (s, 1H), 8.12 (s, 1H),
11.8 (s, 1H). 13C NMR (100 MHz, DMSOꢀd6) δ: 20.0 (CH2), 22.3 (CH2), 41.5 (CH2), 109.3 (C),
111.5 (C), 112.8 (CH), 114.6 (CH), 116.8 (q, 1JС–F = 288.9 Hz, CF3), 119.0 (C), 123.3 (C), 129.3
(C), 135.0 (C), 142.2 (C), 158.1 (q, 4JС–F = 5.7 Hz, CH), 161.9 (C=O), 178.9 (q, 2JС–F = 34.3 Hz,
C). Anal. Calcd (%) for C16H11F3N2O3: C, 57.15; H, 3.30; N, 8.33. Found (%): C, 57.23; H, 3.40;
N, 8.22.
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1ꢀ(6,7ꢀDimethylꢀ4Hꢀchromenꢀ3ꢀyl)ꢀ2,2,2ꢀtrifluoroethanꢀ1ꢀone (8a). Yield: 75%, 280 mg.
Colorless solid, mp 119–121 °C (ethanol). IR (KBr) υmax: 2924, 1689, 1635, 1577, 1508, 1354,
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1219, 1184, 1138, 894 cm–1. H NMR (400 MHz, CDCl3) δ: 2.20 (s, 3H), 2.21 (s, 3H), 3.50 (s,
2H), 6.79 (s, 1H), 6.90 (s, 1H), 7.81 (s, 1H). 13C NMR (100 MHz, CDCl3) δ: 19.2 (CH3), 19.6
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(CH3), 21.2 (CH2), 110.3 (C), 115.9 (C), 116.6 (q, JС–F = 288.9 Hz, CF3), 117.6 (CH), 130.4
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(CH), 134.3 (C), 136.9 (C), 146.9 (C), 157.1 (q, JС–F = 5.7 Hz, CH), 179.4 (q, JС–F = 35.1 Hz,
C). Anal. Calcd (%) for C13H11F3O2: C, 60.94; H, 4.33. Found (%): C, 60.82; H, 4.30.
2,2,2ꢀTrifluoroꢀ1ꢀ(6ꢀmethoxyꢀ4Hꢀchromenꢀ3ꢀyl)ethanꢀ1ꢀone (8b). Yield: 54%, 205 mg.
Colorless solid, mp 134–136 °C (ethanol). IR (KBr) υmax: 2918, 1689, 1630, 1582, 1510, 1219,
1182, 1140, 799 cm–1. 1H NMR (400 MHz, CDCl3) δ: 3.56 (s, 2H), 3.78 (s, 3H), 6.64 (d, J = 2.3
Hz, 1H), 6.73 (dd, J = 8.9, J = 2.3 Hz, 1H), 6.95 (d, J = 8.9 Hz, 1H), 7.81 (s, 1H). 13C NMR (100
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MHz, CDCl3) δ: 22.0 (CH2), 55.7 (CH3), 109.4 (C), 113.8 (CH), 114.0 (CH), 116.6 (q, JС–F
=
4
288.9 Hz, CF3), 117.9 (CH), 120.0 (C), 143.0 (C), 157.0 (q, JС–F = 5.7 Hz, CH), 157.2 (C),
179.2 (q, 2JС–F = 35.3 Hz, C). Anal. Calcd (%) for C12H9F3O3: C, 55.82; H, 3.51. Found (%): C,
55.94; H, 3.41.
1ꢀ(6ꢀtertꢀButylꢀ4Hꢀchromenꢀ3ꢀyl)ꢀ2,2,2ꢀtrifluoroethanone (8c). Yield: 53%, 220 mg.
Colorless solid, mp 112–114 °C (methanol). IR (KBr) υmax: 3118, 3032, 2957, 2906, 2868, 1687,
1633, 1587, 1498, 1274, 1240, 1197, 1186, 1163, 1132, 943, 879, 734 cm–1. 1H NMR (400 MHz,
CDCl3) δ: 1.30 (s, 9H), 3.58 (s, 2H), 6.94 (d, J = 8.5 Hz, 1H), 7.15 (d, J = 2.3 Hz, 1H), 7.22 (dd,
13
J = 8.7, J = 2.3 Hz, 1H), 7.82 (s, 1H). C NMR (100 MHz, CDCl3) δ: 21.9 (CH2), 31.4 (3CH3),
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34.5 (C), 110.3 (C), 116.4 (CH), 116.6 (q, JС–F = 288.9 Hz, CF3), 118.3 (C), 125.3 (CH), 126.5
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(CH), 146.9 (C), 149.1 (C), 157.0 (q, JС–F = 5.7 Hz, CH), 179.3 (q, JС–F = 35.3 Hz, C). Anal.
Calcd (%) for C15H15F3O2: C, 63.38; H, 5.32. Found (%): C, 63.41; H, 5.38.
1ꢀ[(6ꢀAdamantanꢀ1ꢀyl)ꢀ4Hꢀchromenꢀ3ꢀyl]ꢀ2,2,2ꢀtrifluoroethanꢀ1ꢀone (8d). Yield: 59%,
310 mg. Colorless solid, mp 142–144 °C (methanol). IR (KBr) υmax: 3109, 3066, 3043, 2935,
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2881, 2846, 1689, 1631, 1585, 1496, 1261, 1120, 1130, 937, 887, 806, 752 cm–1. H NMR (400
MHz, CDCl3) δ: 1.71–1.80 (m, 6H), 1.86–1.88 (m, 6H), 2.09 (br s, 3H), 3.58 (s, 2H), 6.96 (d, J =
8.5 Hz, 1H), 7.12 (d, J = 2.3 Hz, 1H), 7.20 (dd, J = 8.5, J = 2.3 Hz, 1H), 7.82 (s, 1H). 13C NMR
(100 MHz, CDCl3) δ: 21.9 (CH2), 29.0 (3CH), 36.1 (C), 36.8 (3CH2), 43.3 (3CH2), 110.3 (C),
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116.5 (CH), 116.7 (q, JС–F = 289.8 Hz, CF3), 118.4 (C), 125.0 (CH), 126.2 (CH), 146.9 (C),
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149.4 (C), 157.1 (q, JС–F = 5.7 Hz, CH), 179.4 (q, JС–F = 34.8 Hz, C). Anal. Calcd (%) for
C21H21F3O2: C, 69.60; H, 5.84. Found (%): C, 69.50; H, 5.78.
(1HꢀBenzo[f]chromenꢀ2ꢀyl)(phenyl)methanone (10a). Yield: 75%, 310 mg. Colorless solid,
mp 158–160 °C (ethanol). IR (KBr) υmax: 1655, 1628, 1593, 1512, 1466, 1439, 1389, 1323, 1281,
1223, 1180, 972, 910, 849, 814, 716 cm–1. 1H NMR (400 MHz, CDCl3) δ: 4.01 (s, 2H), 7.17 (d, J
= 8.7 Hz, 1H), 7.45–7.57 (m, 5H), 7.61 (t, J = 7.6 Hz, 1H), 7.68 (d, J = 7.1 Hz, 2H), 7.72 (d, J =
8.9 Hz, 1H), 7.84 (d, J = 8.0 Hz, 1H), 7.95 (d, J = 8.4 Hz, 1 H). 13C NMR (100 MHz, CDCl3) δ:
20.6 (СH2), 112.9 (C), 115.2 (C), 117.1 (CH), 123.1 (CH), 125.2 (CH), 127.2 (CH), 128.4 (CH),
128.5 (2CH), 128.6 (CH), 128.9 (2CH), 131.1 (C), 131.5 (CH), 132.1 (C), 138.8 (C), 146.8 (C),
155.2 (СH), 195.7 (C). Anal. Calcd (%) for C20H14O2: C, 83.90; H, 4.93. Found (%): C, 84.07;
H, 4.85.
Phenyl(1ꢀphenylꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl)methanone (10b). Yield: 80%, 420 mg.
Colorless solid, mp 209–211 °C (ethanol). IR (KBr) υmax: 1639, 1593, 1454, 1381, 1319, 1231,
1192, 991, 849, 833, 814, 729, 698 cm–1. H NMR (400 MHz, CDCl3) δ: 6.02 (s, 1H), 7.08 (t, J
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= 7.3 Hz, 1H), 7.20 (t, J = 7.5 Hz, 2H), 7.32 (d, J = 8.9 Hz, 1H), 7.37–7.44 (m, 7H), 7.49 (t, J =
7.4 Hz, 1H), 7.54 (d, J = 7.3 Hz, 2H), 7.76–7.80 (m, 2H), 7.99 (d, J = 8.2 Hz, 1H). 13C NMR
(100 MHz, CDCl3) δ: 36.5 (CH), 116.5 (C), 117.1 (CH), 120.6 (C), 123.8 (CH), 125.0 (CH),
126.6 (CH), 127.1 (CH), 128.4 (2CH), 128.5 (3CH), 128.6 (2CH), 128.9 (2CH), 129.2 (CH),
131.6 (C), 131.70 (CH), 131.74 (C), 138.8 (C), 144.8 (C), 148.7 (C), 152.6 (CH), 194.9 (C).
Anal. Calcd (%) for C26H18O2: C, 86.16; H, 5.01. Found (%): C, 86.02; H, 4.89
[1ꢀ(3ꢀNitrophenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl](phenyl)methanone (10c). Yield: 64%, 380
mg. Lightꢀyellow solid, mp 175–177 °C (ethanol). IR (KBr) υmax: 1636, 1593, 1531, 1350, 1319,
1277, 1227, 1180, 1080, 988, 922, 849, 810, 729, 694 cm–1. 1H NMR (400 MHz, CDCl3) δ: 6.12
(s, 1H), 7.36–7.54 (m, 9H), 7.57 (s, 1H), 7.82–7.89 (m, 4H), 7.96 (d, J = 8.0 Hz, 1H), 8.18 (s,
1H). 13C NMR (100 MHz, CDCl3) δ: 36.4 (CH), 115.0 (C), 117.3 (CH), 119.3 (C), 122.0 (CH),
123.2 (CH), 123.4 (CH), 125.4 (CH), 127.5 (CH), 128.6 (2CH), 128.8 (2CH), 128.9 (CH), 129.4
(CH), 130.0 (CH), 131.1 (C), 131.88 (C), 131.93 (CH), 134.9 (CH), 138.3 (C), 146.8 (C), 147.8
(C), 148.7 (C ), 153.8 (CH), 194.4 (C). Anal. Calcd (%) for C26H17NO4: C, 76.65; H, 4.21; N,
3.44. Found (%): C, 76.81; H, 4.15; N, 3.32.
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[1ꢀ(4ꢀMethoxyphenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl](phenyl)methanone (10d). Yield: 85%,
485 mg. Colorless solid, mp 212–214 °C (ethanol). IR (KBr) υmax: 1639, 1593, 1508, 1462, 1381,
1319, 1312, 1257, 1227, 1177, 1037, 833, 810, 698 cm–1. 1H NMR (400 MHz, CDCl3) δ: 3.69 (s,
3H), 5.97 (s, 1H), 6.73 (d, J = 8.7 Hz, 2H), 7.28–7.32 (m, 3H), 7.36–7.51 (m, 6H), 7.54–7.56 (m,
2H), 7.75–7.80 (m, 2H), 7.99 (d, J = 8.5 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ: 35.7 (CH),
55.2 (СH3), 113.9 (2CH), 116.7 (C), 117.1 (CH), 120.7 (C), 123.9 (CH), 125.0 (CH), 127.1
(CH), 128.4 (2CH), 128.5 (CH), 128.9 (2CH), 129.1 (CH), 129.5 (2CH), 131.6 (C), 131.7 (CH),
131.8 (C), 137.3 (C), 138.8 (C), 147.7 (C), 152.4 (CH), 158.1 (C), 195.0 (C). Anal. Calcd (%)
for C27H20O3: C, 82.63; H, 5.14. Found (%): C, 82.52; H, 5.19.
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(1HꢀBenzo[f]chromenꢀ2ꢀyl)(2ꢀhydroxyphenyl)methanone (10e). Yield: 68%, 297 mg.
Colorless solid, mp 163–165 °C (ethanol). IR (KBr) υmax: 3300–2600, 1628, 1601, 1570, 1466,
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1443, 1400, 1354, 1308, 1265, 1231, 1142, 991, 822, 760, 687 cm–1. H NMR (400 MHz,
CDCl3) δ: 4.19 (s, 2H), 7.27 (d, J = 9.2 Hz, 1H), 7.32 (t, J = 7.8 Hz, 1H), 7.39 (t, J = 7.6 Hz,
1H), 7.43 (d, J = 8.3 Hz, 1H), 7.53 (ddd, J = 8.3, J = 6.9, J = 1.2 Hz, 1H), 7.64–7.69 (m, 2Н),
7.78 (d, J = 8.0 Hz, 1H), 7.97 (d, J = 8.5 Hz, 1H), 8.23 (dd, J = 8.0, J = 1.4 Hz, 1H), 8.38 (s, 1H),
10.15 (br s, 1H). 13C NMR (100 MHz, CDCl3) δ: 22.2 (CH2), 116.5 (C), 118.1 (CH), 121.0 (CH),
121.6 (CH), 122.9 (CH), 123.0 (C), 123.5 (C), 125.6 (CH), 126.1 (CH), 126.6 (CH), 129.1 (CH),
129.3 (CH), 129.6 (C), 133.1 (C), 134.4 (CH), 153.5 (C), 154.2 (CH), 156.6 (C), 180.2 (C).
Anal. Calcd (%) for C20H14O3: C, 79.46; H, 4.67. Found (%): C, 79.30; H, 4.56.
(1ꢀPhenylꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl)(pꢀtolyl)methanone (10f). Yield: 75%, 410 mg.
Colorless solid, mp 205–206 °C (ethanol). IR (KBr) υmax: 1639, 1601, 1508, 1454, 1416, 1377,
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1304, 1254, 1227, 1177, 1026, 988, 837, 810, 760, 698 cm–1. H NMR (400 MHz, CDCl3) δ:
2.38 (s, 3H), 6.02 (s, 1H), 7.08 (tt, J = 7.3, J = 1.2 Hz, 1H), 7.17–7.21 (m, 4H), 7.31 (d, J = 8.9
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Hz, 1H), 7.36–7.48 (m, 7H), 7.76–7.80 (m, 2H), 7.98 (d, J = 8.5 Hz, 1H). C NMR (100 MHz,
CDCl3) δ: 21.6 (CH3), 36.6 (CH), 116.4 (C), 117.1 (CH), 120.5 (C), 123.9 (CH), 125.0 (CH),
126.6 (CH), 127.1 (CH), 128.48 (2CH), 128.50 (CH), 128.6 (2CH), 129.1 (4CH), 129.2 (CH),
131.6 (C), 131.7 (C), 136.0 (C), 142.4 (C), 144.8 (C), 147.8 (C), 152.0 (CH), 194.7 (C). Anal.
Calcd (%) for C27H20O2: C, 86.14; H, 5.36. Found (%): C, 86.25; H, 5.32.
[1ꢀ(3ꢀNitrophenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl](pꢀtolyl)methanone (10g). Yield: 60%, 365
mg. Lightꢀyellow solid, mp 188–190 °C (ethanol). IR (KBr) υmax: 1636, 1593, 1528, 1462, 1350,
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1315, 1227, 1180, 991, 922, 853, 826, 810, 756 cm–1. H NMR (400 MHz, CDCl3) δ: 2.39 (s,
3H), 6.11 (s, 1H), 7.21 (d, J = 7.3 Hz, 2H),7.35–7.46 (m, 6H), 7.56 (s, 1H), 7.81–7.88 (m, 4H),
7.96 (d, J = 8.0 Hz, 1H), 8.15 (s, 1H). 13C NMR (100 MHz, CDCl3) δ: 21.6 (CH3), 36.5 (CH),
115.0 (C), 117.3 (CH), 119.2 (C), 121.9 (CH), 123.3 (CH), 123.4 (CH), 125.3 (CH), 127.5 (CH),
128.8 (CH), 129.0 (2CH), 129.2 (2CH), 129.4 (CH), 130.0 (CH), 131.1 (C), 131.8 (C), 134.9
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(CH), 135.6 (C), 142.7 (C), 146.9 (C), 147.8 (C), 148.6 (C), 153.2 (CH), 194.2 (C). Anal. Calcd
(%) for C27H19NO4: C, 76.95; H, 4.54; N, 3.32. Found (%): C, 76.82; H, 4.62; N, 3.25.
[1ꢀ(4ꢀMethoxyphenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl](pꢀtolyl)methanone (10h). Yield: 70%,
410 mg. Colorless solid, mp 210–212 °C (ethanol). IR (KBr) υmax: 1639, 1609, 1589, 1508, 1462,
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1439, 1400, 1373, 1315, 1227, 1184, 1107, 1026, 988, 922, 829, 810, 745 cm–1. H NMR (400
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MHz, CDCl3) δ: 2.38 (s, 3H), 3.68 (s, 3H), 5.97 (s, 1H), 6.72 (d, J = 7.8 Hz, 2H), 7.19 (d, J = 7.4
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Hz, 2Н), 7.26–7.51 (m, 8H), 7.74–7.80 (m, 2H), 7.98 (d, J = 8.2 Hz, 1H). C NMR (100 MHz,
CDCl3) δ: 21.6 (CH3), 35.8 (CH), 55.2 (CH3), 113.9 (2CH), 116.7 (C), 117.1 (CH), 120.6 (C),
123.9 (CH), 125.0 (CH), 127.1 (CH), 128.5 (CH), 129.07 (3CH), 129.10 (2CH), 129.4 (2CH),
131.6 (C), 131.7 (C), 136.1 (C), 137.3 (C), 142.4 (C), 147.8 (C), 151.8 (CH), 158.1 (С), 194.8
(C). Anal. Calcd (%) for C28H22O3: C, 82.74; H, 5.46. Found (%): C, 82.70; H, 5.36.
(1HꢀBenzo[f]chromenꢀ2ꢀyl)(4ꢀchlorophenyl)methanone (10i). Yield: 74%, 340 mg.
Colorless solid, mp 210–212 °C (ethanol) (lit. mp 198–199 °C).13 IR (KBr) υmax: 1632, 1593,
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1520, 1466, 1319, 1281, 1231, 1180, 1088, 972, 833, 810, 741 cm–1. H NMR (400 MHz,
CDCl3) δ: 4.01 (s, 2H), 7.18 (d, J = 8.9 Hz, 1H), 7.45–7.52 (m, 4H), 7.60–7.66 (m, 3H), 7.74 (d,
J = 9.0 Hz, 1H), 7.85 (d, J = 8.0 Hz, 1H), 7.95 (d, J = 8.2 Hz, 1H). 13C NMR (100 MHz, CDCl3)
δ: 20.5 (CH2), 112.8 (C), 115.2 (C), 117.1 (CH), 123.1 (CH), 125.3 (CH), 127.2 (CH), 128.4
(CH), 128.6 (CH), 128.8 (2CH), 130.3 (2CH), 131.1 (C), 132.1 (C), 137.0 (C), 137.9 (C), 146.8
(C), 155.1 (СH), 194.3 (C). Anal. Calcd (%) for C20H13ClO2: C, 74.89; H, 4.08. Found (%): C,
74.99; H, 4.01.
(4ꢀChlorophenyl)(1ꢀphenylꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl)methanone (10j). Yield: 73%, 420
mg. Colorless solid, mp 163–165 °C (ethanol). IR (KBr) υmax: 3028, 2916, 1643, 1593, 1311,
1222, 1188, 837 cm–1. 1H NMR (400 MHz, CDCl3) δ: 6.00 (s, 1H), 7.09 (t, J = 7.3 Hz, 1H), 7.21
(t, J = 7.8 Hz, 2H), 7.32 (d, J = 8.9 Hz, 1H), 7.36–7.45 (m, 7H), 7.49 (d, J = 8.5 Hz, 2H), 7.78 (d,
J = 8.9 Hz, 1H), 7.79 (d, J = 7.1 Hz, 1H), 7.98 (d, J = 8.5 Hz, 1H). 13C NMR (100 MHz, CDCl3)
δ: 36.6 (CH), 116.3 (C), 117.1 (CH), 120.5 (C), 123.8 (CH), 125.1 (CH), 126.7 (CH), 127.2
(CH), 128.5 (2CH), 128.56 (CH), 128.65 (2CH), 128.8 (2CH), 129.3 (CH), 130.3 (2CH), 131.5
(C), 131.8 (C), 137.0 (C), 138.1 (C), 144.7 (C), 147.7 (C), 152.5 (CH), 193.6 (C). Anal. Calcd
(%) for C26H17ClO2: C, 78.69; H, 4.32. Found (%): C, 78.79; H, 4.24.
(4ꢀChlorophenyl)[1ꢀ(3ꢀnitrophenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]methanone (10k). Yield:
65%, 415 mg. Lightꢀyellow solid, mp 237–239 °C (ethanol). IR (KBr) υmax: 1632, 1589, 1524,
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1396, 1346, 1315, 1227, 1192, 1088, 991, 822, 806, 760, 741, 683 cm–1. H NMR (400 MHz,
CDCl3) δ: 6.08 (s, 1H), 7.36–7.49 (m, 8H), 7.54 (s, 1H), 7.81–7.87 (m, 4H), 7.96 (ddd, J = 8.2, J
= 2.0, J = 0.9 Hz, 1H), 8.15 (t, J = 2.0 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ: 36.4 (CH), 114.9
(C), 117.2 (CH), 119.2 (C), 122.0 (CH), 123.2 (CH), 123.3 (CH), 125.4 (CH), 127.6 (CH), 128.9
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(3CH), 129.4 (CH), 130.1 (CH), 130.2 (2CH), 131.0 (C), 131.9 (C), 134.8 (CH), 136.6 (C),
138.3 (C), 146.7 (C), 147.7 (C), 148.6 (C), 153.7 (CH), 193.1 (C). Anal. Calcd (%) for
C26H16ClNO4: C, 70.67; H, 3.65; N, 3.17. Found (%): C, 70.52; H, 3.71; N, 3.06.
(4ꢀChlorophenyl)[1ꢀ(4ꢀmethoxyphenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]methanone (10l). Yield:
69%, 425 mg. Colorless solid, mp 156–158 °C (ethanol). IR (KBr) υmax: 1639, 1589, 1508, 1462,
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CDCl3) δ: 3.68 (s, 3H), 5.94 (s, 1H), 6.73 (d, J = 8.7 Hz, 2H), 7.27 (d, J = 8.7 Hz, 2H), 7.31 (d, J
= 8.9 Hz, 1H), 7.35–7.46 (m, 5H), 7.49 (d, J = 8.2 Hz, 2H), 7.75–7.80 (m, 2H), 7.97 (d, J = 8.5
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Hz, 1H). C NMR (100 MHz, CDCl3) δ: 35.7 (CH), 55.2 (CH3), 114.0 (2CH), 116.6 (C), 117.1
(CH), 120.6 (C), 123.8 (CH), 125.1 (CH), 127.2 (CH), 128.6 (CH), 128.7 (2CH), 129.2 (CH),
129.4 (2CH), 130.3 (2CH), 131.5 (C), 131.8 (C), 137.1 (2C), 138.0 (C), 147.6 (C), 152.3 (CH),
158.2 (С), 193.8 (C). Anal. Calcd (%) for C27H19ClO3: C, 75.97; H, 4.49. Found (%): C, 76.12;
H, 4.40.
(4ꢀMethoxyphenyl)(1ꢀphenylꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl)methanone (10m). Yield: 68%, 385
mg. Colorless solid, mp 175–177 °C (ethanol). IR (KBr) υmax: 1639, 1601, 1512, 1458, 1319,
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1304, 1258, 1227, 1177, 1026, 837 cm–1. H NMR (400 MHz, CDCl3) δ: 3.82 (s, 3H), 6.03 (s,
1H), 6.88 (d, J = 8.7 Hz, 2H), 7.07 (t, J = 7.3 Hz, 1H), 7.19 (t, J = 7.6 Hz, 2H), 7.31–7.44 (m,
6H), 7.57 (d, J = 8.7 Hz, 2H), 7.76–7.80 (m, 2H), 7.97 (d, J = 8.2 Hz, 1H). 13C NMR (100 MHz,
CDCl3) δ: 36.9 (CH), 55.5 (CH3), 113.7 (2CH), 116.4 (C), 117.1 (CH), 120.4 (C), 123.9 (CH),
125.0 (CH), 126.6 (CH), 127.1 (CH), 128.4 (2CH), 128.5 (CH), 128.6 (2CH), 129.2 (CH), 131.2
(2CH), 131.3 (C), 131.6 (C), 131.7 (C), 144.9 (C), 147.9 (C), 151.0 (CH), 162.7 (C), 193.8 (C).
Anal. Calcd (%) for C27H20O3: C, 82.63; H, 5.14. Found (%): C, 82.55; H, 5.12.
(4ꢀMethoxyphenyl)[1ꢀ(4ꢀmethoxyphenyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl]methanone
(10n).
Yield: 68%, 415 mg. Colorless solid, mp 173–175 °C (ethanol). IR (KBr) υmax: 1639, 1601,
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1508, 1462, 1319, 1265, 1227, 1180, 1107, 1026, 988, 918, 841, 825, 810, 752 cm–1. H NMR
(400 MHz, CDCl3) δ: 3.68 (s, 3H), 3.83 (s, 3H), 5.97 (s, 1H), 6.71 (d, J = 7.3 Hz, 2H), 6.88 (d, J
= 7.4 Hz, 2H), 7.25–7.31 (m, 3H), 7.35–7.45 (m, 3H), 7.58 (d, J = 7.4 Hz, 2H), 7.74–7.79 (m,
2H), 7.96 (d, J = 8.5 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ: 36.0 (CH), 55.2 (CH3), 55.5
(CH3), 113.7 (2CH), 113.9 (2CH), 116.6 (C), 117.1 (CH), 120.5 (C), 123.9 (CH), 124.9 (CH),
127.0 (CH), 128.5 (CH), 129.0 (CH), 129.4 (2CH), 131.2 (2CH), 131.3 (C), 131.6 (C), 131.7
(C), 137.3 (C), 147.8 (C), 150.8 (CH), 158.1 (С), 162.7 (C), 193.9 (C). Anal. Calcd (%) for
C28H22O4: C, 79.60; H, 5.25. Found (%): C, 79.72; H, 5.18.
[1ꢀ(1ꢀBenzylꢀ1Hꢀimidazolꢀ5ꢀyl)ꢀ1Hꢀbenzo[f]chromenꢀ2ꢀyl](phenyl)methanone
(10o).
Yield: 85%, 545 mg. Colorless solid, mp 228–229 °C (isopropanol). IR (KBr) υmax: 3117, 3086,
3059, 3024, 2966, 2908, 2854, 1647, 1627, 1593, 1492, 1323, 1300, 1276, 1222, 1180, 991, 925,
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848, 817, 729, 678 cm–1. 1H NMR (400 MHz, CDCl3) δ: 5.32 (d, J = 15.8 Hz, 1H), 5.71 (d, J =
15.8 Hz, 1H), 5.96 (s, 1H), 6.68 (s, 1H), 6.99 (d, J = 8.5 Hz, 1H), 7.05 (t, J = 7.8 Hz, 1H), 7.25
(d, J = 8.7 Hz, 1H), 7.30–7.34 (m, 3H), 7.40–7.47 (m, 6H), 7.53–7.56 (m, 4H), 7.72 (d, J = 8.9
Hz, 1H), 7.73 (d, J = 7.6 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ: 26.4 (CH), 49.3 (CH2), 114.3
(C), 117.0 (CH), 119.0 (C), 122.9 (CH), 125.2 (CH), 127.4 (CH), 127.9 (2CH), 128.5 (CH),
128.6 (CH), 128.66 (2CH), 128.73 (CH), 129.0 (2CH), 129.3 (2CH), 129.8 (CH), 130.9 (C),
131.7 (C), 132.2 (CH), 135.6 (C), 136.1 (C), 137.6 (СH), 138.2 (C), 147.9 (C), 154.6 (CH),
195.1 (C). Anal. Calcd (%) for C30H22N2O2: C, 81.43; H, 5.01; N, 6.33. Found (%): C, 81.48; H,
4.89; N, 6.20.
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General Experimental Procedure for the Synthesis of 3-Benzoyl-4H-chromenes 13a–
d. To a solution of 2ꢀhydroxybenzyl alcohol (2 mmol) 12a–d in Ac2O (4 mL) enaminone 9a (2
mmol) was added. The mixture was heated for 2h under reflux, cooled to room temperature. The
precipitate was filtered off, washed with H2O. The crude product was purified by
recrystallization from ethanol.
Phenyl(4ꢀphenylꢀ4Hꢀchromenꢀ3ꢀyl)methanone (13a). Yield: 66%, 410 mg. Colorless solid,
mp 196–197 °C. IR (KBr) υmax: 3097, 3024, 3003, 1633, 1600, 1575, 1487, 1450, 1386, 1321,
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1292, 1224, 1178, 1155, 1101, 958, 920, 785, 752, 727, 696 cm–1. H NMR (400 MHz, CDCl3)
δ: 5.34 (s, 1H), 7.02–7.07 (m, 2H), 7.10–7.20 (m, 3H), 7.25 (t, J = 7.7 Hz, 2H), 7.31–7.34 (m,
2H), 7.40 (t, J = 7.9 Hz, 2H), 7.46 (s, 1H), 7.49 (tt, J = 8.7, J = 1.3 Hz, 1H), 7.56–7.59 (m, 2H).
13C NMR (100 MHz, CDCl3) δ: 39.3 (CH), 116.7 (CH), 119.5 (C), 124.4 (C), 125.3 (CH), 126.8
(CH), 128.0 (CH), 128.3 (2CH), 128.4 (2CH), 128.7 (2CH), 128.9 (2CH), 130.5 (CH), 131.7
(CH), 138.7 (C), 145.7 (C), 149.2 (C), 153.5 (CH), 194.7 (C). Anal. Calcd (%) for C22H16O2: C,
84.59; H, 5.16. Found (%): C, 84.47; H, 5.10.
[8ꢀ(Adamantanꢀ1ꢀyl)ꢀ6ꢀmethylꢀ4Hꢀchromenꢀ3ꢀyl](phenyl)methanone (13b). Yield: 41%,
315 mg. Colorless solid, mp 140–142 °C. IR (KBr) υmax: 2911, 2897, 2878, 2849, 1628, 1593,
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1449, 1391, 1323, 1292, 1209, 1179, 1103, 866, 849, 725, 702 cm–1. H NMR (400 MHz,
CDCl3) δ: 1.74 (br s, 6H), 2.05 (br s, 9H), 2.29 (s, 3H), 3.69 (s, 2H), 6.85 (s, 1H), 6.91 (s, 1 H),
7.42 (s, 1H), 7.44–7.55 (m, 3H), 7.61–7.65 (m, 2H). 13C NMR (100 MHz, CDCl3) δ: 21.2 (CH3),
23.0 (CH2), 29.1 (3CH), 36.9 (C), 37.0 (3CH2), 41.0 (3CH2), 115.1 (C), 120.2 (C), 126.3 (CH),
128.1 (CH), 128.5 (2CH), 128.7 (2CH), 131.3 (CH), 134.0 (C), 137.8 (C), 139.0 (C), 146.7 (C),
155.1 (CH), 195.5 (C). Anal. Calcd (%) for C27H28O2: C, 84.34; H, 7.34. Found (%): C, 84.21;
H, 7.37.
(8ꢀMethoxyꢀ4Hꢀchromenꢀ3ꢀyl)(phenyl)methanone (13c). Yield: 50%, 265 mg. Colorless
solid, mp 191–193 °C. IR (KBr) υmax: 1643, 1612, 1578, 1477, 1439, 1396, 1315, 1273, 1215,
1084, 856, 767, 706 cm–1. 1H NMR (400 MHz, CDCl3) δ: 3.73 (s, 2H), 3.88 (s, 3H), 6.78 (d, J =
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2H). C NMR (100 MHz, CDCl3) δ: 22.7 (CH2), 56.1 (CH3), 110.3 (CH), 115.0 (C), 121.2 (C),
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(C), 155.2 (CH), 195.3 (C). Anal. Calcd (%) for C17H14O3: C, 76.68; H, 5.30. Found (%): C,
76.79; H, 5.28.
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[6ꢀ(Adamantanꢀ1ꢀyl)ꢀ8ꢀbromoꢀ4Hꢀchromenꢀ3ꢀyl](phenyl)methanone (13d). Yield: 25%,
225 mg. Colorless solid, mp 143–145 °C. IR (KBr) υmax: 2901, 2847, 1628, 1568, 1468, 1447,
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1325, 1288, 1219, 1169, 889, 702 cm–1. H NMR (400 MHz, CDCl3) δ: 1.71–1.80 (m, 6H),
1.85–1.87 (m, 6H), 2.09–2.11 (m, 3H), 3.75 (s, 2H), 7.09 (d, J = 2.3 Hz, 1H), 7.37 (d, J = 2.3 Hz,
1H), 7.40–7.46 (m, 3H), 7.50–7.55 (m, 1H), 7.61–7.65 (m, 2H). 13C NMR (100 MHz, CDCl3) δ:
23.5 (CH2), 28.9 (3CH), 36.1 (C), 36.7 (3CH2), 43.2 (3CH2), 110.6 (C), 115.5 (C), 121.3 (C),
125.6 (CH), 128.5 (2CH), 128.6 (CH), 128.8 (2CH), 131.7 (CH), 138.4 (C), 144.5 (C), 149.4
(C), 155.2 (CH), 195.1 (C). Anal. Calcd (%) for C26H25BrO2: C, 69.49; H, 5.61. Found (%): C,
69.56; H, 5.56.
Synthesis of Chromene 13a in mixture of o-Xylene and acetic anhydride. To a solution
of 2ꢀ(hydroxy(phenyl)methyl)phenol (2 mmol) 12a and in enaminone 9a (2 mmol) in oꢀxylene
(4 ml) acetic anhydride (2 mmol) was added. The mixture was heated for 3h under reflux, cooled
to room temperature. The precipitate was filtered off, washed with H2O. The crude product was
purified by recrystallization from ethanol. Yield of 13a – 67%, 417 mg.
Synthesis of 1H-Benzo[f]chromene 3a in o-Xylene.
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mixture of 1ꢀ
[(dimethylamino)methyl]naphthalenꢀ2ꢀol 1a (500 mg, 2.5 mmol) and enaminone 2a (520 mg, 2.5
mmol) in oꢀxylene (5 mL) was heated at reflux temperature for 5 h. The solvent was removed by
evaporation under reduced pressure and the residue was separated by column chromatography
(silica gel, CHCl3). 2,3ꢀDihydroꢀ1Hꢀbenzo[f]chromenꢀ3ꢀol 5 (15%, 100 mg), 1,1,1ꢀtrifluoroꢀ4ꢀ
morpholinobutꢀ3ꢀenꢀ2ꢀone 2a (25%, 130 mg), 4ꢀ(dimethylamino)ꢀ1,1,1ꢀtrifluorobutꢀ3ꢀenꢀ2ꢀone
2b (36%, 150 mg), 1Hꢀbenzo[f]chromene 3a (17%, 120 mg) and Mannich base 4 (49%, 300 mg)
were isolated. Products 5,31 2b32 and 433 were identical in melting point and spectral
characteristics to literature data.
Reaction of Mannich Bases 1b and 1e with Enaminone 2a in Ac2O. When Ac2O was
used instead of AcOH as a solvent, only diacetates 6a and 6b were isolated under the conditions
previously indicated. After refluxing for 3 h, excess of Ac2O was evaporated under reduced
pressure and diacetates 6a and 6b were purified by column chromatography (silica gel, CCl4).
1ꢀ[Acetoxy(phenyl)methyl]naphthalenꢀ2ꢀyl acetate (6a). Yield: 76%, 370 mg. Colorless
solid, mp 103–105 °C. Product was identical in spectral characteristics to a sample prepared
previously.34
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1ꢀ[Acetoxy(4ꢀchlorophenyl)methyl]naphthalenꢀ2ꢀyl acetate (6b). Yield: 80%, 430 mg.
Yellow solid, mp 149–150 °C (ethanol). IR (KBr) υmax: 1747, 1489, 1362, 1223, 1204, 1169,
1088, 1065, 1011, 964, 810, 764 cm–1. 1H NMR (400 MHz, CDCl3) δ: 2.14 (s, 3H), 2.35 (s, 3H),
7.15 (d, J = 8.5 Hz, 2H), 7.24–7.27 (m, 3H), 7.37–7.45 (m, 2H), 7.76 (s, 1H), 7.84 (d, J = 8.0 Hz,
1H), 7.89 (d, J = 9.0 Hz, 1H), 8.00 (d, J = 8.5 Hz, 1H). 13C NMR (100 MHz, CDCl3) δ: 21.0
(CH3), 21.1 (CH3), 69.0 (CH), 122.0 (CH), 124.9 (C), 125.6 (CH), 125.7 (CH), 126.9 (CH),
127.1 (2CH), 128.7 (2CH), 128.8 (CH), 130.9 (CH), 131.7 (C), 132.6 (C), 133.3 (C), 138.2 (C),
147.7 (C), 169.8 (C=O), 170.2 (C). Anal. Calcd (%) for C21H17ClO4: C, 68.39; H, 4.65. Found
(%): C, 68.28; H, 4.53.
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5ꢀ[(2ꢀHydroxynaphthalenꢀ1ꢀyl)methyl]ꢀ2ꢀoxoꢀ6ꢀ(trifluoromethyl)ꢀ1,2ꢀdihydropyridineꢀ3ꢀ
carbonitrile (14a). A solution of chromene 3a (200 mg, 0.72 mmol), malononitrile (50 mg, 0.76
mmol) and DABCO (85 mg, 0.76 mmol) in acetonitrile (5 mL) was heated at reflux temperature
for 7 h. The reaction mixture was stored at –20 ºC for 12 h and formed precipitate collected. The
crude product was purified by recrystallization from ethanol. Yield: 69%, 0.17 g. Yellow solid,
mp 217–218 ºС. IR (KBr) υmax: 3476, 3383, 3175, 2218, 1701, 1601, 1582, 1470, 1369, 1346,
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1292, 1234, 1188, 1142, 1015, 810 cm–1. H NMR (400 MHz, DMSOꢀd6) δ: 4.24 (s, 2H), 7.26
(d, J = 8.9 Hz, 1H), 7.51–7.55 (m, 1H), 7.63–7.69 (m, 2H), 7.86–7.95 (m, 4H), 8.05 (s, 1H). 13C
NMR (100 MHz, DMSOꢀd6) δ: 23.9 (CH2), 109.9 (C), 111.3 (C), 112.4 (C), 116.8 (C), 117.0
(CH), 120.1 (q, 1JC–F = 274.6 Hz, CF3), 123.0 (CH), 126.2 (CH), 128.3 (CH), 129.1 (CH), 129.8
2
(CH), 131.1 (C), 131.4 (C), 142.4 (q, JC–F = 34.3 Hz, CCF3), 143.8 (CH), 145.7 (C), 162.0 (C).
Anal. Calcd (%) for C18H11F3N2O2: C, 62.79; H, 3.22; N, 8.14. Found (%): C, 62.69; H, 3.18; N,
8.09.
5ꢀ[(2ꢀHydroxynaphthalenꢀ1ꢀyl)methyl]ꢀ2ꢀthioxoꢀ6ꢀ(trifluoromethyl)ꢀ1,2ꢀdihydropyridineꢀ
3ꢀcarbonitrile (14b). A solution of chromene 3a (300 mg, 1.1 mmol), cyanothioacetamide (120
mg, 1.2 mmol) and DABCO (130 mg, 1.2 mmol) in acetonitrile (5 mL) was heated at reflux
temperature for 3 h. The reaction mixture was cooled to room temperature and formed
precipitate was collected. The thiolate salt of DBU was suspended in isopropanol (4 mL),
neutralized with conc. HCl until pH 4 and then poured into water (6 mL). The precipitate that
formed was filtered off, washed with water and recrystallized from benzene. Yield: 63%, 250
mg. Yellow solid, mp 218–219 °C. IR (KBr) υmax: 3500–3000, 2234, 1628, 1582, 1514, 1439,
1422, 1379, 1358, 1329, 1308, 1296, 1271, 1209, 1182, 1105, 1092, 1065, 991, 860, 816, 748.
1H NMR (400 MHz, DMSOꢀd6) δ: 4.45 (s, 2H), 7.26–7.30 (m, 2H), 7.37 (t, J = 8.2 Hz, 1H), 7.40
(s, 1H), 7.50 (d, J = 8.5 Hz, 1H), 7.80–7.84 (m, 2H), 10.05 (s, 1H). The NH proton signal does
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not appear, probably due to a fast exchange with deuterium. C NMR (100 MHz, DMSOꢀd6) δ:
25.4 (CH2), 112.0 (C), 113.7 (C), 114.5 (C), 118.9 (CH), 121.8 (q, 1JC–F = 275.5 Hz, CF3), 122.3
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(CH), 123.3 (CH), 127.4 (CH), 129.1 (C), 129.2 (CH), 130.0 (CH), 133.6 (C), 135.6 (C), 144.1
(CH), 147.4 (q, 2JC–F = 33.4 Hz, CF3), 154.2 (C), 155.8 (C). Anal. Calcd (%) for C18H11F3N2OS:
C, 60.00; H, 3.08; N, 7.77; S, 8.90. Found (%): C, 60.13; H, 2.96; N, 7.68; S, 8.79.
1ꢀ[(3ꢀ(Trifluoromethyl)ꢀ1Hꢀpyrazolꢀ4ꢀyl)methyl]naphthalenꢀ2ꢀol (15a). A solution of
chromene 3a (300 mg, 1.1 mmol) in hydrazine hydrate (5 mL) was heated at reflux temperature
for 1 h. The solvent was removed by evaporation under reduced pressure and the residue was
recrystallized from methanol. Yield: 75%, 235 mg. Colorless solid, mp 221–223 °C. IR (KBr)
υmax: 3343, 3300–3100, 1630, 1584, 1506, 1462, 1437, 1379, 1354, 1341, 1312, 1292, 1275,
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1244, 1182, 1146, 1117, 1078, 1045, 993, 957, 812, 754 cm–1. H NMR (400 MHz, DMSOꢀd6)
δ: 4.17 (s, 2Н), 6.86 (s, 1Н), 7.20–7.25 (m, 2Н), 7.36 (t, J = 7.6 Hz, 1H), 7.64 (d, J = 8.5 Hz,
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1Н), 7.69 (d, J = 9.0 Hz, 1Н), 7.76 (d, J = 8.0 Hz, 1Н), 9.73 (s, 1Н), 13.16 (br s, 1Н). C NMR
(100 MHz, DMSOꢀd6) δ: 19.0 (СН2), 116.9 (С), 118.7 (СН), 119.1 (С), 122.9 (СН), 123.0 (СН),
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123.3 (q, JC–F = 271.7 Hz, CF3), 126.9 (СН), 128.6 (СН), 128.8 (С), 128.9 (СН), 129.9 (СН),
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133.5 (С), 138.4 (q, JC–F = 35.3 Hz, CCF3 ), 153.1 (C). Anal. Calcd (%) for C15H11F3N2O: C,
61.65; H, 3.79; N, 9.59. Found (%): C, 61.54; H, 3.77; N, 9.47.
1ꢀ[(3ꢀPhenylꢀ1Hꢀpyrazolꢀ4ꢀyl)methyl]naphthalenꢀ2ꢀol (15b). Title compound was prepared
similarly to compound 15a from chromene 10a. Yield: 76%, 250 mg. Colorless solid, mp 208–
209 °C (ethanol). IR (KBr) υmax: 3389, 3200–2800, 1678, 1624, 1576, 1504, 1472, 1437, 1412,
1354, 1302, 1275, 1248, 1103, 978, 947, 812, 739, 694, 665 cm–1. 1H NMR (400 MHz, CD3CN)
δ: 2.23 (br. s, single averaged peak with residual water, NH, OH), 4.30 (s, 2 H), 6.75 (s, 1H),
7.16 (d, J = 9.0 Hz, 1H), 7.22–7.31 (m, 2H), 7.38–7.42 (m, 1H), 7.47–7.52 (m, 2H), 7.61 (d, J =
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8.5 Hz, 1H), 7.67 (d, J = 9.0 Hz, 1H), 7.75–7.79 (m, 3H). C NMR (100 MHz, CD3CN) δ: 20.3
(CH2), 117.8 (C), 118.0 (CH), 118.6 (C), 122.8 (CH), 123.2 (CH), 126.3 (CH), 127.69 (CH),
127.73 (2CH), 128.0 (CH), 128.4 (CH), 128.7 (2CH), 129.1 (C), 132.6 (CH), 133.2 (C), 133.4
(C), 145.4 (C), 151.8 (C). Anal. Calcd (%) for C20H16N2O: C, 79.98; H, 5.37; N, 9.33. Found
(%): C, 80.08; H, 5.27; N, 9.24.
1ꢀ[(5ꢀPhenylisoxazolꢀ4ꢀyl)methyl]naphthalenꢀ2ꢀol (16). An 1 M solution of hydroxylamine
in methanol (3 mL) was added to a suspension of chromene 10a (250 mg, 0.87 mmol) in
methanol (5 mL) and the mixture was heated at reflux temperature for 1 h. The solvent was
removed by evaporation under reduced pressure and the residue was recrystallized from ethanol.
Yield: 80%, 210 mg. Colorless solid, mp 171–173 °C. IR (KBr) υmax: 3500–3000, 1628, 1605,
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1578, 1514, 1441, 1389, 1354, 1277, 1254, 1159, 1109, 1067, 995, 897, 812, 770, 746, 691. H
NMR (400 MHz, DMSOꢀd6) δ: 4.18 (s, 2H), 7.20–7.25 (m, 2H), 7.30–7.35 (m, 1H), 7.53–7.59
(m, 3H), 7.63 (d, J = 8.5 Hz, 1H), 7.70 (d, J = 8.7 Hz, 1H), 7.77 (d, J = 8.0 Hz, 1H), 7.82–7.85
(m, 2H), 7.89 (s, 1H), 9.81 (s, 1H). 13C NMR (100 MHz, DMSOꢀd6) δ: 19.0 (CH2), 116.7 (C),
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118.6 (C), 118.7 (CH), 122.9 (CH), 123.1 (CH), 127.0 (CH), 128.77 (2CH, C), 128.81 (CH),
128.9 (CH), 129.6 (2CH, C), 130.3 (CH), 133.3 (C), 153.0 (C), 158.1 (CH), 161.3 (C). Anal.
Calcd (%) for C20H15NO2: C, 79.72; H, 5.02; N, 4.65. Found (%): C, 79.87; H, 4.97; N, 4.57.
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ACKNOWLEDGMENT
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This work was supported by the Ministry of Education and Science of the Russian Federation
(the Agreement number 02.a03.21.0008) and by the Russian Foundation for Basic Research
(grant 16ꢀ33ꢀ00773 mol_a).
Supporting Information
Copies of 1H, 13C NMR and DEPT spectra for all new synthesized compounds.
This material is available free of charge via the Internet at http://pubs.acs.org.
ORCID
Dmitry V. Osipov: 0000ꢀ0001ꢀ9217ꢀ0792
Notes
The authors declare no competing financial interest.
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