On the formation and 1H NMR-spectroscopic characterization of N,N-diaryl-substituted formamide chlorides

Article abstract of DOI:10.1515/znb-2012-0401

The reaction of N,N-diaryl-substituted formamides with oxalyl chloride gives rise, instead to the formation of the expected salt-like formamide chlorides, to the formation of corresponding non-ionic N-dichloromethyl- substituted diarylamines.

Full text of DOI:10.1515/znb-2012-0401

On the Formation and 1H NMR-spectroscopic Characterization
of N,N-Diaryl-substituted Formamide Chlorides
Jens Scho¨newerka and Horst Hartmann
Department Chemie, Technische Universita¨t Dresden, 01062 Dresden, Germany
a Present address: SEMA GmbH, Industriestraße 12, 06869 Coswig, Germany
Reprint requests to Prof. Dr. Horst Hartmann. Fax: +49-3514-6339485. E-mail: Hartmann@iapp.de
Z. Naturforsch. 2012, 67b, 277 – 284; received January 16, 2012
Dedicated to Prof. Klaus Mu¨llen to the occasion of his 65th birthday
The reaction of N,N-diaryl-substituted formamides with oxalyl chloride gives rise, instead to the
formation of the expected salt-like formamide chlorides, to the formation of corresponding non-ionic
N-dichloromethyl-substituted diarylamines.
Key words: Vilsmeier Reaction, N,N-Diaryl-Formamides,
N-Dichloromethyl-substituted Diarylamines, 1H NMR Spectroscopy
Introduction
the aldehydes 6 could finally be obtained by hydrolysis
(Scheme 1).
In contrast to the formamides 1a and 1b, N,N-
diaryl-substituted formamides have not been ap-
plied for the VR hitherto. The parent N,N-diphenyl-
formamide 1c was used, however, for the synthesis of
certain products containing the N,N-diphenylamino-
methine moiety. Thus, N,N,Nꢀ-triphenyl-formamid-
ine [5] N,N-diphenyl-cyanamide [6], N,N-diphenyl-
amino-trifluoromethane [7], and 1,2-bis-(N,N-diphen-
ylamino)-1,2-dichloroethylene[8], have been prepared
by starting with this formamide derivative. Although
for all these reactions the formation of the correspond-
ing N,N-diphenyl-substituted formamide chloride 3c
can be assumed, an unambiguous proof for this com-
pound has not been given as yet, however. Such proof
was envisaged by us now by means of NMR measure-
ments.
As known, the Vilsmeier-Haak reaction (VR) is a
versatile method for preparing aromatic or heteroaro-
matic aldehydes in an enormous variety [1]. Originally
a mixture of N-methylformanilide (1b) and POCl3 (2a,
Y = PCl2) was used for this method [2]. Later on, in-
stead of these reagents the cheaper DMF (1a) as well as
other inorganic and organic acid chlorides, especially
phosgene (2b, Y = CCl) or oxalyl chloride (2c, Y =
CCOCl), were used [3].
In the course of the VR both reactants, the N,N-di-
substitued formamides 1 and the acid chlorides 2, are
transformed into reactive chloroformamidinium chlo-
rides 3 which are able to react with suitable nucle-
ophilic substrates, like an aromatic or heteroaromatic
compound of the general formula 4, to yield, in a first
step, the corresponding iminium salts 5 [4] from which
Scheme 1. Formation of
iminium salts 5 and alde-
hydes 6.
c
ꢀ 2012 Verlag der Zeitschrift fu¨r Naturforschung, Tu¨bingen · http://znaturforsch.com
Brought to you by | University of Georgia Libraries
Authenticated
Download Date | 5/27/15 4:45 AM

278
J. Scho¨newerk – H. Hartmann · N,N-Diaryl-substituted Formamide Chlorides
X
1 (X = O−)
3 (X = Cl)
7 (X = S−)
8 (X = Se−)
9 (X = −NC6H5) Table 1. Chemical shifts of
the R2N=CHX protons in
7.93a [9, 10]
7.92b [11]
8.02c [25]
7.95d [25]
10.10a [9, 10]
11.08b [11]
9.21d [15]
9.21d [16]
10.56d [17]
10.62d [18]
10.32d [19]
7.40d [20]
compounds 1, 3, 7 – 9.
a
8.48 [21]
8.53c [25]
8.48d [25]
9.51a [9]
9.64e [12]
11.17d [18]
11.22d [22]
8.10d [13]
b
9.36 / 9.46b [14]
8.55d [23]
8.64d [24]
7.60d,f
10.0d [16]
8.67d [20]
11.75d [16]
8.18d [25]
a
In CD2Cl2; b in CD3CN; c in
c
d
e
[D6]DMSO; in CDCl3; in
CCl4; f own measurement.
Table 2. 1H NMR chemical
shifts of methine protons
of some formamide deriva-
tives.
R
3
10
1
2
8
9
a
Me2N 10.10a [9]
7.93a [9]
9.21a [15] 10.62a [18]
10.32b [19]
7.40a [20]
b
c
d
e
f
MePhN 9.51a [9]
8.48a [25] 9.64c [12] 11.22 / 11.71a [22] 8.10a [13]
Ph2N
MeO
MeS
Cl
7.60
8.64a [24] 10.0a [16] 11.75a [16]
8.07a [40] 9.66a [26]
8.18a [25]
7.33a [30]
7.08c [31]
7.26d [41]
In CDCl3; b in C6D6;
a
10.12d [26] 11.33a [27]
c
in CCl4; d neat.
9.70a [29] 9.74a [28]
Results and Discussion
are summarized in Table 1 and Table 2 and discussed
below.
As can be seen from Table 1, the transforma-
tion of the formamides 1a and 1b into the cor-
responding formamide chlorides 3a and 3b is ac-
companied by a shift of the proton signal at the
formyl moiety to lower field. This shift is larger
Formamide chlorides 3a and 3b exhibit, similar to
other N,N-dialkyl substituted formamide chlorides [9],
1
in the H NMR spectra characteristic singlets at δ ≈
10 ppm, and a signal in the same region was thus ex-
pected also for the proton at the methine-iminium moi-
ety in 3c. To our surprise, this was not the case, how- for the N,N-dimethyl-substituted compound 3a than
for the N-methyl-N-phenyl-substituted compound 3b
and goes in line with the shifts observed by go-
ing from these formamides to the appropriate thio-
formamides 7a and 7b and selenoformamides 8a
and 8b. The shift of the signals of these com-
pounds is obviously due to the corresponding het-
ever. Independently of the acyl chloride 2 used for the
transformation of N,N-diphenylformamide (1c) into
its formamide chloride 3c, no signals for the methine
proton at about 10 ppm could be detected. Thus, with
POCl3 as example, no reaction was observed, whereas
with (COCl)2 a transformation of the starting mate-
rial 1c into a product occurs. For this product, a new eroatoms S and Se, which polarize the C=X bond more
1H NMR signal at higher field at δ ≈ 7.7 ppm could
strongly than the oxygen due their lower π-π overlap
strength.
be detected.
To check whether this finding is a speciality for
In contrast, by going from N,N-diphenyl-form-
N,N-diphenylformamide (1c), the 1H NMR spectra amide (1c) to the putative formamide chloride
of several other N,N-diaryl-substituted formamides derivate 3c a shift of the signals to higher field is
were measured after the reaction with oxalyl chlo- observed in contrast to the shift observed by going
ride and compared with those of other N,N-diaryl- from 1c to the thio- and selenoformamide deriva-
substituted formamide derivatives, such as N,N-diar- tives 7c and 8c, respectively. A shift to higher field is
yl-substituted thioformamides 7, selenoformamides 8, also found for N,N,Nꢀ-triphenyl-formamidine(9c) rel-
and formamides 9 (Scheme 1). The results obtained ative to N,N-diphenyl-formamide (1c).
Brought to you by | University of Georgia Libraries
Authenticated
Download Date | 5/27/15 4:45 AM

J. Scho¨newerk – H. Hartmann · N,N-Diaryl-substituted Formamide Chlorides
279
Scheme 2.
Scheme 3.
The observed abnormality in the chemical shift of
A similar behavior is found for some other N,N-di-
the proton signal of compound 3c can be explained aryl-substituted formamides, such as compounds 1g –
by assuming that this compound exists contrary to 1q (Scheme 3). By reaction with oxalyl chloride 2b,
compounds 3a and 3b in the non-ionic structure 10c these compounds are transformed into products the
(Scheme 2) in which both chlorine atoms are cova- 1H NMR spectra of which indicate the exclusive ex-
lently bound at the methine C atom. This statement is istence of the non-ionic dichloro compounds 10d –
supported by the values of the proton signals at δ ≈ 10q and not of the corresponding formamide chlorides.
7.33, 7.08 and 7.26 ppm found for compounds 10d, The same result was also found with the methoxy-sub-
10e and 10f, respectively, in which both chlorine atoms stituted N,N-diarylformamides 1h and 1j which con-
are also covalently bound at the methine C atom. In tain a donor-substituent able to stabilize cationic struc-
compounds 10a and 10b the proton signals are found tures at the phenyl groups.
at significantly higher field than the same signals in the
thiono compounds 7a and 7b and in the seleno com-
pounds 8a and 8b (Table 2).
It is worth mentioning that the formamide deriva-
tive 1r derived from carbazole can not be transformed
neither into the corresponding formamide chloride 3r
Brought to you by | University of Georgia Libraries
Authenticated
Download Date | 5/27/15 4:45 AM

280
J. Scho¨newerk – H. Hartmann · N,N-Diaryl-substituted Formamide Chlorides
Scheme 4. Stereoisomers of the
naphthyl-substituted formamide
1d.
Scheme 5. Formation of the salts 13
and 14 and the aldehyde 15.
Table 3. 1H NMR chemical shifts of methine protons of some
formamide derivatives.
moieties at their N atoms, such as the formamides 1g –
1j and 1l, another peculiarity was found. These com-
pounds exhibit two separated singlets for the methine
protons at the CH=O groups. This separation obviously
is caused by the existence of stereoisomers and goes in
line with observations in the 1H NMR spectra of other
unsymmetrically N,N-substituted formamides, e. g. N-
alkyl-substituted N-naphthylformamides [32] and N-
methyl-N-phenyl-thioformamide (8c) [12], each of
which also exist as two stereoisomers. Although for
the naphthyl-substituted formamides 1g – 1j, as exem-
plified for 1g in Scheme 4, four different stereoiso-
mers 1g, 1gꢀ, 1gꢀꢀ, and 1gꢀꢀꢀ are possible, only 1g
and 1gꢀ seem to exist according to the NMR detected
signals.
The separation of the signals of the stereoisomers
vanishes, however, by going from the formyl deriva-
tives 1g – 1j and 1l to the corresponding dichloro com-
pounds 10g – 10j and 10l. The signal separation in the
formamides 1g – 1j and 1l is observed not only for the
signals of the formyl protons at δ ≈ 8.8 ppm but also
for the signals of all other protons in these compounds.
The size of the signal separation depends, however, on
the relative position of these protons with respect to the
formyl groups and is rather large for the naphthalene
protons at C-8 and significantly smaller for the other
naphthalene protons.
Compound
Chem. shift δ
Compound
Chem. shift δ
1g
1h
1i
9.06 / 8.57
8.92 / 8.54
8.78 / 8.75
8.79 / 8.65
8.85
9.09 / 8.58
8.81
8.88
8.65
8.31
8.58
9.68
10g
10h
10i
7.57
7.65
7.71
7.71
7.84
7.66
7.81
7.72
7.54
7.25
7.57
–
1j
10j
1k
1l
10k
10l
1m
1n
1o
1p
1q
1r
1s
10m
10n
10o
10p
10q
10r
10s
9.11 / 9.50
7.81
nor into the dichloro compound 10r, and that the
formamide derivative 1l derived from 1,1-dinaphthyl-
amine needs an excess of oxalyl chloride and a longer
reaction time for a complete transformation into the
product 10l. Obviously, the 1,1-dinaphthylamine moi-
ety in 1k on the one hand strongly screens the re-
active formyl group, and the carbazole moiety is, on
the other hand, a much weaker electron donor than
the other N,N-diarylamines used as formamide build-
ing blocks. The last-mentioned fact is reflected also
1
by the H NMR signal of the formyl proton in com-
pound 1r at δ ≈ 9.69 ppm which is significantly shifted
to lower field in comparison to the signals of the other
formamide derivatives considered (Table 3).
1
The existence of the N,N-diaryl-substituted form-
amide chlorides 3 as isomeric dichloro-compounds 10
By inspecting the H NMR spectra of the N,N-di- stimulated us to investigate the reactivity of these non-
aryl-substituted formamides containing different aryl ionic compounds towards some nucleophilic reagents,
Brought to you by | University of Georgia Libraries
Authenticated
Download Date | 5/27/15 4:45 AM

J. Scho¨newerk – H. Hartmann · N,N-Diaryl-substituted Formamide Chlorides
281
e. g. towards electron-rich aromatics. Therefore, N,N- 8.4 Hz, 1 arom. H), 7.91 – 7.96 (m, 2 arom. H), 8.57, 9.06 (ds,
1H, CH=O). – C17H13NO (247.1): calcd. C 82.57, H 5.30,
N 5.66; found C 82.81, H 5.61, N 5.81.
diphenyl-formamide 1c was allowed to react – after its
transformation into the dichloro compound 10c by re-
action with oxalyl chloride – with diphenylamine (11)
and with N,N-dimethyl-aniline (12). In both cases a re-
action occurs giving rise to the formation of the salts 13
and 14, respectively (Scheme 5). The formamidinium
salt 13 was isolated by addition of tetrafluoroboric acid
to the pristine reaction mixture diluted with methanol,
whereas 14 was not isolated but transformed into 4-
(N,N-dimethylamino)benzaldehyde (15) by pouring
the reaction mixture into an aqueous sodium carbon-
ate solution and extracting the deeply colored reaction
product with dichloromethane followed by purification
by column chromatography.
N-(4-Methoxyphenyl)-N-(1-naphthyl)-formamide (1h)
From N-(4-methoxyphenyl)-1-naphthylamine, prepared
according to ref. [39]; oil. – 1H NMR (CDCl3): δ = 3.76/3.77
(ds, 3H, OCH3), 6.85 (dd, J = 9.1 Hz, 2 arom. H), 7.33 (d, 1
arom. H), 7.47 – 7.56 (m, 3 arom. H), 7.86 – 7.94 (m, 3 aro-
mat. H), 8.00 (s, 1 arom. H), 8.54, 8.92 (ds, 1H, CH=O). –
C18H15NO (277.3): calcd. C 77.96, H 5.45, N 5.05; found
C 77.68, H 5.61, N 4.81.
N-(2-Naphthyl)-N-phenyl-formamide (1i)
From N-phenyl-2-naphthylamine; m. p. 106 ◦C.
–
Although these results demonstrate the aptness of
N,N-diaryl-substituted formamides for VR, the rather
complicated isolation procedure, by which the product
has to be separated from the diarylamine by-product,
suggests that it is of little synthetic value.
1H NMR (CDCl3): δ = 7.20 – 7.29 (m, 2 arom. H), 7.33 –
7.40 (m, 4 arom. H), 7.47 – 7.52 (m, 1 arom. H), 7.53 – 7.58
(m, 1 arom. H), 7.76, 7.85 (dd, J = 2.1 Hz, 1 arom. H),
7.82 – 7.86 (m, 3 arom. H), 8.75, 8.78 (ds, 1H, CH=O). –
C17H13NO (247.1): calcd. C 82.57, H 5.30, N 5.66; found
C 82.97, H 5.64, N 5.75.
Experimental Section
1H NMR spectra were recorded in CDCl3 with a Bruker
DRX 500 P instrument at 500.13 MHz. Mass spectra were
obtained with a Bruker Esquire-LC 00084 instrument at 10 V
with electrospray ionization using methanol containing 0.1 %
ammonium acetate. The melting points were measured with
a Boetius heating-table microscope and are uncorrected.
N-(4-Methoxyphenyl)-N-(2-naphthyl)formamide (1j)
From N-(4-methoxyphenyl)-2-naphthylamine, prepared
according to ref. [39]; m. p. 70 ◦C. – 1H NMR (CDCl3):
δ = 3.81, 383 (ds, 3H, OCH3), 6.93 – 9.95 (dd, J = 6.8 Hz,
2 arom. H), 7.18 (dd, J = 14.5 Hz, 1 arom. H), 7.25 (dd,
J = 4.6 Hz, 1 arom. H), 7.45 – 7.47 (m, 1 arom. H), 7.50 –
7.54 (m, 1 arom. H), 7.64, 7.78 (dd, J = 2.1 Hz, 1 arom. H),
7.77 – 7.85 (m, 2 arom. H), 7.81, 8.01 (ds, 1 arom. H), 8.65,
8.79 (ds, 1H, CH=O). – C18H15NO (277.3): calcd. C 77.96,
H 5.45, N 5.05; found C 77.81, H 5.41, N 5.18.
Preparation of N,N-diaryl-substituted formamides 1 (Gen-
eral procedure)
All the formamides studied were prepared by refluxing of
a mixture of an appropriate diarylamine (10 mmol) in formic
acid (25 mL) for 6 h and subsequent removing the formic
acid at a rotary evaporator in vacuo. Solid products were re-
crystallized from toluene/hexane, and liquid products were
purified by vacuum distillation using a microdistiller.
N,N-Bis(1-naphthyl)formamide (1k)
From N,N-bis-(1-naphthyl)amine; m. p. 210 ◦C.
–
1H NMR (CDCl3): δ = 7.32 – 7.40 (m, 2 arom. H), 7.44 –
7.47 (m, 2 arom. H), 7.54 – 7.64 (m, 4 arom. H), 7.81 – 7.88
(m, 2 arom. H), 7.92 – 7.94 (m, 2 arom. H), 8.10 – 8.18 (m, 2
arom. H), 8.85 (s, 1H, CH=O). – C21H15NO (297.1): calcd.
C 84.82, H 5.08, N 4.71; found C 84.38, H 4.89, N 4.73.
N,N-Diphenyl-formamide (1c)
From diphenylamine; m. p. 73 ◦C (ref. [33]: m. p. 71 –
◦
72 C). – 1H NMR (CDCl3): δ = 7.15 – 7.17 (m, 2 arom.
H), 7.25 – 7.32 (m, 4 arom. H), 7.37 – 7.42 (m, 4 arom. H),
8.64 (s, 1H, CH=O). – C13H11NO (197.23): calcd. C 79.16,
H 5.62, N 7.10; found C 79.16, H 5.89, N 7.16.
N-(1-Naphthyl)-N-(2-naphthyl)formamide (1l)
From N-(1-naphthyl)−N-(2-naphthyl)amine; m. p. 62 –
◦
1
65 C. – H NMR (CDCl3): δ = 7.20 (dd, J = 2.1, 7.5 Hz,
1 arom. H), 7.36 – 7.55 (m, 13 arom. H), 7.64 – 7.66 (m, 2
arom. H), 7.73 – 7. 81 (m, 8 arom. H), 7.88 – 7.90 (m, 3
N-(1-Naphthyl)-N-phenyl-formamide (1g)
From N-phenyl-1-naphthylamine; m. p. 74 ◦C. – 1H NMR arom. H), 7.93 (d, J = 7.5 Hz, 1 arom. H), 8.58, 9.09 (ds,
(CDCl3): δ = 7.16 – 7.25 (m, 2 arom. H), 7.29 – 7.34 (m, 2 2H, CH=O). – C21H15NO (297.1): calcd. C 84.82, H 5.080,
arom. H), 7.41 – 7.56 (m, 5 arom. H), 7.78, 7.85 (dd, J = N 4.71; found C 84.38, H 4.89, N 4.73.
Brought to you by | University of Georgia Libraries
Authenticated
Download Date | 5/27/15 4:45 AM

282
J. Scho¨newerk – H. Hartmann · N,N-Diaryl-substituted Formamide Chlorides
N,N-Bis(2-naphthyl)formamide (1m)
5.4 Hz, 2H, CH2), 1.38 (s, 2H, CH2), 2.05 (q, 2H, CH2), 2.29
(s, 2H, CH2), 7.26 – 7.30 (m, 2 arom. H), 6.79 (q, 1 arom. H),
8.35 (d, J = 6.8 Hz, 1 arom. H), 9.11, 9.50 (ds, 1H, CH=O). –
From N,N-bis-(2-naphthyl)amine; m. p. 124 ◦C.
–
1H NMR (CDCl3): δ = 7.19 (dd, J = 2.2, 8.8 Hz, 1 arom. H),
7.39 (dd, J = 2.1, 8.8 Hz, 1 arom. H), 7.43 – 7.47 (m, 2 arom.
H), 7.48 – 7.52 (m, 2 arom. H), 7.71 – 7.73 (m, 2 arom. H),
7.77 (d, J= 1.9 Hz, 1 arom. H), 7.79 – 7.84 (m, 5 arom. H),
8.81 (s, 1H, CH=O). – C21H15NO (297.1): calcd. C 84.82,
H 5.08, N 4.71; found C 84.69, H 5.07, N 4.73
C
13H131NO (199.3): calcd. C 78.36, H 6.58, N 7.03; found
C 79.12, H 7.14, N 7.15.
Preparation of N-dichloromethyl-N,N-diarylamines 10 (Gen-
eral procedure)
The N-dichloromethyl-N,N-diarylamines 10 were pre-
pared by the addition of oxalyl dichloride or POCl3 to a
solution of the corresponding N,N-diarylformamide 1 in
dichloromethane. After some standing at r. t. the mixture was
transferred into an NMR tube, and the 1H signals of the
formed product were recorded. The following compounds
were identified:
N-Formyl-9H-acridane (1n)
From 9H-acridane; m. p. 88 ◦C; (ref. [34]: m. p. 110 ◦C). –
1H NMR (CDCl3): δ = 4.88 (s, 2H, CH2), 7.27 – 7.33 (m, 4
arom. H), 7.73 (t, J = 3.8 Hz, 1 arom. H), 7.93 (d, J = 7.0 Hz,
1 arom. H), 8.03 (t, J = 7.4 Hz, 1 arom. H), 8.17 (d, J= 8.4 Hz,
1 arom. H), 8.88 (s, 1H, CH=O). – C14H11NO (209.2): calcd.
C 80.36, H 5.30, N 6.69; found C 80.65, H 4.39, N 6.89.
N-Dichloromethyl-N,N-diphenylamine (10c)
N-Formyl-10H-phenothiazine (1o)
1H NMR (CDCl3): δ = 7.19 – 7.25 (m, 6 arom. H), 7.35 –
From 10H-phenothiazine; m. p. 140 ◦C; (ref. [35]:
7.40 (m, 4 arom. H), 7.60 (s, 1H, CHCl2).
◦
m. p. 144 C). – 1H NMR (CDCl3): δ = 7.22 – 7.28 (m, 3
N-Dichloromethyl-N-(1-naphthyl)-N-phenylamine (10g)
arom. H), 7.31 – 7.40 (m, 4 arom. H), 7.73 (d, J= 7.4 Hz, 1
arom H), 8.65 (s, 1H, CH=O). – C13H9NOS (227.3): calcd.
C 68.70, H 3.99, N 6.16, S 14.11; found C 68.55, H 3.99,
N 6.19, S 13.98.
1H NMR (CDCl3): δ = 7.01 – 7.03 (m, 1 arom. H), 7.13 –
7.15 (m, 2 arom. H), 7.23 – 7.26 (m, 2 arom H), 7.50 – 7.55
(m, 4 arom. H), 7.57 (s, 1H, CHCl2), 7.91 – 7.96 (m, 3
arom. H).
N-Formyl-5H-dibenz[b,f]azepine (1p)
From 5H-dibenz[b,f]azepine; m. p. 128 ◦C; (ref. [36]:
N-Dichloromethyl-N-(4-methoxyphenyl)-N-(1-naphthyl)-
amine (10h)
1H NMR (CDCl3): δ = 6.79 (d, J = 9.2 Hz, 2 arom. H),
7.20 (d, J = 9.2 Hz, 2 arom. H), 7.49 – 7.53 (m, 2 arom. H),
7.62 (dd, J = 1.2, 7.3 Hz, 1 arom H), 7.65 (s, 1H, CHCl2),
7.87 – 7.91 (m, 2 arom. H), 7.96 – 7.98 (m, 1 arom. H).
◦
1
m. p. 135 – 136 C. – H NMR (CDCl3): δ = 6.86 (dd, J =
11.7 Hz, 14,6 Hz, 2 arom. H), 7.26 – 7.28 (m, 1 arom. H),
7.33 – 7.42 (m, 5 arom. H), 7.43 – 7.46 (m, 2 arom. H), 8.31
(s, 1H, CH=O). – C15H11NO (221.3): calcd. C 81.43, H 5.01,
N 6.33; found C 80.26, H 4.97, N 6.24.
N-Formyl-10,11-dihydro-5H-dibenz[b,f]azepine (1q)
N-Dichloromethyl-N-(2-naphthyl)-N-phenylamine (10i)
From
10,11-dihydro-5H-dibenz[b,f]azepine;
m. p.
1H NMR (CDCl3): δ = 7.22 – 7.25 (m, 2 arom. H), 7,27 –
7.7.29 (m, 2 arom. H), 7.38 – 7.40 (m, 2 arom. H), 7.46 –
7.50 (m, 2 arom. H), 7.71 (s, 1H, CHCl2), 7.78 – 7.85 (m, 4
arom. H).
118 ◦C; (ref. [35]: m. p. 137 ◦C). – 1H NMR (CDCl3):
δ = 2.84 – 2.95 (m, 2H, CH2), 3.39 – 3.45 (m, 2H, CH2),
7.19 – 7.28 (m, 7 arom. H), 7.35 (d, J = 3.2 Hz, 1 arom. H),
8.58 (s, 1H, CH=O). – C15H13NO (223.3): calcd. C 80.69,
H 5.87, N 6.27; found C 80.58, H 5.97, N 6.25.
N-Dichloromethyl-N-(4-methoxyphenyl)-N-(2-naphthyl)-
amine (10j)
N-Formyl-carbazole (1r)
1H NMR (CDCl3): δ = 3.83 (s, 3H, OCH3), 6.95 (dd, J =
6.7 Hz, 2 arom. H), 7.12 (dd, J = 2.4 Hz, 1 arom H), 7.71 (dd,
J = 6.7 Hz, 2 arom. H), 7.83 – 7.7.41 (m, 1 arom. H), 7.44 –
7.48 (m, 1 arom. H), 7.63 (d, J = 2.3 Hz, 1 arom. H), 7.70 (d,
J = 8.8 Hz, 1 arom. H), 7.71 (s, 1H, CHCl2), 7.75 – 7.78 (m,
2 arom. H).
From carbazole; m. p. 98 – 100 ◦C; (ref. [37]:
m. p. 94 ◦C). – 1H NMR (CDCl3): δ = 7.40 – 7.43 (m,
2 arom. H), 7.47 – 7.5 (m, 2 arom H), 7.71 (d, J = 6.5 Hz,
1 arom. H), 7.97 (s, br, 2 arom. H), 8.57 (d, J = 6.5 Hz, 1
arom. H), 9.68 (s, 1H, CH=O). – C13H9NO (195.2): calcd.
C 79.98, H 4.65, N 7.17; found C 80.33, H 4.90, N 7.32.
Dichloromethyl-di-(1-naphthyl)amine (10k)
N-Formyl-1,2,3,4-tetrahydrocarbazole (1s)
From 1,2,3,4-tetrahydrocarbazole; m. p. 63 ◦C; (ref. [38]:
1H NMR (CDCl3): δ = 7.43 – 7.49 (m, 7 arom. H), 7.76
m. p. 64 – 65 ◦C). – 1H NMR (CDCl3): δ = 1.30 (t, J = (d, J = 8.2 Hz, 4 arom. H), 7.84 (s, 1H, CHCl2), 7.85 – 7.92
Brought to you by | University of Georgia Libraries
Authenticated
Download Date | 5/27/15 4:45 AM

J. Scho¨newerk – H. Hartmann · N,N-Diaryl-substituted Formamide Chlorides
283
(m, 1 arom. H), 7.94 – 7. 96 (m, 1 arom. ), 8.10 – 8.13 (m, 1 N-Dichloromethyl-1,2,3,4-tetrahydrocarbazole (10s)
arom. H).
1H NMR (CDCl3): δ = 1.88 – 1.90 (m, 2H, CH2), 1.98 –
2.02 (m, 2H, CH2), 2.68 – 2.71 (m, 2H, CH2), 7.22 – 7.25 (m,
1 arom. H), 7.47 (d, J = 7.7 Hz, 1 arom. H), 7.81 (s, 1H,
CHCl2), 7.84 (s, br, 1 arom. H).
Dichloromethyl-(1-naphthyl)-(2-naphthyl)amine (10l)
1H NMR (CDCl3): δ = 7.11 (dd, J = 2.4, 9.2 Hz, 1 arom.
H), 7.33 – 7.36 (m, 1 arom. H), 7.40 – 7.43 (m, 1 arom. H),
7.48 – 7.57 (m, 3 arom. H), 7.63 – 7.65 (m, 2 arom. H), 7.66 Preparation of N,N’-tetraphenyl-formamidinium tetrafluo-
(s, 1H, CHCl2), 7.70 – 7.7.75 (m. 3 arom. H), 7.93 (d, J = roborate (13)
8.2 Hz, 1 arom. H), 8.00 (d, J = 7.6 Hz, 1 arom. H).
To a solution of N,N-diphenylformamide (1c, 2.0 g,
0.01 mol) in dichloromethane (25 mL) oxalyl chloride (2.5 g,
Dichloromethyl-di-(2-naphthyl)amine (10m)
0.02 mol) was added under cooling. The resulting mixture
was concentrated in vacuo after 30 min and mixed with a
1H NMR (CDCl3): δ = 7.28 (dd, J = 2.4, 8.5 Hz, 2 arom.
solution of diphenylamine (11, 1.7 g, 0.01 mol) in methanol
(25 mL). By addition of aqueous HBF4 the formamidinium
salt 13 precipitated and was isolated by filtration in a yield
of 2.0 g (45 %), m. p. 296 ◦C. – 1H NMR ([D6]DMSO):
δ = 7.15 – 7.18 (m, 5 arom. H), 7.19 – 7.22 (m, 5 arom.
H), 7.49 – 7.52 (m. 10 arom. H), 9.14 (s, 1H, N=CH–N). –
C25H21BF4N2 (436.3): calcd. C 68.83, H 4.85, N 6.42; found
C 67.88, H 4.83, N 6.38.
H), 7.45 – 7. 50 (m, 4 arom. H), 7.89 – 7.82 (m, 8 arom. H),
7.81 (s, 1H, CHCl2).
N-Dichloromethyl-9H-acridane (10n)
1H NMR (CDCl3): δ = 3.80 (s, 2H, CH2), 7.09 – 7.12 (m,
2 arom. H), 7.22 (dd, J = 0.9, 7.4 Hz, 2 arom. H), 7.27 – 7.30
(m, 2 arom. H), 7.64 (d, J = 8.1 Hz, 2 arom. H), 7.72 (s, 1H,
CHCl2).
Preparation of 4-dimethylamino-benzaldehyde (15)
N-Dichloromethyl-10H-phenothiazine (10o)
To a solution of N,N-diphenylformamide (1c, 2.0 g,
0.01 mol) in dichloromethane (25 mL) oxalyl chloride (2.5 g,
0.02 mol) was added under cooling. The resulting mixture
was concentrated in vacuo after 30 min and mixed with
N,N-dimethylaniline (12, 2.5 g, 0.02 mol). The mixture was
heated at 50 ◦C for 1 h, then poured into water, extracted with
dichloromethane (100 mL) and dried with magnesium sul-
fate. The filtered solution was concentrated and the deeply
colored residue purified by column chromatography on sil-
ica using toluene as eluent to yield 4-(dimethylamino)benz-
aldehyde in an amount of 0.8 g (53 %), m. p. 73 ◦C. –
1H NMR (CDCl3): δ = 3.00 (s, 6H, NCH3), 6.65 (d, J =
9.0 Hz, 2 arom. H), 7.69 (d, J = 9.0 Hz, 2 arom. H), 9.70 (s,
1H, CH=O).
1H NMR (CDCl3): δ = 7.13 (dt, 7.6, Hz, 1.2 Hz, 2 arom.
H), 7.25 – 7. 31 (m, 4 arom. H), 7.54 (s, 1H, CHCl2), 7.75
(dd, J = 8.2 Hz, 1.1 Hz, 2 arom. H).
5-Dichloromethyl-5H-dibenzo[b,f]azepine (10p)
1H NMR (CDCl3): δ = 6.78 (s, 2 arom. H), 7.23 – 7.27
(m, 4 arom. H), 7.25 (s, 1H, CHCl2), 7.40 – 7.42 (m, 2 arom.
H), 7.90 (dd, J = 7.9 Hz, 0.8 Hz, 2 arom. H).
5-Dichloromethyl-10,11-dihydro-5H-dibenzo[b,f]azepine
(10q)
1H NMR (CDCl3): δ = 2.80 (s, br, 2H, CH2), 3.38 (s, br,
2H, CH2), 7.16 – 7.18 (m, 4 arom. H), 7.23 – 7.27 (m, 2 arom.
H), 7.57 (s, 1H, CHCl2), 7.86 (d, J = 7.8 Hz, 2 arom. H).
[1] G. Jones, S. P. Stanforth, Org. React., Vol. 49; John Wi-
ley & Sons, London, 1997, pp. 1 – 330.
[2] A. Vilsmeier, A. Haak, Ber. Dtsch. Chem. Ges. 1927,
60, 119.
K. Junge, M. Beller, M. Drieß, Eur. J. Org. Chem.
2010, 4893 – 4901.
[6] R. Imhof, D. W. Ladner, J. M. Muchowski, J. Org.
Chem. 1977, 42, 3709 – 3713.
[3] a) H. H. Bosshard, R. Mory, H. Schmid, H. Zollinger,
Helv. Chim. Acta 1959, 42, 1653 – 1658; b) H. H.
Bosshard, H. Zollinger, Helv. Chim. Acta 1959, 42,
1659 – 1671.
[7] B. Baesner, G.-M. Petruck, H. Hagemann, E. Klauke,
DE 3044216, 1982.
[8] H. Bo¨hme, P. Sutoyo, Tetrahedron Lett. 1981, 22,
1671 – 1674.
[9] M. L. Martin, G. Ricolleau, S. Poignant, G. J. Martin,
J. Chem. Soc., Perkin Trans. 2 1976, 182 – 186.
[10] C. Rabiller, J. P. Renou, G. J. Martin, J. Chem. Soc.,
Perkin Trans. 1 1977, 536 – 541.
[4] W. Kantlehner in Comprehensive Organic Synthesis,
Vol. 6 (Eds.: B. Trost, M. Fleming), Pergamon Press,
Oxford, 1991, chapter 2.7, pp. 485 – 599.
[5] S. Enthaler, K. Schro¨der, S. Inoue, B. Eckhardt,
Brought to you by | University of Georgia Libraries
Authenticated
Download Date | 5/27/15 4:45 AM

284
J. Scho¨newerk – H. Hartmann · N,N-Diaryl-substituted Formamide Chlorides
[11] H. Mayr, A. R. Ofial, E.-U. Wu¨rthwein, N. C. Aust,
J. Am. Chem. Soc. 1997, 119, 12727 – 12733.
[12] W. Walter, R. F. Becker, Tetrahedron 1972, 28, 1705 –
1720.
444 – 445; Angew. Chem., Int. Ed. Engl. 1971, 10,
415 – 416.
[27] T. Gandhi, M. Nethaji, B. R. Jagirdar, Inorg. Chem.
2003, 42, 4798 – 4800.
[28] C. J. Borths, J. Chan, B. J. Burke, R. D. Larsen, Synlett
2009, 19, 3139 – 3142.
[29] A. Bagno, W. Kantlehner, G. Saielli, J. Phys. Org.
Chem. 2008, 21, 682 – 687.
[13] J. Oszczapowicz, M. Kuminska, J. Chem. Soc., Perkin
Trans. 2 1994, 103 – 107.
[14] A. Hamed, E. Mu¨ller, J. C. Jochims, Tetrahedron 1986,
42, 6645 – 6656.
[15] U. Pathak, L. K. Pandey, R. Tank, J. Org. Chem. 2008,
73, 2890 – 2893.
[30] H. Gross, D. Habisch, E. Gru¨ndemann, J. Prakt. Chem.
1968, 38, 190 – 198.
[31] J. C. Dyer, S. A. Evans, Jr., J. Org. Chem, 1980, 45,
5350 – 5355.
[16] F. Shibahara, R. Sugiura, T. Murai, Org. Lett. 2009, 11,
3064 – 3067.
[17] G. M. Li, R. A. Zingano, J. Chem. Soc., Perkin Trans.
1 1998, 647 – 649.
[18] L. Henriksen, Synthesis 1974, 501 – 502.
[19] J. Bethka, K. Karaghiosoff, L. A. Wessjohann, Tetrahe-
dron Lett. 2003, 44, 6911 – 6913.
[20] R. N. Loeppky, H. Yu, J. Org. Chem. 2004, 69, 3015 –
3024.
[21] G. Bencivenni, T. Lanza, R. Leardini, M. Minozzi,
D. Nanni, P. Spagnolo, G. Zanardi, J. Org. Chem. 2008,
73, 4721 – 4724.
[22] M. Segi, A. Kojima, T. Nakajima, S. Suga, Synlett
1981, 105 – 106.
[23] M. Hosseini-Sarvari, H. Sharghi, J. Org. Chem. 2006,
71, 6652 – 6654.
[24] M. Rahman, D. Kundu, A. Hajra, A. Majee, Tetrahe-
dron Lett. 2010, 51, 2896 – 2899.
[25] R. J. Abraham, J. J. Bryne, L. Griffiths, M. Perez,
Magn. Res. Chem. 2006, 44, 491 – 509.
[26] G. Gattow, R. Engler, Angew. Chem. 1971, 83,
[32] J. Leis, K. D. Klika, M. Karelson, Tetrahedron 1998,
54, 7497 – 7504.
[33] G. Olah, S. Kuhn, Chem. Ber. 1956, 89, 2211 – 2212.
[34] K. Brewster, R. A. Chitten, J. M. Harrison, T. D. Indi,
C. Brown, J. Chem. Soc., Perkin Trans. 1 1976, 1291 –
1296.
[35] U. Pindur, H. Witzel, Archiv Pharm. 1990, 323, 439 –
442.
[36] J. Querner, Dissertation, TU Dresden, Dresden, 2004.
[37] a) H. Witzel, U. Pindur, J. Heterocycl. Chem. 1988, 25,
907 – 910; b) C. Flo, U. Pindur, Liebigs Ann. Chem.
1987, 509 – 513.
[38] Y. Marakami, H. Ishii, Chem. Pharm. Bull. 1981, 29,
699 – 703.
[39] E. Knoevenagel, J. Prakt. Chem. 1914, 89, 1 – 50.
[40] K. Griesbaum, G. Zwick, Chem. Ber. 1986, 119, 229 –
243.
[41] H. E. Gottlieb, V. Kotlyar, A. Nudelman, J. Org. Chem.
1997, 62, 7512 – 7515.
Brought to you by | University of Georgia Libraries
Authenticated
Download Date | 5/27/15 4:45 AM