N-butyllithium-mediated reactions of 1-(2-azidoarylmethyl)-1H- benzotriazoles with alkyl halides

Article abstract of DOI:10.1002/jhet.275

(Chemical Equation Presented) Treatment of 1-(2-azidoarylmethyl)-1H- benzotriazoles (6) with n-BuLi (2.5 equiv.) in THF at -78°C, followed by an addition of alkyl halides such as allyl, benzyl, and ethyl bromides with stirring for 2 h at room temperature afforded 2-(dialkylamino)-3-(benzotriazol- 1-yl)-2H-indazoles (8), 3-(benzotriazol-1-yl)-2H-indazoles (9), 2-[(benzotriazol-1-yl)methyl]arylamine (10), and 2-[(benzotriazol-1-yl)(alkyl) methyl]arylamine (11).

Full text of DOI:10.1002/jhet.275

98
N-Butyllithium-Mediated Reactions of 1-(2-Azidoarylmethyl)-
1H-benzotriazoles with Alkyl Halides
Vol 47
Taehoon Kima* and Kyongtae Kimb
aKolon Life Science, Inc. 207-2, Mabuk-Dong, Giheung-gu, Yongin-si,
Gyeonggi-do, 446-797, Korea
bDepartment of Chemistry, Seoul National University, Seoul 151-742, Korea
*E-mail: kth419@unitel.co.kr
Received July 7, 2009
DOI 10.1002/jhet.275
Published online 29 December 2009 in Wiley InterScience (www.interscience.wiley.com).
Treatment of 1-(2-azidoarylmethyl)-1H-benzotriazoles (6) with n-BuLi (2.5 equiv.) in THF at ꢀ78ꢁC,
followed by an addition of alkyl halides such as allyl, benzyl, and ethyl bromides with stirring for 2 h
at room temperature afforded 2-(dialkylamino)-3-(benzotriazol-1-yl)-2H-indazoles (8), 3-(benzotriazol-
1-yl)-2H-indazoles (9), 2-[(benzotriazol-1-yl)methyl]arylamine (10), and 2-[(benzotriazol-1-yl)(alkyl)
methyl]arylamine (11).
J. Heterocyclic Chem., 47, 98 (2010).
0ꢁC or alkyllithiums in n-pentane to give alkyltriazenes
[4]. The latter reactions in ether did not occur. The reac-
tion leading to triazenes was sensitive to the solvents.
Furthermore, to the best of our knowledge, there has
been no report on the reactions of aryl azides with both
Grignard reagents and alkyllithiums. Compounds 6 are
insoluble in n-pentane at room temperature. Conse-
quently, it was necessary to obtain information on the
reactivity of aryl azides including 6 toward various
bases. The results obtained from our examination are
described herein.
INTRODUCTION
Benzotriazole has received a great amount of atten-
tion over the last three decades owing to the potential
utility as a synthetic auxiliary for the synthesis of a
diverse class of organic compounds [1]. Recently, we
reported the reactions of 3-(benzotriazol-1-yl)-2,3-disub-
stituted propenyl phenyl sulfoxides 3 [2], prepared from
1-(arylmethyl)-1H-benzotriazoles 2a and 1-aryl-2-chlor-
oethanone in five steps, with trifluoroacetic anhydride
(TFAA) yielding triazapentalenes 4 via a Pummerer-
type intramolecular nucleophilic attack of N-2 of the
benzotriazole moiety [2a] (Scheme 1).
In connection with the exploration of the synthetic
utility of 1, the introduction of an alkyl group at the
benzylic position of 1-(2-azidoarylmethyl)-1H-benzotria-
zoles 6 (R2 ¼ 2-N3) was attempted simply because the
azido group may be utilized as a precursor for genera-
tion of nitrene [3]. Nitrene is known as a useful reactive
species for the synthesis of nitrogen-containing hetero-
cyclic compounds via insertion or addition reactions.
One can envisage the reaction of a benzylic carbanion,
generated from compounds 6 by a strong base, with
alkyl halides. However, a problem to be encountered
with this methodology is to overcome the possible reac-
tion of the azido group with the strong base. A search
through the literature showed that simple alkyl azides
reacted with both Grignard reagents in diethyl ether at
RESULTS AND DISCUSSION
2-Azidobenzyl bromides 5 (R2 ¼ 2-N3, X ¼ Br), pre-
cursors of 1-(2-azidoarylmethyl)-1H-benzotriazoles 6a-
b, 6d-e, and 6g, were prepared by diazotization of o-to-
luidine derivatives, followed by bromination of the
methyl group using NBS in the presence of benzoyl per-
oxide [5b]. On the other hand, 2-azidobenzyl chloride 5
(R2 ¼ 2-N3, X ¼ Cl), precursors of compounds 6c and
6f, were prepared by diazotization of 2-aminobenzyl
alcohols, followed by chlorination using SOCl2 in
CH2Cl2. Treatment of 5 with benzotriazoles 1a-b in the
presence of NaOEt in absolute ethanol [6] gave a mix-
ture of 6 and 2-(2-azidoarylmethyl)-2H-benzotriazoles 7
which were separated by chromatography (Scheme 2).
C
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January 2010 n-Butyllithium-Mediated Reactions of 1-(2-Azidoarylmethyl)-1H-benzotriazoles with
Alkyl Halides
99
Scheme 1
Table 1
Yields of compounds 6 and 7.
Yielda
(%)
Compd
R
R1
R2
X
Compd
6
7
1a
1a
1a
1a
1a
1a
1a
1a
1b
H
H
H
H
H
H
H
H
Cl
H
5-MeO
3-Me
5-Br
4-Cl
5-Cl
5-NO2
H
2-N3
2-N3
2-N3
2-N3
2-N3
2-N3
2-N3
4-N3
2-N3
Br
Br
Cl
Br
Br
Cl
Br
Br
Br
a
b
c
d
e
f
g
h
i
50
44
55
47
51
48
42
47
44b
19
19
16
22
26
23
18
20
19
Yields of compounds 6 and 7 are summarized in
Table 1.
H
Treatment of 6a with n-BuLi (1.1 equiv.) in THF at
ꢀ78ꢁC, followed by addition of allyl bromide (1.1
equiv.) with stirring for 1 h did not reveal any new spots
except for those of the starting materials on TLC. How-
ever, after being stirred at room temperature for 2 h,
TLC of the reaction mixture showed four spots includ-
ing that corresponding to 6a (Rf ¼ 0.71, EtOAc:n-hex-
ane ¼ 1:4). Chromatography of the reaction mixture
(silica gel, 70–230 mesh) gave two 2H-indazole deriva-
tives 8a (R ¼ R1 ¼ H) (25%), 9a (R ¼ R1 ¼ H) (21%),
2-[(benzotriazol-1-yl)methyl]phenylamine (10a) (R ¼ R1
¼ H) (25%) and 2-[1-(benzotriazol-1-yl)-3-butenyl]phe-
nylamine (11a) (R ¼ R1 ¼ H) (0%) together with
unreacted 6a (24%) containing a minute amount of 1-
a Isolated yields.
b Total yield of 1-(2-azidobenzyl)-5-chloro-1H-benzotriazole (6i0) and
1-(2-azidobenzyl)-6-chloro-1H-benzotriazole (6i).
spectrum showed a singlet at 3.24 ppm, corresponding
to the structure of 13.
[(2-azidophenyl)(allyl)methyl]-1H-benzotriazole
(12a)
(Scheme 3). The yield of each product was variable
depending on the concentrations of n-BuLi and allyl
bromide. The results are summarized in Table 2.
On addition of allyl bromide (1.1 equiv.), compound 8a
was obtained in 20% yield at the expense of 6a and 10a
(entry 2). The amounts of recovered 6a as well as 8a
were decreased somewhat by two-fold increase of the
concentration of n-BuLi only (entry 3). When the con-
centrations of n-BuLi and allyl bromide were increased
two-fold, respectively (entry 4), the yield of 8a
increased to 38% at the expense of 9a and 6a. However,
further increase in the concentration of n-BuLi (4.0
equiv.) while maintaining the same concentration of
Table 2 shows that compounds 9a and 10a were
formed without allyl bromide and a considerable amount
of 6a (40%) remained unreacted when 1.0 molar equiv.
of n-BuLi was employed (entry 1). The result is incon-
sistent with the formation of dialkyltriazenes from anal-
ogous reactions involving simple alkyl azides and alkyl-
lithiums in n-pentane [4a]. However, the reaction of 6a
with MeMgBr in THF for 1 h at 0ꢁC, and subsequently
at room temperature for 2 h, gave methyltriazene 13
(91%) as expected. The 1H NMR (300 MHz, CDCl3)
Scheme 3
Scheme 2. Reagents and conditions: For X ¼ Br, (i) 1a (or 1b),
NaOEt, absolute EtOH, rt, 12 h; For X ¼ Cl, (i) 1a, NaOEt, absolute
EtOH, reflux, 5 h.
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100
T. Kim and K. Kim
Vol 47
Table 2
Yields of compounds 8a-11a at the different concentrations of n-BuLi and allyl bromide when [6a] ¼ 1.40 mmol.
Yielda (%)
Entry
n-BuLi (equiv.)
Allyl bromide (equiv.)
8a
9a
10a
11a
Unreacted (6a)
1
2
3
4
5
1.0
1.1
2.0
2.5
4.0
0
0
20
15
38
39
24
21
17
15
13
37
25
28
5
0
0
40
1.1
1.1
2.2
2.2
24b
18b
13b
5b
0
18
25
0
a Isolated yields.
b Yields on the basis of the 1H NMR intensities of a mixture of 6a and 12a.
allyl bromide (2.2 equiv.), did not affect the yields of
8a and 9a but only reduced the amount of unreacted 6a
by 5% (entry 5). Finally, the amount of unreacted 6a
decreased with increase in the concentration of n-BuLi
and yet the yield of 8a did not exceed 39%. In addition,
the yields of 9a were not much affected by altering the
concentrations of either n-BuLi or allyl bromide.
Since the yields of compound 11a increased with the
concentrations of n-BuLi and allyl bromide (entries 4
and 5) and the sum of the yields of 10a and 11a
appeared nearly constant, 10a, prepared independently
from 6a and NaBH4 [7], was treated with allyl bromide
(2.5 and 3.0 equiv.) in the presence of n-BuLi (2.5 and
3.0 equiv.) in THF for 1 h at 0ꢁC, and subsequently at
room temperature for 2 h to observe if compound 11a is
formed via compound 10a. From the reactions were
obtained 11a (0 and 3%), allyl[2-{(benzotriazol-1-yl)me-
thyl}phenyl]amine (14) (38 and 16%), diallyl[2-{(benzo-
triazol-1-yl)methyl}phenyl]amine (15) (33 and 41%),
various bases under the same foregoing conditions. The
results are summarized in Table 3.
Table 3 showed that not only a considerable amount
of 6a was used up to give unidentifiable mixtures but
also a large quantity of unreacted 6a was recovered.
Consequently, n-BuLi was employed as a base for reac-
tions of other compounds 6. Yields of 8–11 and
unreacted 6 are summarized in Table 4.
The structure of 8 was determined on the basis of the
X-ray crystal structure of 8g (Fig. 1).
The structures of 9 were determined on the basis of
spectroscopic and analytical data. In particular, the
HMBC spectrum of 9a shows that the N2-H proton cor-
relates with C3a and C7a carbon atoms, which clearly
indicates that the compound is 2H-indazole derivative
[8] rather than 1H-indazole derivative.
To obtain mechanistic information, 6h was subjected
to the same foregoing conditions (Scheme 5). From the
reaction were obtained allylated compound 19 (4%) and
amino compound 20 (45%) together with unreacted 6h
(28%). The result indicated that reduction of the azido
group yielding amino group occurs readily compared
with allylation at the benzylic position.
and
allyl[2-{1-(benzotriazol-1-yl)-3-butenyl}phenyl]-
amine (16) (5 and 17%), respectively (Scheme 4). Com-
pounds 14–16 were not detected in the reaction of 6a
under similar conditions but compound 11a was
observed (Scheme 4).
Although there exist plentiful examples of the direct
conversion of an azido group to an amino group [9], n-
BuLi-mediated the same type of conversion has seldom
appeared in the literature [10]. We have found that treat-
ment of simple aryl azides with n-BuLi (2.0 equiv.)
under the same foregoing conditions gave arylamine as
The result indicates that a small portion of compound
11a may be formed via 10a. For optimization of the
reaction conditions, the reactions of 6a (1.25 mmol)
with allyl bromide were carried out in the presence of
Scheme 4
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January 2010 n-Butyllithium-Mediated Reactions of 1-(2-Azidoarylmethyl)-1H-benzotriazoles with
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101
Table 3
Yields of compounds 8a, 9a, 10a, and unreacted 6a.
Yieldb (%)
Base (equiv.)
Conditiona
8a
9a
10a
6a
c
d
g
tert-BuLi (1.5)
NaH (1.5)
0
0
15
5
0
0
12
0
trace
0
25
0
82
75
21
81
41
33
c
NaNH2 (1.5)
n-BuLi (1.5)
KN(SiMe3)2 (1.5)
LDA (1.5)
c,e
c
c,f
c
6
9
8
15
15
13
LDA (1.2)
a Allyl bromide (1.5 equiv.) was used.
b Isolated yields.
c
ꢀ78ꢁC (1 h) ! rt (2 h), THF.
d rt (5 h), THF.
Figure 1. ORTEP drawing of 8g. [Color figure can be viewed in the
online issue, which is available at www.interscience.wiley.com.]
e n-BuLi, followed by tert-BuOK (1.0 equiv.) was added.
f LDA, followed by TMEDA (1.0 equiv.) was added.
g Unidentifiable complex mixture.
major compounds (Scheme 6). Product yields are sum-
marized in Table 5.
tion occurs under the conditions where the azido group
is intact. Of course, compounds analogous to 8 and 9
cannot be formed from the reaction of 6h. Interest-
ingly, the reaction of 6a with a mixture of an equal
The formation of 19 coupled with 12c as minor
product indicates that alkylation at the benzylic posi-
Table 4
Yields of compounds 8a, 9a, 10a, and unreacted 6a.
Reactant
Product, Yielda (%)
Compd (R)
R3
Compd
8 (R1)
9 (R1)
10 (R1)
11 (R1)
6 (R1)
6a (H)
6a (H)
6a (H)
6a (H)
6a (H)
6a (H)
6b (H)
6c (H)
6d (H)
6e (H)
6f (H)
6g (H)
6i (Cl)
CH2CH¼CH2
Et
a
b
c
d
e
f
g
h
i
38 (H)
25 (H)
14 (H)
13 (H)
2 (H)
21 (H)
19 (H)
0 (H)
3 (H)
trace (H)
0 (4)b (H)
4 (H)
CH2CH2CH¼CH2
0 (0)b (H)
31 (H)
0 (H)
16 (21)b (H)
16 (H)
18 (H)
20 (14)b (H)
5 (H)
0 (H)
4 (0)b,c
6 (H)
Bn
n-Bu
13d (H)
0 (H)
3e (4-MeO)
5e (6-Me)
4e (4-Br)
6e (5-Cl)
8e (4-Cl)
0 (H)
31 (H)
tert-Bu
0 (H)
21 (H)
14 (H)
CH2CH¼CH2
CH2CH¼CH2
CH2CH¼CH2
CH2CH¼CH2
CH2CH¼CH2
CH2CH¼CH2
CH2CH¼CH2
24 (5-MeO)
34 (7-Me)
26 (5-Br)
26 (6-Cl)
28 (5-Cl)
19 (5-MeO)
13 (7-Me)
14 (5-Br)
16 (6-Cl)
17 (5-Cl)
8 (4-MeO)
10 (6-Me)
7 (4-Br)
5 (5-Cl)
3 (5-MeO)
trace (3-Me)
2 (5-Br)
2 (4-Cl)
4 (5-Cl)
j
k
2 (4-Cl)
f
l
30 (H)
12 (H)
6 (H)
0 (H)
2 (H)
a Isolated yields.
b All data were obtained when alkyl bromides (X ¼ Br) were used. Number in the parenthesis represents yields when iodide was used.
c When CH2¼CHCH2CH2Br was used, compounds 12c (R ¼ R1 ¼ H, R3 ¼ CH2CH2CH¼CH2) and 17 were additionally isolated in 18 and 3%
yields, respectively, whereas only 12c was additionally isolated in 13% yield when CH2¼CHCH2CH2I was used.
d When n-BuBr was used, compound 18 was additionally isolated in 11% yield.
e Yields calculated on the basis of the intensities of the 1H NMR spectra of a mixture of 10 and 11.
f Unidentifiable complex mixtures were obtained when R1 ¼ 5-NO2.
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T. Kim and K. Kim
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Scheme 5
molar amount of allyl bromide (1.2 equiv.) and benzyl
bromide (1.2 equiv.) under the same foregoing condi-
tions showed four spots on TLC (silica gel, EtOAc:n-
hexane ¼ 1:4), corresponding to 8d (Rf ¼ 0.79), a mix-
ture of 8a and 23 (Rf ¼ 0.70), 9a (Rf ¼ 0.42), and 10a
(Rf ¼ 0.27) along with a weak spot having a long tail
(Scheme 7).
[12] and that the equilibrium position between tautomers
is dependent on the solvent polarity. However, molecu-
lar mechanics calculations show that 8g (E ¼ 35.75
kcal/mol) is more stable than its 1H-isomer (E ¼ 38.54
kcal/mol) by 2.79 kcal/mol [13]. Similarly, 2H-indazole
9a (E ¼ 29.75 kcal/mol) is more stable than its 1H-in-
dazole isomer (E ¼ 33.70 kcal/mol) by 3.95 kcal/mol.
This tendency is consistent with the experimental
results. Further study is necessary to delineate why 2H-8
and 2H-9 are more stable than 1H-8 and 1H-9, respec-
tively. A nucleophilic attack of the carbanion 24 on allyl
bromide would give 12a, analogous to 19. A similar
reaction of 12a as shown in the formation of 10a from
27a would give 11a.
An attempt at separation of the mixture of 8a and 23
was unsuccessful. However, FAB MS shows mass num-
ber (m/z) 331 (Mþ þ 1) and 381 (Mþ þ 1), correspond-
ing to the molecular weight of 8a and 23 plus one,
respectively. The formation of 23 suggests that the R3
of compounds 8 is introduced in a stepwise manner.
The formation of compound 8a may be initiated by
deprotonation of benzylic hydrogen to give a carbanion
24, followed by an intramolecular nucleophilic attack of
the carbanion on the tetravalent nitrogen atom of an azido
group, leading to a five-membered intermediate 25 with a
negative charge on each nitrogen atom (Scheme 8).
Monoalkylation of 25 gives 1,3-dipolar intermediate
26a, which is stabilized by a resonance form 26b. Sub-
sequent allylation, followed by deprotonation would
give 8a. In the meantime, a nucleophilic attack of n-
butyl carbanion on an azido group gives 1-n-butyl-3-
phenyltriazene 27a [4], which may be stabilized by a
resonance form 27b. Intramolecular proton transfer of
27a would generate a carbanion 28. Protonation of 28,
followed by decomposition would give 10a or 17 [11].
Alternatively, compounds 10a and 17 can be formed
from intermediate 27 via the same protonation and
decomposition processes. In contrast, intramolecular
nucleophilic attack of the benzylic carbanion 29, a tau-
tomer of 28, on the trivalent nitrogen concomitant with
displacing the n-butylamide ion would lead to 30, a tau-
tomer of 9a and 31. However, we obtained 9a as a sin-
gle compound. It has been reported that 1H-indazoles
are thermodynamically more stable than 2H-indazoles
CONCLUSION
In summary, when 1-(2-azidoarylmethyl)-1H-benzo-
triazoles (6) was treated with n-BuLi in THF at ꢀ78ꢁC,
followed by an addition of alkyl halides, i.e., allyl, ben-
zyl, ethyl bromides, TLC did not exhibit any new spots.
On the other hand, four new spots corresponding to 2H-
indazole derivatives 8 and 9, which to the best of our
knowledge had not been previously reported in the reac-
tions of azido compounds, together with some weak
spots, were observed at room temperature. Compounds
8 are envisaged to be formed by a nucleophilic attack of
benzylic carbanion on the azido group, followed by dis-
placement of halides twice in stepwise manner by the
SN2 mechanism. Compounds 9 would be formed by a
nucleophilic attack of benzylic carbanion on triazenes.
The formation of compounds 10 and 11 may be
Table 5
Yields of compounds 21 and 22.
Yielda (%)
Compd
R4
R5
21
22
a
b
c
H
Me
Et
Me
H
69
76
69
72
8
6
8
7
Scheme 6
H
H
d
Bz
a Isolated yields.
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January 2010 n-Butyllithium-Mediated Reactions of 1-(2-Azidoarylmethyl)-1H-benzotriazoles with
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103
Scheme 7. Reaction of 6a with the mixture of an equal molar amount of allyl bromide and benzyl bromide.
Scheme 8. Proposed mechanism of formation to the compounds 8, 9, 10, 11, and 17.
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2-(2-Azidophenylmethyl)-2H-benzotriazole 7a. Mp 114–
116ꢁC (from EtOAc–n-hexane) (Found: C, 62.35; H, 3.9; N,
33.7. Calc. for C13H10N6: C, 62.4; H, 4.0; N, 33.6%); mmax
(KBr)/cmꢀ1 3056, 2936, 2104, 1577, 1489, 1444, 1283, 1158,
explained in terms of decomposition of triazene, which
has been reported in the literature [5].
1
1084, 851, 745, and 530; H NMR d 5.86 (2H, s, CH2), 7.05
EXPERIMENTAL
(1H, t, J 7.5, ArH), 7.12 (1H, d, J 7.5, ArH), 7.21 (1H, d, J
7.6, ArH), 7.28 (1H, d, J 7.7, ArH), 7.33 (2H, dd, J 6.6 and
3.1, ArH), and 7.86 (2H, dd, J 6.6 and 3.1, ArH); 13C NMR d
55.6, 118.6, 118.7, 125.4, 126.2, 126.8, 130.4, 130.9, 138.7,
and 144.7.
1
The H NMR spectra was recorded at 300 MHz, unless oth-
erwise stated in CDCl3 solution containing tetramethylsilane as
internal standard: J values are given in hertz (Hz). The 13C
NMR spectra were recorded at 75 MHz, unless otherwise
stated in CDCl3 solution. IR spectra were recorded in KBr or
thin-film samples on KBr plates. Mass spectra were obtained
by electron impact at 70 eV. Elemental analyses were deter-
mined by the National Center for Inter-University Research
Facilities, Seoul National University. Column chromatography
was performed using silica gel (Merck, 70-230 mesh ASTM).
Mps were determined on a Fisher–Johns melting-point appara-
tus and are uncorrected.
1-[(2-Azido-5-methoxy)phenylmethyl]-1H-benzotriazole 6b. Mp
89–91ꢁC (from EtOAc–n-hexane) (Found: C, 56.1; H, 4.3; N,
30.1. Calc. for C14H12N6O: C, 56.0; H, 4.3; N, 30.0%); mmax
(KBr)/cmꢀ1 3056, 2930, 2824, 2108, 1603, 1494, 1446, 1424,
1
1281, 1236, 1155, 1078, 1032, 811, 744, and 521; H NMR d
3.67 (3H, s, OCH3), 5.77 (2H, s, CH2), 6.67 (1H, d, J 2.8, 1H,
ArH), 6.88 (1H, dd, J 8.8 and 2.8, ArH), 7.12 (1H, d, J 8.8,
ArH), 7.36 (1H, t, J 7.1, ArH), 7.45 (1H, t, J 6.8, ArH), 7.55
(1H, d, J 8.3, ArH), and 8.06 (1H, J 8.3 Hz, ArH); 13C NMR
d 47.3, 56.0, 110.3, 115.4, 116.0, 119.8, 120.4, 124.4, 127.4,
127.9, 130.4, 133.2, 146.5, and 157.4.
General procedure for the synthesis of 2-azidoarylmethyl
halides 5
2-Azidoarylmethyl bromides 5a-b, 5d-e, and 5g-h. To a
stirred solution of arylamine (32.80 mmol) in concentrated
H2SO4 (6 mL) was added NaNO2 (39.36 mmol) at 0ꢁC. The
mixture was stirred for 30 min, followed by addition of NaN3
(55.76 mmol), which was additionally stirred for 24 h. Work-
up according to the literature procedure [5a] gave substituted
2-azidotoluenes. A mixture of 2-azidotoluene, N-bromosuccini-
mide (NBS) (1.05 equiv.) and benzoyl peroxide (0.05 equiv.)
in benzene (60 mL) was heated at reflux for 24 h [5b]. Usual
work-up of the reaction mixture gave 5a-b (73, 87%), 5d-e
(79, 64%), and 5g (89%), respectively. Similarly, 4-azidoben-
zyl bromide (5h) was prepared from 4-azidotoluene in 90%
yield.
2-Azidoarylmethyl chlorides 5c and 5f. To a stirred solu-
tion of substituted 2-aminoarylmethyl alcohols (32.80 mmol)
in concentrated H2SO4 (6 mL) was added NaNO2 (39.36
mmol) at 0ꢁC for 30 min, followed by addition of NaN3
(55.76 mmol). The mixture was additionally stirred for 24 h,
followed by usual work-up gave substituted 2-azidoaryl-
methyl alcohol. Treatment of 2-azidoarylmethyl alcohols
with thionyl chloride [5c] (1.2 equiv.) at 0ꢁC for 3 h gave 5c
(63%) and 5f (62%).
General procedure for the synthesis of 1-(2-azidoaryl-
methyl)-1H-benzotriazoles 6 and 2-(2-azidoarylmethyl)-2H-
benzotriazoles 7. To a stirred solution of sodium (5.65–8.82
mmol) in absolute ethanol (20 mL) was added a solution of
benzotriazole (1a) (5.38–8.40 mmol) in absolute ethanol
(30 mL). The mixture was stirred for 20 min, followed by
addition of 5 (5.65–8.82 mmol), which was heated for 3.5 h at
reflux. Work-up according to the literature procedure [6] gave
compounds 6 and 7. Yields are listed in Table 1.
2-[(2-Azido-5-methoxy)phenylmethyl]-2H-benzotriazole 7b. Mp
102–104ꢁC (from EtOAc–n-hexane) (Found: C, 56.2; H, 4.3;
N, 29.9. Calc. for C14H12N6O: C, 56.0; H, 4.3; N, 30.0%);
mmax (KBr)/cmꢀ1 3048, 2936, 2824, 2112, 1603, 1556, 1489,
1454, 1424, 1281, 1236, 1161, 1030, 841, 746, 624, and 521;
1H NMR d 3.71 (3H, s, OCH3), 5.85 (2H, s, CH2), 6.79 (1H,
d, J 2.9, ArH), 6.90 (1H, dd, J 8.8 and 2.9, ArH), 7.11 (1H, d,
J 8.8, ArH), 7.37 (2H, dd, J 6.6 and 3.1, ArH), and 7.88 (2H,
dd, J 6.6 and 3.1, ArH); 13C NMR d 55.6, 56.0, 115.9, 116.2,
118.6, 119.8, 126.9, 127.1, 131.0, 144.9, and 157.3.
1-[(2-Azido-3-methyl)phenylmethyl]-1H-benzotriazole 6c. Mp
54–56ꢁC (from EtOAc–n-hexane) (Found: C, 63.55; H, 4.5; N,
31.9. Calc. for C14H12N6: C, 63.6; H, 4.6; N, 31.8%); mmax
(KBr)/cmꢀ1 3048, 2936, 2104, 1606, 1585, 1454, 1427, 1340,
1286, 1220, 1153, 1084, 774, 740, and 520; 1H NMR d 2.42
(3H, s, CH3), 5.86 (2H, s, CH2), 6.91 (1H, d, J 7.1, ArH), 6.99
(1H, t, J 7.6, ArH), 7.10 (1H, d, J 7.4, ArH), 7.32 (1H, dt, J
1.3 and 6.7, ArH), 7.37–7.49 (2H, m, ArH), and 8.04 (1H, d, J
8.3, ArH); 13C NMR d 18.3, 48.6, 110.1, 120.3, 124.3, 126.7,
127.7, 127.8, 128.8, 132.3, 133.3, 133.5, 136.5, and 146.5.
2-[(2-Azido-3-methyl)phenylmethyl]-2H-benzotriazole 7c. Vis-
cous liquid (Found: C, 63.5; H, 4.5; N, 31.95. Calc. for
C14H12N6: C, 63.6; H, 4.6; N, 31.8%); mmax (KBr)/cmꢀ1 3040,
2948, 2110, 1607, 1585, 1454, 1420, 1342, 1286, 1221, 1150,
1
1084, 845, 746, and 521; H NMR d 2.48 (3H, s, CH3), 5.99
(2H, s, CH2), 7.06–7.11 (2H, m, ArH), 7.15–7.19 (1H, m,
ArH), 7.38 (2H, dd, J 6.6 and 3.1, ArH), and 7.89 (2H, dd, J
6.6 and 3.1, ArH); 13C NMR d 18.5, 56.9, 118.6, 126.7, 126.8,
128.5, 128.8, 132.5, 133.6, 137.2, and 145.0.
1-[(2-Azido-5-bromo)phenylmethyl]-1H-benzotriazole 6d. Mp
84–86ꢁC (from EtOAc–n-hexane) (Found: C, 47.3; H, 2.8; N,
25.45. Calc. for C13H9BrN6: C, 47.4; H, 2.8; N, 25.5%); mmax
(KBr)/cmꢀ1 3056, 2948, 2110, 1574, 1482, 1441, 1302, 1288,
1-(2-Azidophenylmethyl)-1H-benzotriazole 6a. Mp 97–99ꢁC
(from EtOAc–n-hexane) (Found: C, 62.3; H, 3.95; N, 33.7.
Calc. for C13H10N6: C, 62.4; H, 4.0; N, 33.6%); mmax (KBr)/
cmꢀ1 3040, 2944, 2112, 1572, 1480, 1441, 1302, 1278, 1216,
1
1217, 1154, 1073, 752, 740, and 521; H NMR d 5.77 (2H, s,
CH2), 7.09 (1H. d, J 8.5, ArH), 7.27 (1H, d, J ¼ 2.1, ArH),
7.37–7.43 (1H, m, ArH), 7.46–7.56 (3H, m, ArH), and 8.10
(1H, d, J 8.3, ArH); 13C NMR d 46.8, 109.9, 118.5, 120.3,
120.6, 124.5, 128.1, 133.2, 133.3, 137.5, and 146.5.
2-[(2-Azido-5-bromo)phenylmethyl]-2H-benzotriazole 7d. Mp
94–96ꢁC (from EtOAc–n-hexane) (Found: C, 47.25; H, 2.9; N,
25.5. Calc. for C13H9BrN6: C, 47.4; H, 2.8; N, 25.5%); mmax
1
1152, 1073, 752, 739, and 523; H NMR d 5.83 (2H, s, CH2),
7.05–7.16 (2H, m, ArH), 7.22 (1H, d, J 8.0, ArH), 7.34–7.41
(2H, m, ArH), 7.46 (1H, dd, J 8.3 and 1.0, ArH), 7.53 (1H, d,
J 7.2, ArH) and 8.08 (1H, d, J 8.3, ArH); 13C NMR d 47.4,
110.2, 118.7, 120.4, 124.3, 125.6, 126.3, 126.4, 127.8, 130.3,
133.3, 138.3, and 146.5.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

January 2010 n-Butyllithium-Mediated Reactions of 1-(2-Azidoarylmethyl)-1H-benzotriazoles with
Alkyl Halides
105
(KBr)/cmꢀ1 3056, 2942, 2110, 1575, 1480, 1444, 1302, 1289,
5.94 (2H, s, CH2), 7.34 (1H, d, J 8.8, ArH), 7.42 (2H, dd, J
6.6 and 3.1, ArH), 7.88 (2H, dd, 6.6 and 3.1, ArH), 8.17 (1H,
d, J 2.5, ArH), and 8.28 (1H, dd, J 8.8 and 2.5, ArH); 13C
NMR d 55.0, 118.6, 119.2, 125.9, 126.7, 127.1, 127.2, 144.9,
145.1, and 145.4.
1-(4-Azidophenylmethyl)-1H-benzotriazole 6h. Mp 90–92ꢁC
(from EtOAc–n-hexane) (Found: C, 62.5; H, 4.0; N, 33.7.
Calc. for C13H10N6: C, 62.4; H, 4.0; N, 33.6%); mmax (KBr)/
cmꢀ1 3048, 2944, 2112, 1600, 1571, 1494, 1438, 1297, 1214,
1147, 1081, 822, 776, 758, 740, and 524; 1H NMR d 5.83
(2H, s, CH2), 7.00 (2H, d, J 8.5, ArH), 7.29 (2H, d, J 8.5,
ArH), 7.33–7.46 (3H, m, ArH), and 8.08 (1H, d, J 9.0, ArH);
13C NMR d 52.0, 109.9, 120.0, 120.6, 124.4, 127.9, 129.6,
131.8, 133.1, 140.8, and 146.8.
2-(4-Azidophenylmethyl)-2H-benzotriazole 7h. Mp 108–
110ꢁC (from EtOAc–n-hexane) (Found: C, 62.45; H, 3.9; N,
33.7. Calc. for C13H10N6: C, 62.4; H, 4.0; N, 33.6%); mmax
(KBr)/cmꢀ1 3048, 2924, 2110, 1601, 1573, 1495, 1438, 1280,
1210, 1147, 1081, 822, 774, 740, and 518; 1H NMR d 5.87
(2H, s, CH2), 7.01 (2H, d, J 8.4, ArH), 7.30 (2H, d, J 8.4,
ArH), 7.38 (2H, dd, J 6.6 and 3.1, ArH), and 7.89 (2H, dd, J
6.6 and 3.1, ArH); 13C NMR d 58.4, 111.4, 120.2, 124.5,
126.6, 130.3, 138.7, and 146.1.
1
1218, 1156, 1074, 754, 739, and 521; H NMR d 5.85 (2H, s,
CH2), 7.09 (1H. d, J 8.6, ArH), 7.38 (1H, d, J ¼ 2.2, ArH),
7.42 (2H, dd, 6.6 and 3.1, ArH), 7.50 (1H, dd, 8.5 and 2.2,
ArH), and 7.90 (2H, dd, 6.6 and 3.1, ArH); 13C NMR d 55.1,
118.3, 118.6, 120.3, 127.1, 127.9, 133.5, 133.7, 138.0, and
145.0.
1-[(2-Azido-4-chloro)phenylmethyl]-1H-benzotriazole 6e. Mp
72–74ꢁC (from EtOAc–n-hexane) (Found: C, 54.9; H, 3.1; N,
29.4. Calc. for C13H9ClN6: C, 54.8; H, 3.2; N, 29.5%); mmax
(KBr)/cmꢀ1 3048, 2952, 2112, 1572, 1480, 1444, 1302, 1278,
1210, 1160, 1074, 756, and 516; 1H NMR d 5.77 (2H, s,
CH2), 7.06 (2H, s, ArH), 7.20 (1H, s, ArH), 7.37–7.42 (1H, m,
ArH), 7.45–7.54 (2H, m, ArH), and 8.08 (1H, d, J 8.3, ArH);
13C NMR d 46.8, 110.0, 118.9, 120.5, 124.5, 124.8, 125.9,
128.0, 131.4, 133.2, 135.9, 139.6, and 146.5.
2-[(2-Azido-4-chloro)phenylmethyl]-2H-benzotriazole 7e. Mp
80–82ꢁC (from EtOAc–n-hexane) (Found: C, 54.8; H, 3.15; N,
29.3. Calc. for C13H9ClN6: C, 54.8; H, 3.2; N, 29.5%); mmax
(KBr)/cmꢀ1 3048, 2947, 2112, 1575, 1489, 1441, 1302, 1268,
1
1211, 1160, 1084, 756, 642, and 516; H NMR d 5.85 (2H, s,
CH2), 7.10 (1H, dd, J 8.2 and 1.9, ArH), 7.20 (1H, d, J 1.9,
ArH), 7.21 (1H, d, J 8.2, ArH), 7.41 (2H, dd, J 6.6 and 3.1,
ArH), and 7.88 (2H, dd, J 6.6 and 3.1, ArH); 13C NMR d
55.1, 118.5, 119.0, 124.6, 125.8, 127.0, 123.1, 136.2, 140.1,
and 145.0.
Reaction of 5-chlorobenzotriazole (1b) with 2-azidoben-
zyl bromide (5a). In accordance with the aforementioned gen-
eral procedure, 5a (1770 mg, 8.34 mmol) was added to a mix-
ture of 1b (1220 mg, 7.94 mmol) and Na (183 mg, 8.34
mmol) in absolute ethanol (50 mL). The mixture was stirred
for 12 h at room temperature. After removal of the solvent in
vacuo, the residue was chromatographed on a silica gel (3.0 ꢂ
15 cm2) using a mixture of EtOAc and n-hexane (1:5) to give
2-(2-azidophenylmethyl)-2H-(5-chlorobenzotriazole) (7i) (407
mg, 18%), a mixture of 1-(2-azidophenylmethyl)-6-chloro-1H-
benzotriazole (6i) and 1-(2-azidophenylmethyl)-5-chloro-1H-
benzotriazole (6i0) (995 mg, 44%) and unreacted 1b. The mix-
ture of 6i and 6i0 (1:1 based on the 1H NMR signal of CH2)
was separated by the repeated recrystallization using a mixture
of EtOAc and n-hexane (1:15) to give 6i and 6i0 as solids.
6i. Mp 77–79ꢁC (from EtOAc–n-hexane) (Found: C, 54.7;
H, 3.1; N, 29.5. Calc. for C13H9ClN6: C, 54.8; H, 3.2; N,
29.5%); mmax (KBr)/cmꢀ1 3056, 2952, 2848, 2112, 1575, 1481,
1-[(2-Azido-5-chloro)phenylmethyl]-1H-benzotriazole 6f. Mp
97–99ꢁC (from EtOAc–n-hexane) (Found: C, 54.7; H, 3.2; N,
29.6. Calc. for C13H9ClN6: C, 54.8; H, 3.2; N, 29.5%); mmax
(KBr)/cmꢀ1 3052, 2952, 2829, 2110, 1576, 1442, 1306, 1281,
1
1224, 1156, 1077, 904, 742, and 520; H NMR d 5.77 (2H, s,
CH2), 7.11 (1H, s, ArH), 7.15 (1H, dd, J 8.6 and 2.7, ArH),
7.32–7.43 (2H, m, ArH), 7.47–7.54 (2H, m, ArH), and 8.09
(1H, d, J 7.7, ArH); 13C NMR d 46.9, 109.9, 119.9, 120.6,
124.5, 128.0, 128.1, 130.2, 130.4, 131.1, 133.2, 136.9, and
146.5.
2-[(2-Azido-5-chloro)phenylmethyl]-2H-benzotriazole 7f. Mp
113–115ꢁC (from EtOAc–n-hexane) (Found: C, 54.8; H, 3.1;
N, 29.65. Calc. for C13H9ClN6: C, 54.8; H, 3.2; N, 29.5%);
mmax (KBr)/cmꢀ1 3054, 2952, 2828, 2112, 1580, 1444, 1307,
1281, 1224, 1156, 1078, 905, 746, and 516; 1H NMR d 5.82
(2H, s, CH2), 7.06 (1H, d, J 8.6, ArH), 7.19 (1H, d, J 2.4,
ArH), 7.28 (1H, dd, J 8.6 and 2.4, ArH), 7.36 (2H, dd, J 6.6
and 3.1, ArH), and 7.87 (2H, dd, J 6.6 and 3.1, ArH); 13C
NMR d 55.1, 118.6, 119.9, 127.0, 127.7, 130.4, 130.7, 130.8,
137.3, and 145.0.
1-[(2-Azido-5-nitro)phenylmethyl]-1H-benzotriazole 6g. Mp
144–146ꢁC (from EtOAc–n-hexane) (Found: C, 52.9; H, 3.1;
N, 10.7. Calc. for C13H9N7O2: C, 52.85; H, 3.1; N, 10.8%);
mmax (KBr)/cmꢀ1 3064, 3024, 2112, 1603, 1574, 1504, 1476,
1331, 1281, 1214, 1148, 1081, 824, 768, 736, and 526; 1H
NMR d 5.84 (2H, s, CH2), 7.34 (1H, d, J 8.8, ArH), 7.37–7.43
(1H, m, ArH), 7.48–7.56 (2H, m, ArH), 8.03 (1H, d, J 2.5,
ArH), 8.09 (1H, d, J 8.3, ArH), and 8.24 (1H, dd, J 8.8 and
2.6, ArH); 13C NMR d 46.9, 109.6, 119.2, 120.7, 124.7, 125.8,
126.0, 127.5, 128.3, 133.2, 145.0, 145.1, and 146.4.
2-[(2-Azido-5-nitro)phenylmethyl]-2H-benzotriazole 7g. Mp
171–173ꢁC (from EtOAc–n-hexane) (Found: C, 53.0; H, 3.2;
N, 10.7. Calc. for C13H9N7O2: C, 52.85; H, 3.1; N, 10.8%);
mmax (KBr)/cmꢀ1 3058, 3026, 2112, 1605, 1578, 1506, 1476,
1334, 1280, 1148, 1080, 824, 768, 624, and 526; 1H NMR d
1
1440, 1302, 1278, 1206, 1155, 1074, 740, and 518; H NMR d
5.78 (2H, s, CH2), 7.07–7.17 (2H, m, ArH), 7.27 (1H, d, J 8.0,
ArH), 7.33 (1H, dd, J 8.7 and 1.5, ArH), 7.40 (1H, td, J 7.5
and 2.0, ArH), 7.53 (1H, d, J 1.7, ArH), and 7.99 (1H, d, J
8.8, ArH); 13C NMR d 47.6, 110.1, 118.8, 121.4, 125.6, 125.7,
125.8, 130.4, 130.6, 133.9, 134.3, 138.4, and 145.1.
6i0. Mp 116–118ꢁC (from EtOAc–n-hexane) (Found: C,
54.9; H, 3.0; N, 29.4. Calc. for C13H9ClN6: C, 54.8; H, 3.2; N,
29.5%); mmax (KBr)/cmꢀ1 3048, 2954, 2110, 1572, 1488, 1444,
1
1302, 1278, 1201, 1160, 1074, 756, 642, and 516; H NMR d
5.80 (2H, s, CH2), 7.10–7.18 (2H, m, ArH), 7.22 (1H, d, J 7.9,
ArH), 7.39 (1H, d, J 1.4, ArH), 7.42 (1H, d, J 1.7, ArH), 7.46
(1H, s, ArH), and 8.04 (1H, d, J 1.7, ArH); 13C NMR d 47.7,
111.3, 118.8, 119.7, 125.7, 128.8, 130.3, 130.4, 130.5, 130.6,
131.9, 138.4, and 147.1.
7i. Mp 102–104ꢁC (from EtOAc–n-hexane) (Found: C,
54.9; H, 3.1; N, 29.3. Calc. for C13H9ClN6: C, 54.8; H, 3.2; N,
29.5%); mmax (KBr)/cmꢀ1 3050, 2952, 2112, 1574, 1480, 1441,
1
1308, 1280, 1200, 1157, 1065, 756, 648, and 520; H NMR d
5.88 (2H, s, CH2), 7.14 (1H, td, J 7.7 and 1.5, ArH), 7.34 (1H,
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

106
T. Kim and K. Kim
Vol 47
dd, J 9.1 and 1.9, ArH), 7.42 (1H, td, J 8.0 and 1.5, ArH),
7.82 (1H, d, J 1.9, ArH), and 7.88 (1H, d, J 1.6, ArH); 13C
NMR d 55.9, 117.6, 118.8, 119.8, 125.5, 125.7, 128.4, 130.7,
131.0, 132.7, 138.9, 143.4, and 145.2.
1228, 1153, 996, 918, 740, and 520; 1H NMR d 3.24–3.31
(1H, m, CH2), 3.40–3.51 (1H, m, CH2), 4.02 (2H, s, NH2),
5.02 (1H, d, J 14.3, ¼¼CH2), 5.07 (1H, d, J 20.6, ¼¼CH2),
5.68–5.82 (1H, m, ¼¼CH), 6.09 (1H, dd, J 9.2 and 6.5, CH),
6.65 (1H, d, J 8.0, ArH), 6.84 (1H, t, J ¼ 7.6, ArH), 7.14 (1H,
dt, J 1.4 and 7.7, ArH), 7.28–7.39 (2H, m, ArH), 7.41–7.48
(2H, m, ArH), and 8.05 (1H, d, J ¼ 7.4, ArH); 13C NMR d
36.5, 60.8, 110.8, 117.6, 118.8, 119.2, 120.5, 124.4, 127.7,
128.0, 130.1, 132.6, 133.6, 145.8, and 147.0.
Reaction of 6a with ethyl bromide. In accordance with the
aforementioned general procedure, a mixture of 6a (500 mg,
2.00 mmol), ethyl bromide (545 mg, 5.00 mmol), and n-BuLi
(5.00 mmol) was stirred. Chromatography of the reaction mix-
ture gave 2-(N,N-diethylamino)-3-(benzotriazol-1-yl)-2H-inda-
zole (8b) (153 mg, 25%), 9a (66 mg, 13%), and 10a (94 mg,
21%).
General procedure for the reactions of 6 with alkyl hal-
ides in the presence of n-BuLi. To a solution of 6 (1.80
mmol) in THF (40 mL) at –78ꢁC were added n-BuLi (2.5M in
n-hexane, 4.50 mmol) and alkyl halide (4.50 mmol), which
was stirred for 1 h. The mixture was additionally stirred for 2
h at room temperature, quenched by addition of water (30 mL)
and extracted with CH2Cl2 (20 mL ꢂ 3). The combined
extract was dried over MgSO4. Evaporation of the solvent in
vacuo gave a residue, which was chromatographed on a silica
gel (2.5 ꢂ 13 cm2) using a mixture of EtOAc and n-hexane
(1:6) to give 2-(N,N-dialkylamino)-3-(benzotriazol-1-yl)-2H-
indazoles 8, 3-(benzotriazol-1-yl)-2H-indazole 9, 2-[(benzotria-
zol-1-yl)methyl]arylamines 10, 2-[(benzotriazol-1-yl)(alkyl)me-
thyl]arylamines 11, and unreacted 6.
Reaction of 6a with allyl bromide. In accordance with the
aforementioned general procedure, a mixture of 6a (350 mg,
1.40 mmol), allyl bromide (423 mg, 3.50 mmol), and n-BuLi
(3.50 mmol) was stirred. Chromatography of the reaction
mixture gave 2-(N,N-diallylamino)-3-(benzotriazol-1-yl)-2H-
indazole (8a) (176 mg, 38%), 3-(benzotriazol-1-yl)-2H-inda-
zole (9a) (46 mg, 14%), 2-[(benzotriazol-1-yl)methyl]phenyl-
amine (10a) (6 mg, 2%), 2-[1-(benzotriazol-1-yl)-3-butenyl]-
phenylamine (11a) (70 mg, 19%), and unreacted 6a (11 mg,
3%).
8b. Viscous liquid (Found: C, 66.7; H, 6.1; N, 27.25. Calc.
for C17H18N6: C, 66.65; H, 5.9; N, 27.4%); mmax (film)/cmꢀ1
3048, 2960, 2856, 1606, 1526, 1444, 1371, 1275, 1206, 1081,
1
1038, 1000, 966, 938, and 739; H NMR d 0.83 (6H, t, J 7.1,
CH3), 3.27 (4H, d, J 6.2, CH2), 7.15–7.21 (1H, m, ArH), 7.30
(2H, d, J 8.5, ArH), 7.42–7.56 (3H, m, ArH), 7.83 (1H, d, J
8.9, ArH), and 8.23 (1H, d, J 7.8, ArH); 13C NMR d (DMSO)
12.6, 52.7, 110.1, 115.9, 118.6, 118,8, 120.8, 124.3, 124.9,
127.5, 129.2, 135.3, 145.6, and 145.7.
Reaction of 6a with 4-bromo-1-butene. In accordance with
the aforementioned general procedure, a mixture of 6a (400
mg, 1.60 mmol), 4-bromo-1-butene (540 mg, 4.00 mmol), and
n-BuLi (4.00 mmol) was stirred for 1 h at ꢀ78ꢁC and 2 h at
room temperature. Chromatography of the reaction mixture
gave 9a (31 mg, 16%), 10a (72 mg, 20%), 2-[1-(benzotriazol-
1-yl)-4-pentenyl]phenylamine (11c) (18 mg, 4%), 1-[1-(2-azi-
dophenyl)-4-pentenyl]-1H-benzotriazole (12c) (88 mg, 18%),
8a. Mp 89–91ꢁC (from n-hexane) (Found: C, 68.95; H, 5.5;
N, 25.4. Calc. for C19H18N6: C, 69.1; H, 5.5; N, 25.4%); mmax
(KBr)/cmꢀ1 3056, 2912, 2848, 1630, 1601, 1555, 1523, 1440,
1398, 1371, 1280, 1227, 1200, 1166, 1033, 990, 924, 836,
1
740, and 516; H NMR d 3.86 (4H, d, J 6.6, CH2), 4.96 (2H,
[2-{1-(benzotriazol-1-yl)-4-pentenyl}phenyl]butylamine
(14 mg, 3%).
(17)
J 17.4, ¼¼CH2), 5.01 (2H, d, J 24.7, ¼¼CH2), 5.49–5.65 (2H,
m, ¼¼CH), 7.08–7.16 (1H, m, ArH), 7.23–7.31 (2H, m, ArH),
7.33–7.41 (1H, m, ArH), 7.43–7.57 (2H, m, ArH), 7.79 (1H, d,
J 8.9, ArH), and 8.20 (1H, d, J 7.9, ArH); 13C NMR d 60.8,
110.4, 115.7, 118.7, 118.8, 120.5, 120.7, 124.3, 125.0, 127.4,
129.1, 132.8, 135.1, 145.4, and 145.7.
9a. Mp 219–220ꢁC (CH2Cl2–n-hexane) (Found: C, 66.3; H,
3.8; N, 29.8. Calc. for C13H9N5: C, 66.4; H, 3.9; N, 29.8%);
mmax (KBr)/cmꢀ1 3136, 3040, 2928, 2880, 1609, 1523, 1488,
1436, 1385, 1342, 1273, 1244, 1166, 1094, 1003, 984, 918,
892, and 737; 1H NMR d (DMSO) 7.34 (1H, t, J 7.8, ArH),
7.52–7.62 (2H, m, ArH), 7.66–7.79 (2H, m, ArH), 8.25 (2H, d,
J 8.3, ArH), 8.37 (1H, d, J 8.4, ArH), and 13.6 (1H, s, NH);
13C NMR d (DMSO) 111.8, 113.7, 115.0, 120.5, 121.8, 122.9,
126.2, 128.8, 130.0, 132.1, 140.3, 142.1, and 145.9.
10a. Mp 111–113ꢁC (from EtOAc–n-hexane) (Found: C,
69.5; H, 5.3; N, 25.05. Calc. for C13H12N4: C, 69.6; H, 5.4; N,
25.0%); mmax (KBr)/cmꢀ1 3352, 3232, 3056, 2912, 1627, 1601,
1577, 1488, 1446, 1299, 1262, 1219, 1152, 1006, 740, and
521; 1H NMR d 4.32 (2H, s, NH2), 5.74 (2H, s, CH2), 6.67
(1H, d, J 7.9, ArH), 6.77 (1H, t, J 7.5, ArH), 7.14 (1H, t, J
7.8, ArH), 7.29–7.36 (2H, m, ArH), 7.42 (1H, t, J 6.8, ArH),
7.53 (1H, d, J 8.3, ArH), and 8.04 (1H, d, J 8.3, ArH); 13C
NMR d 50.6, 110.4, 117.2, 118.7, 118.9, 120.4, 124.5, 126.3,
128.0, 130.7, 131.1, 133.1, and 146.5.
11c. Viscous liquid (Found: C, 73.6; H, 6.4; N, 19.9. Calc.
for C17H18N4: C, 73.35; H, 6.5; N, 20.1%); mmax (film)/cmꢀ1
3434, 3226, 3048, 2924, 1604, 1487, 1441, 1308, 1272, 1220,
1154, 996, 740, and 520; 1H NMR d 1.97–2.21 (2H, m,
CHCH2CH2), 1.38–1.50 (1H, m, CHCH2CH2), 2.89–3.01 (1H,
m, CHCH2CH2), 4.95 (1H, d, J 17.1, ¼¼CH2), 5.03 (1H, d, J
10.1, ¼¼CH2), 5.76–5.89 (1H, m, ¼¼CH), 6.20 (1H, dd, J 9.4
and 5.7, CH), 7.10 (1H, dt, J 1.0 and 7.3, ArH), 7.18 (1H, dd,
J 8.0 and 1.0, ArH), 7.25–7.38 (2H, m, ArH), 7.42–7.51 (2H,
m, ArH), 7.57 (1H, d, J 8.3, ArH), and 8.07 (1H, d, J 8.3,
ArH); 13C NMR d 30.9, 34.3, 56.1, 110.2, 116.5, 118.4, 120.3,
124.4, 125.9, 127.6, 128.6, 129.9, 131.1, 133.7, 137.1, 137.4,
and 146.2.
12c. Viscous liquid (Found: C, 67.2; H, 5.2; N, 27.4. Calc.
for C17H16N6: C, 67.1; H, 5.3; N, 27.6%); mmax (film)/cmꢀ1
3056, 2928, 2848, 2112, 1675, 1632, 1601, 1483, 1443, 1264,
1211, 1153, 1070, 993, 910, 743, 696, and 523; 1H NMR d
2.03–2.15 (2H, m, CHCH2CH2), 2.50–2.62 (1H, m,
CHCH2CH2), 2.88–3.01 (1H, m, CHCH2CH2), 4.98 (1H, d, J
17.0, ¼¼CH2), 5.04 (1H, d, J 10.2, ¼¼CH2), 5.75–5.91 (2H, m,
¼¼CH and CH), 7.25–7.40 (7H, m, ArH), and 8.07 (1H, d, J
8.0, ArH); 13C NMR d 30.9, 34.3, 63.0, 110.2, 116.7, 120.4,
124.3, 127.3, 127.6, 128.7, 129.3, 133.3, 137.2, 139.6, and
146.6.
11a. Viscous liquid (Found: C, 72.6; H, 6.0; N, 21.35. Calc.
for C16H16N4: C, 72.7; H, 6.1; N, 21.2%); mmax (film)/cmꢀ1
3432, 3344, 3224, 3056, 2920, 1624, 1486, 1446, 1304, 1265,
17. Viscous liquid (Found: C, 75.5; H, 7.65; N, 16.8. Calc.
for C21H26N4: C, 75.4; H, 7.8; N, 16.75%); mmax (film)/cmꢀ1
3264, 3056, 2936, 2856, 1630, 1603, 1475, 1440, 1392, 1198,
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

January 2010 n-Butyllithium-Mediated Reactions of 1-(2-Azidoarylmethyl)-1H-benzotriazoles with
Alkyl Halides
107
1
993, 910, 740, and 518; H NMR d 1.03 (3H, t, J 7.3, CH3),
1.45–1.57 (2H, m, NCH2CH2CH2CH3), 1.69–1.72 (2H, m,
NCH2CH2CH2CH3), 2.01–2.14 (2H, m, CHCH2CH2), 2.48–
2.59 (1H, m, CHCH2CH2), 2.91–3.06 (1H, m, CHCH2CH2),
3.76 (2H, t, J 7.1, NCH2), 4.93 (1H, d, J 17.7, ¼¼CH2), 4.98
(1H, d, J 10.5, ¼¼CH2), 5.73–5.90 (2H, m, ¼¼CH and CH),
6.82 (1H, t, J ¼ 7.2, NH), 7.13 (1H, t, J 6.9, ArH), 7.23 (1H,
t, J 7.4, ArH), 7.29–7.51 (5H, m, ArH), and 8.06 (1H, d, J 7.7,
ArH); 13C NMR d 14.3, 20.9, 31.1, 33.0, 34.5, 44.6, 56.3,
110.6, 116.1, 120.1, 124.3, 127.0, 127.2, 127.3, 128.0, 129.0,
129.4, 133.8, 137.7, and 146.3.
1.27–1.44 (4H, m, CHCH2CH2CH2CH3), 1.45–1.56 (2H, m,
NCH2CH2CH2CH3), 1.69–180 (2H, m, NCH2CH2CH2CH3),
2.40–2.51 (1H, m, CHCH2CH2CH2CH3), 2.77–2.90 (1H, m,
CHCH2CH2CH2CH3), 3.76 (2H, dt, J 3.4 and 7.0, NCH2),
6.72 (1H, t, J 6.9, NH), 7.12 (1H, dt, J 1.1 and 7.4, ArH), 7.24
(1H, dt, J 1.4 and 7.9, ArH), 7.31–7.49 (5H, m, ArH), and
8.05 (1H, d, J 7.3, ArH); 13C NMR d 14.2, 14.3, 20.7, 22.7,
29.2, 32.1, 35.1, 44.0, 57.3, 110.5, 117.2, 120.1, 124.1, 127.0,
127.1, 127.3, 128.9, 133.8, and 146.3.
Reaction of 6a with tert-butyl bromide. In accordance
with the aforementioned general procedure, a mixture of 6a
(350 mg, 1.40 mmol), tert-butyl bromide (480 mg, 3.50
mmol), and n-BuLi (3.50 mmol) was stirred. Chromatography
of the reaction mixture gave 9a (69 mg, 21%), 10a (60 mg,
14%), and unreacted 6a (109 mg, 31%).
Reaction of 6b with allyl bromide. In accordance with the
aforementioned general procedure, a mixture of 6b (400 mg,
1.43 mmol), allyl bromide (432 mg, 3.58 mmol), and n-BuLi
(3.58 mmol) was stirred. Chromatography of the reaction
mixture gave 2-(N,N-dibenzylamino)-3-(benzotriazol-1-yl)-5-
methoxy-2H-indazole (8g) (124 mg, 24%), 3-(benzotriazol-1-
yl)-5-methoxy-2H-indazole (9g) (72 mg, 19%), [2-(benzotria-
zol-1-yl)methyl-4-methoxy]phenylamine (10g) (29 mg. 8%), [2-
{1-(benzotriazol-1-yl)-3-butenyl}-4-methoxy]phenylamine (11g)
(13 mg, 3%), and unreacted 6b (12 mg, 3%).
Reaction of 6a with 4-iodo-1-butene. In accordance with
the aforementioned general procedure, a mixture of 6a (350
mg, 1.40 mmol), 4-iodo-1-butene (644 mg, 3.50 mmol), and n-
BuLi (3.50 mmol) was stirred for 1 h at ꢀ78ꢁC and 2 h at
room temperature. Chromatography of the reaction mixture
gave 9a (68 mg, 21%), 10a (44 mg, 14%), 12c (55 mg, 13%),
and unreacted 6a (14 mg, 4%).
Reaction of 6a with benzyl bromide. In accordance with
the aforementioned general procedure, a mixture of 6a (320
mg, 1.28 mmol), benzyl bromide (547 mg, 3.20 mmol), and n-
BuLi (3.20 mmol) was stirred. Chromatography of the reaction
mixture gave 2-(N,N-dibenzylamino)-3-(benzotriazol-1-yl)-2H-
indazole (8d) (171 mg, 31%), 9a (48 mg, 16%), 10a (14 mg,
5%),
2-[{1-(benzotriazol-1-yl)-2-phenyl}ethyl]phenylamine
(11d) (24 mg, 6%), and unreacted 6a (13 mg, 4%).
8g. Mp 151–153ꢁC (from EtOAc–n-hexane) (Found: C,
66.7; H, 5.5; N, 23.3. Calc. for C20H20N6O: C, 66.65; H, 5.6;
N, 23.3%); mmax (KBr)/cmꢀ1 3064, 2936, 2848, 1638, 1600,
1558, 1499, 1446, 1278, 1212, 1036, 926, 809, 742, and 521;
1H NMR d 3.69 (3H, s, OCH3), 3.83 (4H, d, J 7.6, CH2), 4.99
(2H, d, J 10.1, ¼¼CH2), 5.04 (2H, d, J 17.2, ¼¼CH2), 5.47–5.62
(2H, m, ¼¼CH), 6.43 (1H, d, J 2.2, ArH), 7.09 (1H, dd, J 9.4,
2.4, ArH), 7.32 (1H, d, J 6.7, ArH), 7.46–7.59 (2H, m, ArH),
7.69 (1H, d, J 9.4, ArH), and 8.23 (1H, d, J 8.1, ArH); 13C
NMR d 55.8, 60.8, 110.5, 116.0, 120.3, 120.4, 120.8, 122.7,
124.9, 126.3, 128.9, 132.9, 135.2, 141.9, and 145.7.
8d. Mp 115–117ꢁC (from EtOAc–n-hexane) (Found: C,
75.25; H, 5.0; N, 19.6. Calc. for C27H22N6: C, 75.3; H, 5.15;
N, 19.5%); mmax (KBr)/cmꢀ1 3040, 2912, 2848, 1628, 1595,
1555, 1524, 1486, 1446, 1396, 1372, 1278, 1227, 1198, 1166,
1
1030, 904, 739, 694, and 520; H NMR d 4.49 (4H, s, CH2),
6.52 (1H, d, J 8.3, ArH), 6.99–7.21 (11H, m, ArH), 7.29–7.36
(2H, m, ArH), 7.41–7.47 (2H, m, ArH), 7.89 (1H, d, J 8.9,
ArH), 8.22 (1H, d, J 8.3, ArH); 13C NMR d 61.5, 110.4,
114.9, 118.7, 118.8, 120.3, 124.1, 124.8, 127.5, 128.2, 128.7,
129.6, 134.5, 136.2, 145.4, and 145.5.
1
11d. Viscous liquid (mixed with 10a); H NMR d 4.28 (2H,
Crystal data for 8g. C20H20N6O, M ¼ 360.42, triclinic, a ¼
s, NH2), 4.50 (2H, d, J 5.0, CH2), 6.18 (1H, dd, J 8.2 and 4.9,
CH), 6.53 (1H, d, J 8.3, ArH), 7.09–7.46 (10H, m, ArH), 8.06
(1H, d, J 8.3, ArH), and 8.43 (1H, d, J 8.3, ArH).
Reaction of 6a with n-butyl bromide. In accordance with
the aforementioned general procedure, a mixture of 6a (350
mg, 1.40 mmol), n-butyl bromide (480 mg, 3.50 mmol), and
n-BuLi (3.50 mmol) was stirred. Chromatography of the reac-
tion mixture gave 9a (59 mg, 18%), 2-[1-(benzotriazol-1-
yl)pentyl]phenylamine (11e) (51 mg, 13%), [2-{1-(benzotria-
zol-1-yl)pentyl}phenyl]butylamine (18) (50 mg, 11%).
11e. Viscous liquid (Found: C, 72.6; H, 7.3; N, 19.9. Calc.
for C17H20N4: C, 72.8; H, 7.2; N, 20.0%); mmax (film)/cmꢀ1
3048, 2928, 2856, 1600, 1577, 1483, 1448, 1368, 1264, 1214,
1155, 774, 739, 694, and 518; 1H NMR d 0.89 (3H, t, J 7.2,
CH3), 1.24–1.37 (4H, m, CH2CH2CH2CH3), 2.45–2.56 (1H, m,
CHCH2), 2.74–2.87 (1H, m, CHCH2), 4.05 (2H, s, NH2), 5.80
(1H, dd, J 9.0 and 6.5, CH), 7.29–7.40 (7H, m, ArH), and 8.07
(d, J 8.0, ArH); 13C NMR d 14.3, 22.7, 29.2, 34.9, 64.2,
110.3, 120.4, 124.3, 126.3, 127.3, 127.5, 128.6, 128.8, 129.3,
133.2, 139.8, and 146.6.
˚
8.009(3), b ¼ 8.019(2), c ¼ 14.760(8) A, a ¼ 81.91(5), b ¼
3
ꢁ
˚
82.16(4), c ¼ 96.01(3) , U ¼ 928.5(7) A , T ¼ 293(2) K,
space group P-1, Z ¼ 2, l(Mo-Ka) ¼ 0.085 mmꢀ1, k ¼
˚
0.71070 A, 3266 reflections measured, 3265 unique (Rint
¼
0.0029) which were used in all calculations. The final wR(F2)
was 0.1110. CCDC 212914.
9g. Mp 234–236ꢁC (from CH2Cl2–n-hexane) (Found: C,
63.4; H, 4.0; N, 26.3. Calc. for C14H11N5O: C, 63.4; H, 4.2;
N, 26.4%); mmax (KBr)/cmꢀ1 3130, 3048, 2928, 1632, 1609,
1525, 1478, 1431, 1386, 1344, 1273, 1167, 1094, 984, 918,
892, and 740; 1H NMR d (DMSO) 3.85 (3H, s, OCH3), 7.19
(1H, dd, J 9.1 and 2.2, ArH), 7.54–7.63 (3H, m, ArH), 7.73
(1H, t, J 7.3, ArH), 8.24 (1H, d, J 8.3, ArH), 8.32 (1H, d, J
8.3, ArH), and 13.5 (1H, s, NH); 13C NMR d (DMSO) 56.3,
100.0, 113.0, 113.7, 115.2, 120.4, 121.2, 126.1, 129.9, 132.1,
138.0, 139.7, 145.8, and 155.9.
1
10g. Viscous liquid (mixed with 11g); H NMR d 3.65 (3H,
s, OCH3), 4.29 (2H, s, NH2), 5.78 (2H, s, CH2), 6.65 (1H, d, J
2.9, ArH), 6.84 (1H, d, J 8.9, ArH), 7.31–7.58 (4H, m, ArH),
and 8.08 (1H, d, J 8.3, ArH).
18. Viscous liquid (Found: C, 67.2; H, 5.2; N, 27.4. Calc.
for C21H28N4: C, 67.1; H, 5.3; N, 27.6%); mmax (film)/cmꢀ1
3385, 3056, 2928, 2850, 1601, 1578, 1473, 1446, 1392, 1193,
1
11g. Viscous liquid (mixed with 10g); H NMR d 3.20–3.29
(1H, m, CH2), 3.36–3.48 (1H, m, CH2), 3.62 (3H, s, OCH3),
4.10 (2H, s, NH2), 5.04 (1H, d, J 11.7, ¼¼CH2), 5.11 (1H, d, J
19.1, ¼¼CH2), 5.61–5.77 (1H, m, ¼¼CH), 6.10 (1H, dd, J 9.3
1
1153, 1086, 774, 740, and 521; H NMR d 0.88 (3H, t, J 6.8,
CHCH2CH2CH2CH3), 1.02 (3H, t, J 7.3, NCH2CH2CH2CH3),
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

108
T. Kim and K. Kim
Vol 47
and 6.1, CH), 6.58 (1H, d, J 8.8, ArH), 7.10–7.59 (m, 5H,
ArH), and 8.11 (1H, d, J 8.2, ArH).
ArH), 7.48 (1H, s, ArH), 7.52 (1H, d, J 7.7, ArH), 7.57 (1H,
d, J ¼ 8.8, ArH), and 8.23 (1H, d, J 8.1, ArH); 13C NMR d
60.8, 110.2, 116.8, 118.0, 120.6, 120.7, 120.8, 120.9, 124.6,
129.3, 131.3, 132.6, 135.0, 143.7, and 145.7.
Reaction of 1-[(2-azido-3-methyl)phenylmethyl]benzotria-
zole (6c) with allyl bromide. In accordance with the afore-
mentioned general procedure, a mixture of 6c (350 mg,
1.32 mmol), allyl bromide (399 mg, 3.30 mmol), and n-BuLi
(3.30 mmol) was stirred. Chromatography of the reaction
mixture gave 2-(N,N-dibenzylamino)-3-(benzotriazol-1-yl)-7-
methyl-2H-indazole (8h) (168 mg, 34%), 3-(benzotriazol-1-yl)-
7-methyl-2H-indazole (9h) (43 mg, 13%), [2-(benzotriazol-1-
yl)methyl-6-methyl]phenylamine (10h) (32 mg, 10%), [2-{1-
(benzotriazol-1-yl)-3-butenyl}-6-methyl]phenylamine (11h) (18
mg, 5%).
9i. Mp 260–262ꢁC (from CH2Cl2–n-hexane) (Found: C,
49.6; H, 2.6; N, 22.35. Calc. for C13H8BrN5: C, 49.7; H, 2.6;
N, 22.3%); mmax (KBr)/cmꢀ1 3140, 3056, 2930, 2889, 1612,
1541, 146, 1381, 1339, 1241, 1165, 1089, 984, 918, 892, 737,
1
and 642; H NMR d (DMSO) 7.59 (1H, t, J 7.4, ArH), 7.66–
7.72 (2H, m, ArH), 7.77 (1H, t, J 7.3, ArH), 8.26 (1H, d, J
8.3, ArH), 8.36 (1H, d, J 8.3, ArH), 8.42 (1H, s, ArH), and
13.8 (1H, s, NH); 13C NMR d (DMSO) 113.7, 114.0, 115.0,
116.3, 120.6, 124.0, 126.3, 130.2, 131.6, 131.9, 140.8, and 145.9.
1
8h. Mp 123–125ꢁC (from EtOAc–n-hexane) (Found: C,
69.6; H, 5.9; N, 24.5. Calc. for C20H20N6: C, 69.75; H, 5.85;
N, 24.4%); mmax (KBr)/cmꢀ1 3056, 2904, 2840, 1627, 1604,
1547, 1505, 1443, 1371, 1280, 1233, 1168, 1038, 990, 924,
10i. Viscous liquid (mixed with 11i); H NMR d 4.32 (2H,
br, NH2), 5.77 (2H, s, CH2), 7.10–7.62 (6H, m, ArH), and
8.11 (1H, d, J 8.3, ArH).
11i. Viscous liquid (mixed with 10i); H NMR d 3.21–3.30
1
1
(1H, m, CH2), 3.35–3.49 (1H, m, CH2), 4.25 (2H, br, NH2),
5.01 (1H, d, J 10.8, ¼¼CH2), 5.07 (1H, d, J 18.2, ¼¼CH2),
5.65–5.81 (1H, m, ¼¼CH), 6.60 (1H, dd, J 9.1 and 6.0, CH),
7.10–7.62 (6H, m, ArH), and 8.17 (1H, d, J 8.2, ArH).
864, 747, and 521; H NMR d 2.71 (3H, s, CH3), 3.89 (4H, d,
J 6.6, CH2), 4.97 (2H, d, J 10.1, ¼¼CH2), 5.05 (2H, d, J 17.1,
¼¼CH2), 5.52–5.66 (2H, m, ¼¼CH), 7.01–7.17 (3H, m, ArH),
7.31 (1H, d, J 7.8, ArH), 7.47–7.58 (2H, m, ArH), and 8.22
(1H, d, J 7.9, ArH); 13C NMR d 17.2, 60.7, 110.5, 115.6,
116.0, 120.2, 120.7, 124.5, 124.9, 126.2, 128.9, 129.0, 133.1,
135.2, 145.6, and 145.7.
Reaction of 1-[(2-azido-4-chloro)phenylmethyl]benzotria-
zole (6e) with allyl bromide. In accordance with the afore-
mentioned general procedure, a mixture of 6e (480 mg, 1.69
mmol), allyl bromide (512 mg, 4.23 mmol), and n-BuLi (4.23
mmol) was stirred. Chromatography of the reaction mixture
gave 2-(N,N-dibenzylamino)-3-(benzotriazol-1-yl)-6-chloro-2H-
indazole (8j) (160 mg, 26%), 3-(benzotriazol-1-yl)-6-chloro-
2H-indazole (9j) (73 mg, 16%), [2-(benzotriazol-1-yl)methyl-
5-chloro]phenylamine (10j) (22 mg, 5%), [2-{1-(benzotriazol-
1-yl)-3-butenyl}-5-chloro]phenylamine (11j) (30 mg, 6%), and
unreacted 6e (10 mg, 2%).
9h. Mp 210–212ꢁC (from CH2Cl2–n-hexane) (Found: C,
67.6; H, 4.6; N, 28.0. Calc. for C14H11N5: C, 67.5; H, 4.45; N,
28.1%); mmax (KBr)/cmꢀ1 3144, 3056, 2928, 1606, 1516, 1440,
1344, 1270, 1246, 1176, 1153, 1097, 1035, 852, 779, 737, and
521; 1H NMR d (DMSO) 2.61 (3H, s, CH3), 7.23 (1H, t, J
7.9, ArH), 7.32 (1H, d, J 6.8, ArH), 7.58 (1H, t, J 7.9, ArH),
7.76 (1H, t, J 7.8, ArH), 8.05 (1H, d, J 8.1, ArH), 8.25 (1H, d,
J 8.3, ArH), 8.35 (1H, d, J 8.3, ArH), and 13.7 (1H, s, NH);
13C NMR d (DMSO) 17.4, 113.7, 114.9, 119.1, 120.5, 121.7,
123.2, 126.1, 128.4, 130.0, 132.1, 140.5, 142.2, and 145.9.
8j. Mp 80–82ꢁC (from CH2Cl2–n-hexane) (Found: C, 62.5;
H, 4.6; N, 23.2. Calc. for C19H17ClN6: C, 62.55; H, 4.7; N,
23.0%); mmax (KBr)/cmꢀ1 3064, 2908, 2848, 1630, 1608, 1518,
1473, 1443, 1374, 1280, 1195, 1163, 1043, 992, 928, 851,
1
10h. Viscous liquid (mixed with 11h); H NMR d 2.14 (3H,
s, CH3), 4.28 (2H, s, NH2), 5.79 (2H, s, CH2), 6.73 (1H, t, J
7.5, ArH), 7.08 (1H, d, J 7.2, ArH), 7.24–7.61 (4H, m, ArH),
and 8.06 (1H, d, J 8.3, ArH).
1
744, and 520; H NMR d 3.85 (4H, d, J 6.7, CH2), 4.98 (2H,
d, J 10.1, ¼¼CH2), 5.04 (2H, d, J 17.1, ¼¼CH2), 5.48–5.62 (2H,
m, ¼¼CH), 7.12 (1H, dd, J 8.9, 1.7, ArH), 7.22–7.31 (2H, m,
ArH), 7.48–7.60 (2H, m, ArH), 7.80 (1H, d, J 1.3, ArH), and
8.23 (1H, d, J 8.1, ArH); 13C NMR d 60.8, 110.3, 114.0,
117.8, 120.1, 120.7, 120.9, 125.1, 125.8, 125.9, 129.3, 132.6,
133.6, 135.0, 145.4, and 145.7.
1
11h. Viscous liquid (mixed with 10h); H NMR d 2.19 (3H,
s, CH3), 4.06 (2H, s, NH2), 3.21–3.30 (1H, m, CH2), 3.39–
3.50 (1H, m, CH2), 5.04 (1H, d, J 11.3, ¼¼CH2), 5.11 (1H, d, J
18.7, ¼¼CH2), 5.65–5.79 (1H, m, ¼¼CH), 6.10 (1H, dd, J 9.2
and 6.5, CH), 6.72 (1H, t, J 7.5, ArH), 7.07 (1H, d, J 7.6,
ArH), 7.18–7.54 (4H, m, ArH), and 8.05 (1H, d, J 8.3, ArH).
Reaction of 1-[(2-azido-5-bromo)phenylmethyl]benzotria-
zole (6d) with allyl bromide. In accordance with the afore-
mentioned general procedure, a mixture of 6d (300 mg, 0.91
mmol), allyl bromide (276 mg, 2.28 mmol), and n-BuLi
(2.28 mmol) was stirred. Chromatography of the reaction
mixture gave 2-(N,N-dibenzylamino)-3-(benzotriazol-1-yl)-5-
bromo- 2H-indazole (8i) (97 mg, 26%), 3-(benzotriazol-1-yl)-5-
bromo-2H- indazole (9i) (40 mg, 14%), [2-(benzotriazol-1-yl)
methyl-4-bromo]phenylamine (10i) (19 mg, 7%), [2-{1-(benzo-
triazol-1-yl)-3-butenyl}-4-bromo]phenylamine (11i) (12 mg,
4%), and unreacted 6d (6 mg, 2%).
8i. Viscous liquid (Found: C, 55.6; H, 4.35, N, 20.0. Calc.
for C19H17BrN6: C, 55.8; H, 4.2; N, 20.5%); mmax (film)/cmꢀ1
3064, 2936, 2856, 1632, 1603, 1582, 1558, 1516, 1444, 1384,
1278, 1196, 1092, 990, 924, 739, and 518; 1H NMR d 3.85
(4H, d, J 6.8, CH2), 4.99 (2H, d, J 10.8, ¼¼CH2), 5.04 (2H, d,
J 17.7, ¼¼CH2), 5.50–5.65 (2H, m, ¼¼CH), 7.27–7.35 (2H, m,
9j. Mp 172–174ꢁC (from CH2Cl2–n-hexane) (Found: C,
57.8; H, 3.1; N, 26.1. Calc. for C13H8ClN5: C, 57.9; H, 3.0; N,
26.0%); mmax (KBr)/cmꢀ1 3156, 3052, 2908, 2850, 1639, 1608,
1523, 1478, 1436, 1375, 1278, 1244, 1196, 1049, 984, 918,
1
852, 738, and 516; H NMR d (DMSO) 7.35 (1H, d, J ¼ 8.7,
ArH), 7.59 (1H, t, J 7.8, ArH), 7.75 (1H, d, J 7.6, ArH), 7.79
(1H, s, ArH), 8.25 (1H, d, J 5.9, ArH), 8.28 (1H, d, J 6.3,
ArH), 8.36 (1H, d, J 8.4, ArH), and 13.7 (1H, s, NH); 13C
NMR d (DMSO) 111.3, 113.7, 120.5, 123.6, 123.7, 126.2,
126.3, 130.2, 131.9, 133.8, 142.3, and 145.9
1
10j. Viscous liquid (mixed with 11j); H NMR d 4.27 (2H,
s, NH2), 5.77 (2H, s, CH2), 7.06 (1H, d, J 8.5, ArH), 7.21–7.42
(4H, m, ArH), 7.48 (1H, s, ArH), and 8.06 (1H, d, J 7.9, ArH).
1
11j. Viscous liquid (mixed with 10j); H NMR d 3.19–3.30
(1H, m, CH2), 3.35–3.49 (1H, m, CH2), 4.17 (2H, s, NH2),
5.01 (1H, d, J 10.7, ¼¼CH2), 5.06 (1H, d, J 18.9, ¼¼CH2),
5.63–5.80 (1H, m, ¼¼CH), 6.02 (1H, dd, J 9.1 and 6.6, CH),
6.64 (1H, d, J 2.0, ArH), 6.78 (1H, dd, J 8.3 and 2.0, ArH),
7.31–7.43 (4H, m, ArH), and 8.04 (1H, d, J 7.7, ArH).
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

January 2010 n-Butyllithium-Mediated Reactions of 1-(2-Azidoarylmethyl)-1H-benzotriazoles with
Alkyl Halides
109
Reaction of 1-[(2-azido-5-chloro)phenylmethyl]benzotria-
zole (6f) with allyl bromide. In accordance with the afore-
mentioned general procedure, a mixture of 6f (350 mg, 1.23
mmol), allyl bromide (377 mg, 3.08 mmol), and n-BuLi (3.08
mmol) was stirred. Chromatography of the reaction mixture
gave 2-(N,N-dibenzylamino)-3-(benzotriazol-1-yl)-5-chloro-2H-
indazole (8k) (126 mg, 28%), 3-(benzotriazol-1-yl)-5-chloro-
2H-indazole (9k) (56 mg, 17%), [2-(benzotriazol-1-yl)methyl-
4-chloro]phenylamine (10k) (6 mg, 2%), [2-{1-(benzotriazol-1-
yl)-3-butenyl}-4-chloro]phenylamine (11k) (29 mg, 8%), and
unreacted 6f (14 mg, 4%).
8k. Mp 102–104ꢁC (from CH2Cl2–n-hexane) (Found: C,
62.6; H, 4.8; N, 22.9. Calc. for C19H17ClN6: C, 62.55; H, 4.7;
N, 23.0%); mmax (KBr)/cmꢀ1 3053, 2910, 2848, 1627, 1600,
1520, 1445, 1380, 1284, 1159, 1045, 996, 924, 849, 742, and
521; 1H NMR d 3.85 (4H, d, J 6.7, CH2), 4.99 (2H, d, J ¼
12.7, ¼¼CH2), 5.04 (2H, d, J 18.0, ¼¼CH2), 5.48–5.63 (2H, m,
¼¼CH), 7.27–7.36 (3H, m, ArH), 7.46–7.61 (2H, m, ArH), 7.75
(1H, d, J 9.1, ArH), and 8.23 (1H, d, J 8.1, ArH); 13C NMR d
110.2, 116.1, 117.4, 120.5, 120.7, 120.9, 125.1, 129.0, 129.3,
130.2, 132.6, 135.2, 143.7, and 145.7.
20. Mp 128–130ꢁC (from EtOAc–n-hexane) (Found: C,
69.7; H, 5.3; N, 25.1. Calc. for C13H12N4: C, 69.6; H, 5.4; N,
25.0%); mmax (KBr)/cmꢀ1 3448, 3336, 3040, 2920, 1611, 1507,
1436, 1283, 1216, 1176, 1126, 1076, 830, 776, 736, and 518;
1H NMR d 3.76 (2H, s, NH2), 5.73 (2H, s, CH2), 6.61 (2H, d,
J 8.4, ArH), 7.13 (2H, d, J 10.1, ArH), 7.33–7.42 (3H, m,
ArH), and 8.04 (1H, d, J 8.1, ArH); 13C NMR d 52.6, 110.4,
115.6, 120.3, 124.2, 124.6, 127.6, 129.5, 133.4, 146.7, and 147.2.
Reaction of 1-(2-azidophenylmethyl)-6-chloro-1H-benzo-
triazole (6i) with allyl bromide. In accordance with the afore-
mentioned general procedure, a mixture of 6i (199 mg, 0.70
mmol), allyl bromide (212 mg, 1.75 mmol), and n-BuLi (1.75
mmol) was stirred. Chromatography of the reaction mixture
gave 2-(N,N-diallylamino)-3-(6-chlorobenzotriazol-1-yl)-2H-in-
dazole (8l) (77 mg, 30%), 3-(6-chlorobenzotriazol-1-yl)-2H-in-
dazole (9l) (23 mg, 12%), 2-[(6-chlorobenzotriazol-1-yl)methyl]-
phenylamine (10l) (11 mg, 6%), and unreacted 6i (4 mg, 2%).
8l. Viscous liquid (Found: C, 62.6; H, 4.6; N, 23.15. Calc.
for C19H17ClN6: C, 62.55; H, 4.7; N, 23.0%); mmax (film)/cmꢀ1
3056, 2906, 2865, 1631, 1608, 1518, 1473, 1444, 1374, 1280,
1166, 1043, 992, 928, 851, 744, and 522; 1H NMR d 3.87
(4H, d, J 6.3, CH2), 5.01 (2H, d, J 9.0, ¼¼CH2), 5.06 (2H, d, J
15.9, ¼¼CH2), 5.49–5.64 (2H, m, ¼¼CH), 7.22 (1H, d, J 6.7,
ArH), 7.29–7.34 (2H, m, ArH), 7.42–7.49 (2H, m, ArH), 7.82
(1H, d, J 8.9, ArH), and 8.15 (1H, d, J 8.8, ArH); 13C NMR d
60.9, 110.5, 115.7, 118.5, 118.9, 120.8, 121.7, 124.6, 126.2,
127.6, 132.7, 135.7, 144.3 and 145.4.
9k. Mp 198–200ꢁC (from CH2Cl2–n-hexane) (Found: C,
57.8; H, 2.9; N, 26.0. Calc. for C13H8ClN5: C, 57.9; H, 3.0; N,
26.0%); mmax (KBr)/cmꢀ1 3144, 3054, 2918, 2838, 1630, 1609,
1523, 1450, 1385, 1340, 1278, 1167, 1039, 994, 928, 837,
737, and 516; 1H NMR d (DMSO) 7.55 (1H, t, J 2.6, ArH),
7.58 (1H, d, J 2.2, ArH), 7.75 (2H, d, J 9.1, ArH), 8.25 (1H,
d, J 5.7, ArH), 8.26 (1H, d, J 4.3, ArH), 8.36 (1H, d, J 8.3,
ArH), and 13.8 (1H, s, NH); 13C NMR d (DMSO) 111.7,
113.5, 121.0, 123.7, 123.8, 126.5, 126.6, 130.1, 132.0, 133.9,
142.5, and 145.9.
9l. Mp 215–217ꢁC (from CH2Cl2–n-hexane) (Found: C,
57.95; H, 3.1; N, 26.0. Calc. for C13H8ClN5: C, 57.9; H, 3.0;
N, 26.0%); mmax (KBr)/cmꢀ1 3124, 3058, 2920, 2846, 1627,
1600, 1523, 1456, 1385, 1340, 1278, 1175, 1039, 994, 928, 837,
1
10k. Viscous liquid (mixed with 11k); H NMR d 4.35 (2H, s,
NH2), 5.70 (2H, s, CH2), 6.61 (1H, d, J 8.5, ArH), 7.11 (1H, d, J
8.4, ArH), 7.28–7.54 (4H, m, ArH), and 8.12 (1H, d, J 8.1, ArH).
1
737, 694, and 516; H NMR d (DMSO) 7.35 (1H, dd, J 7.7 and
6.6, ArH), 7.56 (1H, dt, J 1.0 and 6.9, ArH), 7.61 (1H, dd, J 8.9
and 1.9, ArH), 7.70 (1H, d, J 8.5, ArH), 8.24 (1H, d, J 8.3, ArH),
8.29 (1H, d, J 8.8, ArH), 8.39 (1H, d, J 1.7, ArH), and 13.6 (s, 1H,
NH); 13C NMR d (DMSO) 111.8, 113.3, 114.8, 121.7, 122.1,
123.1, 126.9, 128.9, 132.6, 134.9, 140.0, 142.1, and 144.6.
1
11k. Viscous liquid (mixed with 10k); H NMR d 3.21–3.29
(1H, m, CH2), 3.39–3.50 (1H, m, CH2), 4.05 (2H, s, NH2),
5.02 (1H, d, J 11.6, ¼¼CH2), 5.08 (1H, d, J 17.1, ¼¼CH2),
5.66–5.81 (1H, m, ¼¼CH), 6.01 (1H, dd, J 9.2 and 6.1, CH),
6.58 (1H, d, J 8.6, ArH), 7.09 (1H, d, J 8.5, ArH), 7.31–7.59
(4H, m, ArH), and 8.06 (1H, d, J 8.2, ArH).
Reaction of 1-[(2-azido-5-nitro)phenylmethyl]benzotria-
zole (6g) with allyl bromide. In accordance with the afore-
mentioned general procedure, a mixture of 6g (300 mg,
1.02 mmol), allyl bromide (308 mg, 2.55 mmol), and n-BuLi
(2.55 mmol) was stirred to give very complex mixtures, which
were unidentifiable.
Reaction of 1-(4-azidophenylmethyl)benzotriazole (6h)
with allyl bromide. In accordance with the aforementioned
general procedure, 6h (500 mg, 2.00 mmol) was treated with
n-BuLi (4.00 mmol), followed by addition of allyl bromide
(484 mg, 4.00 mmol). Chromatography of the reaction mixture
gave 1-[{(4-azidophenyl)(allyl)}methyl]-1H-benzotriazole (19)
(23 mg, 4%), 4-[(benzotriazol-1-yl)methyl]phenylamine (20)
(202 mg, 45%), and unreacted 6h (140 mg, 28%).
19. Viscous liquid (Found: C, 66.4; H, 4.8; N, 29.0. Calc.
for C16H14N4: C, 66.2; H, 4.9; N, 28.95%); mmax (film)/cmꢀ1
3056, 2920, 2848, 2112, 1683, 1595, 1500, 1443, 1276, 1224,
1155, 1064, 992, 916, 824, 744, and 529; 1H NMR d 3.17–
3.28 (1H, m, CH2), 3.46–3.58 (1H, m, CH2), 5.04 (1H, d, J
10.2, ¼¼CH2), 5.13 (d, J 18.4, ¼¼CH2), 5.65–5.77 (1H, m,
¼¼CH), 5.83 (1H, dd, J 8.8, 6.7, CH), 7.00 (2H, d, J 8.6, ArH),
7.34–7.50 (5H, m, ArH), and 8.07 (1H, d, J 7.8, ArH).
10l. Mp 87–89ꢁC (from CH2Cl2–n-hexane) (Found: C, 60.5;
H, 4.1; N, 21.6. Calc. for C13H11ClN4: C, 60.35; H, 4.3; N,
21.7%); mmax (KBr)/cmꢀ1 3348, 3231, 3042, 2950, 2856, 1601,
1
1580, 1441, 1281, 1154, 1072, 906, 742, and 521; H NMR d
4.29 (2H, s, NH2), 5.77 (2H, s, CH2), 7.10–7.19 (2H, m, ArH),
7.28 (1H, d, J 8.0, ArH), 7.31 (1H, d, J 8.7, ArH), 7.42–7.52
(2H, m, ArH), and 8.17 (1H, d, J 8.8, ArH); 13C NMR d 50.6,
110.1, 118.8, 121.4, 125.6, 125.7, 125.8, 130.4, 130.6, 133.9,
134.3, 138.4, and 145.1.
Reaction of 6a with a mixture of allyl bromide and ben-
zyl bromide. In accordance with the aforementioned general
procedure, a mixture of 6a (330 mg, 1.32 mmol), allyl bro-
mide (191 mg, 1.58 mmol), benzyl bromide (270 mg, 1.58
mmol), and n-BuLi (3.30 mmol) in THF was stirred for 1 h at
ꢀ78ꢁC to room temperature for 2 h. TLC (silica gel, EtOAc:
n-hexane ¼ 1:4) showed four major spots (Rf ¼ 0.79, 0.70,
0.42, and 0.27). The mixture was chromatographed on a silica
gel (2.5 ꢂ 13 cm2). Elution with EtOAc and n-hexane (1:6)
gave 8a (40 mg, 7%), a mixture of compounds (114 mg), 9a
(37 mg, 12 %), and 10a (29 mg, 10%). Separation of the mix-
ture has been unsuccessful. However, the 1H NMR spectrum
of the mixture indicated that the mixture consisted of 8a (39
mg, 9%) and 2-(N-allyl-N-benzylamino)-3-(benzotriazol-1-yl)-
2H-indazole (23) (75 mg, 15%). FAB MS showed mass
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

110
T. Kim and K. Kim
Vol 47
number (m/z) 331 and 381, which corresponding to the molec-
ular weights of 8a plus 1 and 23 plus 1, respectively.
135ꢁC (from CH2Cl2–n-hexane) (Found: C, 63.0; H, 5.3; N,
31.65. Calc. for C14H14N6: C, 63.1; H, 5.3; N, 31.6%); mmax
(KBr)/cmꢀ1 3263, 3066, 3003, 2954, 1431, 1371, 1220, 1077,
943, 746, 718, and 531; 1H NMR d 3.24 (3H, s, CH3), 6.16
(2H, s, CH2), 7.07–7.07 (2H, m, ArH), 7.25–7.38 (3H, m,
ArH), 7.42–7.51 (2H, m, ArH), 8.05 (1H, d, J 7.1, ArH), and
8.36 (1H, s, NH); 13C NMR d 48.4, 110.7, 120.2, 124.2,
126.7, 127.5, 129.4, 129.6, 133.4, and 146.6.
Preparation of 1-(2-aminophenylmethyl)benzotriazole
10a. In accordance with the literature procedure [7], a solution
of 1-(2-azidophenylmethyl)benzotriazole (6a) (250 mg, 1.00
mmol) in a mixture of THF (30 mL) and MeOH (0.3 mL) was
treated with NaBH4 (12 mg, 0.30 mmol). The mixture was
heated at reflux for 2 h. Work-up gave 10a (202 mg, 90%).
Reaction of 10a with allyl bromide in the presence of n-
BuLi. To a stirred solution of 10a (202 mg, 0.90 mmol) in THF
(25 mL) at ꢀ78ꢁC was added n-BuLi (2.25 mmol) and allyl bro-
mide (272 mg, 2.25 mmol). After being stirred for 2 h at room
temperature, the mixture was worked up as usual. Chromatogra-
phy (2.5 ꢂ 13 cm2) using a mixture of EtOAc and n-hexane
(1:4) as an eluent gave allyl[2-{1-(benzotriazol-1-yl)-3-butenyl}-
phenyl]amine (16) (14 mg, 5%), diallyl[2-{(benzotriazol-1-
yl)methyl}phenyl]amine (15) (89 mg, 33%), allyl[2-{(benzotria-
zol-1-yl)methyl}phenyl]amine (14) (90 mg, 38%).
23. Viscous liquid (mixed with 8a); mmax (KBr)/cmꢀ1 3056,
2924, 2840, 1628, 1600, 1554, 1523, 1444, 1370, 1226, 1160,
990, 942, 830, 740, and 520; 1H NMR d 3.97 (1H, d, J 4.6,
CH2CH¼¼CH2), 4.09 (2H, s, CH2Ph), 5.06 (1H, d, J 16.9,
¼¼CH2), 5.14 (1H, d, J 17.2, ¼¼CH2), 5.71–5.87 (1H, m,
¼¼CH), 6.77–6.97 (4H, m, ArH), 7.01–7.25 (3H, m, ArH),
7.30–7.51 (4H, m, ArH), 7.85 (1H, d, J 8.7, ArH), and 8.21
(1H, d, J 8.3, ArH); 13C NMR d 61.1, 61.6, 110.4, 118.7,
120.5, 124.2, 124.8, 127.5, 128.1, 128.6, 128.7, 128.9, 129.5,
129.6, 132.8, 134.7, 135.9, 145.4, and 145.5.
Reaction of 6a with allyl bromide in the presence of vari-
ous bases. In accordance with the aforementioned general proce-
dure, 6a (200 mg, 1.25 mmol) was treated with bases such as
tert-BuLi (1.88 mmol), NaNH2 (1.88 mmol), KN(SiMe3)2 (1.88
mmol), LDA (1.88 mmol) followed by TMEDA (145 mg, 1.25
mmol), and n-BuLi (1.88 mmol) followed by tert-BuOK (140mg,
1.25 mmol) in THF (25 mL) for 1 h at ꢀ78ꢁC and then 2 h at
room temperature. The only exception was the reaction with NaH
(1.88 mmol) for 5 h at room temperature. The reaction was
quenched by addition of water (30 mL). The mixture was
extracted with CH2Cl2 (20 mL ꢂ 3). The combined extract was
dried over MgSO4. Chromatography (2.5 ꢂ 10 cm2, EtOAc:n-
hexane ¼ 1:5) of the residue gave unreacted 6a and 8a-10a,
depending on the bases. The results are summarized in Table 3.
General procedure for the reactions of simple aryl azides
with n-BuLi. To a stirred solution of aryl azides (4.88 mmol)
in THF (25 mL) for 1 h at ꢀ78ꢁC was added n-BuLi (9.76
mmol). The mixture was stirred for 2 h at room temperature
and worked up as usual. Chromatography of the residue using
a mixture of EtOAc and n-hexane (1:10) gave alkyl aryl
amines 22, aryl amines 22, and unreacted aryl azides.
Reaction with p-azidotoluene. In accordance with the
aforementioned general procedure, p-azidotoluene (540 mg,
4.06 mmol) was treated with n-BuLi (8.12 mmol) to give p-to-
luidine (21a) (300 mg, 69%), N-butyl-p-toluidine [14] (22a)
(53 mg, 8%) and unreacted o-azidotoluene (5 mg, 1%).
Reaction with o-azidotoluene. In accordance with the
aforementioned general procedure, o-azidotoluene (650 mg,
4.88 mmol) was treated with n-BuLi (9.76 mmol) to give o-to-
luidine (21b) (397 mg, 76%), N-butyl-o-toluidine [14] (22b)
(48 mg, 6%) and unreacted o-azidotoluene (13 mg, 2%).
Reaction with o-azidoethylbenzene. In accordance with the
aforementioned general procedure, o-azidoethylbenzene (520
mg, 3.53 mmol) was treated with n-BuLi (7.06 mmol) to give
o-ethylamine (21c) (295 mg, 69%) and N-butyl-2-ethylphenyl
amine [15] (22c) (50 mg, 8%).
14. Viscous liquid (Found: C, 72.65; H, 5.9; N, 21.4. Calc.
for C16H16N4: C, 72.7; H, 6.1; N, 21.2%); mmax (film)/cmꢀ1
3260, 3054, 2928, 2865, 1603, 1480, 1446, 1316, 1228, 1156,
1
994, 742, and 526; H NMR d 3.78 (2H, s, NCH2), 4.95 (1H,
s, NH), 5.14 (1H, d, J 11.8, ¼¼CH2), 5.19 (1H, d, J 17.6,
¼¼CH2), 5.78 (2H, s, CH2), 5.83–5.98 (1H, m, ¼¼CH), 6.65
(1H, d, J 8.2, ArH), 6.76 (1H, t, J 7.4, ArH), 7.25 (1H, t, J
7.6, ArH), 7.32–7.46 (3H, m, ArH), 7.54 (1H, d, J 7.4, ArH),
and 8.05 (1H, d, J 7.6, ArH); 13C NMR d 46.4, 51.1, 110.5,
112.2, 116.6, 117.1, 118.6, 120.5, 124.4, 127.9, 130.8, 131.2,
133.2, 135.0, 146.7, and 147.4.
15. Viscous liquid (Found: C, 75.2; H, 6.5; N, 18.25. Calc.
for C19H20N4: C, 75.0; H, 6.6; N, 18.4%); mmax (film)/cmꢀ1
3056, 3001, 2948, 2920, 1608, 1511, 1490, 1442, 1248, 1110,
996, 910, 740, 694, and 516; 1H NMR d 3.65 (4H, d, J 6.3,
NCH2), 5.17 (2H, d, J 11.5, ¼¼CH2), 5.23 (2H, d, J 17.2,
¼¼CH2), 5.83–5.92 (2H, m, CH), 6.02 (2H, s, CH2), 6.87 (1H,
d, J 8.2, ArH), 7.01 (1H, t, J 7.4, ArH), 7.22–7.43 (6H, m,
ArH), and 8.08 (1H, d, J 8.2, ArH).
16. Viscous liquid (Found: C, 74.9; H, 6.5; N, 18.6. Calc.
for C19H20N4: C, 75.0; H, 6.6; N, 18.4%); mmax (film)/cmꢀ1
3271, 3048, 2920, 1624, 1489, 1445, 1300, 1256, 1221, 1154,
996, 740, and 521; 1H NMR
d 3.25–3.34 (1H, m,
CHCH2CH¼¼CH2), 3.45–3.56 (1H, m, CHCH2CH¼¼CH2), 3.69
(2H, s, NHCH2CH¼¼CH2), 4.54 (1H, s, NH), 4.98–5.14 (4H,
m, CHCH2CH¼¼CH2 and NHCH2CH¼¼CH2), 5.68–5.89 (2H,
m, CHCH2CH¼¼CH2 and NHCH2CH¼¼CH2), 6.14 (1H, dd, J
9.4 and 6.2, CH), 6.63 (1H, d, J 8.2, ArH), 6.82 (1H, t, J 7.5,
ArH), 7.23 (1H, t, J 8.4, ArH), 7.28–7.36 (2H, m, ArH), 7.42–
7.46 (1H, m, ArH), 7.52 (1H, d, J 7.7, ArH), and 8.04 (1H, d,
J 7.2, ArH); 13C NMR d 36.5, 46.4, 60.8, 110.9, 112.5, 116.5,
117.3, 119.1, 120.5, 121.1, 124.4, 127.7, 127.9, 130.3, 132.5,
133.7, 134.9, 146.8, and 147.1.
Reaction with 2-azidodiphenylmethane. In accordance
with the aforementioned general procedure, 2-azidodiphenyl-
methane (500 mg, 2.39 mmol) was treated with n-BuLi (4.78
mmol) to give o-(n-butylamino)diphenylmethane [16] (22d)
(40 mg, 7%) and 2-benzylaniline [17] (21d) (315 mg, 72%).
Reaction of 6a with methylmagnesium bromide. To a so-
lution of methylmagnesium bromide (250 mg, 2.10 mmol) in
THF (15 mL) at 0ꢁC was added 6a (350 mg, 1.40 mmol). The
mixture was stirred for 1 h at 0ꢁC and then at room tempera-
ture for 2 h. The mixture was worked up as usual and chroma-
tographed on a silica gel (2.5 ꢂ 5 cm2) using a mixture of
EtOAc and n-hexane (1:1) to give 2-[(benzotriazol-1-yl)me-
thyl]phenyl methyltriazene (13) (338 mg, 91%). Mp 133–
Acknowledgments. This work was supported by the S. N. U.
foundation of Overhead Research Fund and Kolon Life Science,
Inc.
Journal of Heterocyclic Chemistry
DOI 10.1002/jhet

January 2010 n-Butyllithium-Mediated Reactions of 1-(2-Azidoarylmethyl)-1H-benzotriazoles with
Alkyl Halides
111
699, 17; (e) Lee, K. Y.; Gowrisankar, S.; Kim, J. N. Tetrahedron Lett
2005, 46, 5387; (f) Rosati, O.; Curini, M.; Marcotullio, M. C.; Mac-
chiarulo, A.; Perfumi, M.; Mattioli, L.; Rismondo, F.; Cravotto, G.
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Journal of Heterocyclic Chemistry
DOI 10.1002/jhet