A novel method for the synthesis of 2,3-benzo-1,3a,6a-triazapentalenes through Pummerer-type reactions of γ-(benzotriazol-1-yl)allylic sulfoxides

Article abstract of DOI:10.1002/1099-0690(20022)2002:3<493::AID-EJOC493>3.0.CO;2-B

Treatment of 1-(arylmethyl)benzotriazoles 1 with nBuLi in THF at -78 °C, followed by addition of 1-aryl-2-chloroethanones, gave diastereomeric mixtures of 1-[(aryl)(benzotriazol-1-yl) methyl]oxiranes 2. Treatment of 2 with nBuLi in THF at -78 °C, followed by acidification, afforded a mixture of (E)- and (Z)-allylic alcohols 3, which were converted into 1,2-disubstituted 2-(alkyl- or aryl)-1-(benzotriazol-1-yl)-3-sulfanylpropenes 5 via the corresponding allylic chlorides 4. Oxidation of sulfides 5 by mCPBA in CH₂Cl₂ at room temperature, followed by treatment with trifluoroacetic anhydride (TFAA) at room temperature, gave the title compounds in good yields. It was found that treatment of the title compounds with Raney-Ni in EtOH under hydrogen at reflux gave 2-(pyrazol-1-yl)aniline derivatives in excellent yields.

Full text of DOI:10.1002/1099-0690(20022)2002:3<493::AID-EJOC493>3.0.CO;2-B

FULL PAPER
A Novel Method for the Synthesis of 2,3-Benzo-1,3a,6a-triazapentalenes
through Pummerer-Type Reactions of γ-(Benzotriazol-1-yl)allylic Sulfoxides
Taehoon Kim,[a] Kyongtae Kim,*[a] and Yung Ja Park*[b]
Keywords: Betaines / Electrophilic additions / Epoxidations / Heterocycles
Treatment of 1-(arylmethyl)benzotriazoles 1 with nBuLi in
sulfanylpropenes 5 via the corresponding allylic chlorides 4.
THF at −78 °C, followed by addition of 1-aryl-2-chloroe- Oxidation of sulfides 5 by mCPBA in CH2Cl2 at room temper-
thanones, gave diastereomeric mixtures of 1-[(aryl)(benzotri-
azol-1-yl)methyl]oxiranes 2. Treatment of 2 with nBuLi in
THF at −78 °C, followed by acidification, afforded a mixture
of (E)- and (Z)-allylic alcohols 3, which were converted into
1,2-disubstituted 2-(alkyl- or aryl)-1-(benzotriazol-1-yl)-3-
ature, followed by treatment with trifluoroacetic anhydride
(TFAA) at room temperature, gave the title compounds in
good yields. It was found that treatment of the title com-
pounds with Raney-Ni in EtOH under hydrogen at reflux
gave 2-(pyrazol-1-yl)aniline derivatives in excellent yields.
Introduction
moiety takes place at the γ-position of an allyl sulfoxide,
followed by application of Pummerer-type conditions.
Heteropentalenes belonging to class B in Ramsden’s clas-
sification[1] have received considerable attention from the
point of view of their electronic structure and potential syn-
thetic utility.[2] This class of mesomeric betaines has basic-
ally been synthesized by two different methods. The first
method, which has been most widely used, involves treat-
ment of 1-(o-nitroaryl)pyrazoles[3] or 1-(o-nitroaryl)inda-
zoles[4] with triethyl phosphite. Similarly, treatment of 2-
benzoyl-2Ј-nitroazobenzene with triethylphosphite gave tri-
azapentalenes.[5] The second method involves photolysis of
1-(o-azidoaryl)indazoles and pyrazoles.[4a,6] Thermally or
photochemically generated free nitrenes or nitrenoid-like
species may be involved as intermediates. In addition, al-
kylation of pyrazoles, followed by cyclodehydration with
aqueous alkali,[7] and N-amination of 1-phenacylpyrazole
with o-mesitylenesulfonylhydroxylamine[8] have been re-
ported to give triazapentalenes.
In connection with our ongoing project exploring the po-
tential utility of benzotriazole as a synthetic auxiliary,[9]
thionium ions generated from benzotriazoles bearing
tethered sulfoxides under Pummerer conditions were inten-
ded to be utilized as electrophiles, affording triazapental-
enes. This should occur if internal trapping of the Pumm-
erer thionium ion by the N-2 atom of the benzotriazole
Results and Discussion
We prepared a diastereomeric mixture of [(aryl)(benzotri-
azol-1-yl)methyl]oxiranes 2 by treatment of 1-(arylmethyl)-
benzotriazoles 1 with nBuLi in THF at Ϫ78 °C, followed
by addition of 1-aryl-2-chloroethanones, and assigned the
configurations of the stereocenters according to a reported
procedure[9] (Scheme 1). Upon treatment of 2 with nBuLi
(1.5 equiv.) in THF at Ϫ78 °C, followed by acidification, a
mixture of (E)- and (Z)-allylic alcohols 3 was obtained. The
mixture was separated by column chromatography. The ste-
reochemistry of (E)- and (Z)-3 was determined by NOE
investigations. For example, compound (E)-3g (Ar ϭ 4-
FC6H4, R1 ϭ 2,5-Me2C6H3), with a singlet at δ ϭ 4.63
(600 MHz, CDCl3) assignable to the allylic protons, dis-
played NOE effects between two ortho protons (δ ϭ
7.45Ϫ7.47) of the 4-FC6H4 group and one ortho proton
(δ ϭ 6.93) of the 2,5-Me2C6H3 group, whereas compound
(Z)-3g had NOE effects arising from the allylic protons
(δ ϭ 4.19) and a single ortho proton (δ ϭ 7.11) of the 2,5-
Me2C6H3 group. Similar NOE effects were observed for the
other allylic alcohols (E)- and (Z)-3. Consequently, one can
readily determine the ratio of (E)- and (Z)-3 from the chem-
ical shifts of the allylic protons of 3, without separation of
the stereoisomers. The allylic alcohols were converted into
allylic chlorides 4 with SOCl2 (3 equiv.) in THF at room
temperature.
[a]
School of Chemistry and Molecular Engineering, Seoul
National University,
Seoul 151-742, Korea
Fax: (internat.) ϩ 82-2/874-8858
E-mail: kkim@plaza.snu.ac.kr
Unexpectedly, the conversion of 3 into 4 was accompan-
ied by isomerization, and so their ratio in a mixture of (E)-
and (Z)-4 would be different from that in a mixture of the
[b]
Department of Chemistry, Sook Myung Women’s University,
Seoul 140-742, Korea
Eur. J. Org. Chem. 2002, 493Ϫ502
WILEY-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002
1434Ϫ193X/02/0203Ϫ0493 $ 17.50ϩ.50/0
493

T. Kim, K. Kim, Y. J. Park
FULL PAPER
mers showed absorptions downfield from those of (Z) iso-
mers. Yields of compounds 2؊6 and the ratios of the ste-
reoisomers of each compound are summarized in Table 1.
Treatment of compounds 6, irrespective of their stereo-
chemistry, with trifluoroacetic anhydride (TFAA) (5 equiv.)
in THF for 1 h at room temperature gave triazapentalenes
7 in good yields (Table 2).
Table 2. Yields of triazapentalenes 7
Product Ar
R1
R2
Yield [%][a]
7a
7b
7c
7d
7e
7f
7g
7h
7i
Ph
Ph
Ph
Ph
Ph
4-MeC6H4
tBu
Ph
Ph
Ph
Ph
Ph
85
79
88
CH2CH2OH 34
Ph
Ph
4-FC6H4
4-FC6H4
4-FC6H4
4-FC6H4
4-FC6H4
4-MeOC6H4 Ph
4-MeOC6H4 4-MeC6H4
82
79
82
Me
2,5-Me2C6H3 Ph
2,5-Me2C6H3 4-MeOC6H4 76
Me
Scheme 1. Synthesis of 2,3-benzo-1,3a,6a-triazapentalenes 7: a)
ref.[9]; b) nBuLi, THF, Ϫ78 °C, 0.5 h; c) SOCl2, THF, 25 °C, 1 h;
d) R2SH, NaOEt, THF, 25 °C, 5 h; e) m-CPBA, CH2Cl2, 25 °C,
10 min; f) TFAA, THF, 25 °C, 1 h
nPr
Ph
Ph
85
91
80
7j
7k
[a]
corresponding stereoisomer 3. The chlorides 4 were con-
verted into sulfides 5 by treatment with thiols (5 equiv.) in
the presence of NaOEt in THF at room temperature. The
Isolated yields.
The structures of compounds 7 were determined from
stereochemistry of 4 was retained during the formation of spectroscopic and analytical data. In particular, the 1H and
5. The mCPBA-mediated (1 equiv.) oxidation of a mixture 13C NMR spectroscopic data were informative regarding
of (E)- and (Z)-5 gave a mixture of (E)- and (Z)-sulfoxides the structures of 7, since compounds 7a, 7e, and 7j do not
6, which were separable by chromatography. The stereo- exhibit any 1H NMR absorptions corresponding to ali-
chemistry was judged with the aid of the H NMR spectra phatic protons or 13C NMR absorptions at fields above δ ϭ
1
of compounds 6 prepared from pure (E)-5 and from pure 100, indicating the absence of even a quaternary carbon
(Z)-5 to be retained during these oxidations. The ratios of atom.[10] These spectroscopic properties, coupled with the
the stereoisomers of compounds 2؊6 were determined on X-ray single-crystal structure of 7f, clearly indicate that
the basis of the allylic proton absorptions, in which (E) iso- compounds 7 have planar triazapentalene skeletons (Fig-
Table 1. Yields of products 2Ϫ6 and ratios of the stereoisomers
Product Ar
R1
R2
Yield (%)[a]
2
3
4
5
6
(R,R)/(S,S); (R,S)/(S,R) (E)/(Z)
(E)/(Z)
(E)/(Z)
(E)/(Z)
a
b
c
d
e
f
g
h
i
Ph
Ph
Ph
Ph
Ph
4-MeC6H4
tBu
Ph
Ph
Ph
Ph
Ph
50 (2.22:1)
28 (1.48:1)
23[b]
87 (1.84:1) 86 (3.11:1)
80 (1.31:1) 83 (2.51:1)
71 (2.98:1)
67 (2.46:1)
70 (1.54:1)
86[d]
88 (3.05:1)
85 (2.38:1)
86 (1.48:1)
90[e]
92 (5.42:1)
91 (6.94:1)
62 (2.71:1)
75[c]
87 (1.57:1)
87 (1.84:1) 86 (3.11:1)
CH2CH2OH 50 (2.22:1)
Ph
Ph
4-FC6H4
4-FC6H4
4-FC6H4
4-FC6H4
4-FC6H4
4-MeOC6H4 Ph
4-MeOC6H4 4-MeC6H4
37 (1.22:1)
55 (1.17:1)
42 (1.09:1)
84 (1.19:1) 87 (4.84:1)[f] 83 (5.54:1)
Me
75 (1.41:1) 78 (7.05:1)
85 (1.18:1) 91 (2.78:1)[g] 82 (2.81:1)
85 (1.18:1) 91 (2.78:1)
81 (7.00:1)
2,5-Me2C6H3 Ph
2,5-Me2C6H3 4-MeOC6H4 42 (1.09:1)
Me
69 (1.12:1)[h] 86 (1.02:1)
nPr
Ph
Ph
55 (1.17:1)
50 (1.31:1)
61 (1.48:1)
75 (1.41:1) 79 (5.19:1)[i] 64 (5.41:1)
89[j]
94 (1:1.85)
93 (1:2.02)
j
k
83[k]
90[l]
84 (1:1.88)
84 (1:2.04)
89 (1:1.91)
69 (1:2.06)
[a]
Isolated yields. The ratios of the stereoisomers were determined from the 1H NMR (300 MHz, CDCl3) spectroscopic data. Each
[b]
compound was prepared from the precursor, the ratio of stereoisomers of which was specified otherwise stated.
(R,S)-2c: negligible on the basis of the H NMR spectrum. Yield of (E)-3c.
4d. Yield of (E)-6d obtained from treatment of pure (E)-5d. The (E)/(Z) ratio was obtained from treatment of 3e [(E)/(Z) ϭ 0.96:1],
Yield of (R,R)-2c.
Yield of (E)-5d obtained from treatment of pure (E)-
1
[c]
[d]
[e]
[f]
[g]
recovered from the repeated chromatography of 3e [(E)/(Z) ϭ 1.19:1] for the separation of the stereoisomers.
obtained from treatment of pure (E)-3g.
The (E)/(Z) ratio was
[h]
The (E)/(Z) ratio was obtained from treatment of 4h [(E)/(Z) ϭ 1.14:1], recovered from the
[i]
repeated chromatography of 4h [(E)/(Z) ϭ 2.78:1]. The (E)/(Z) ratio was obtained from treatment of 3i [(E)/(Z) ϭ 0.84:1], recovered
[j]
[k]
from the repeated chromatography of 3i [(E)/(Z) ϭ 1.41:1]. Yield of (E)-6i obtained from treatment of pure (E)-5i.
Yield of (Z)-3j
[l]
obtained from treatment of pure (R,S)-2j. Yield of (Z)-3k obtained from treatment of pure (R,S)-2k.
494
Eur. J. Org. Chem. 2002, 493Ϫ502

Synthesis of 2,3-Benzo-1,3a,6a-triazapentalenes
FULL PAPER
ure 1). The X-ray crystal structure of 7f[11] shows that the
N1ϪN2 and N2ϪN3 bond lengths are 1.3775(58) and
˚
1.3417(59) A, respectively, values which are close to each
other. In addition, the C7ϪC8 and C8ϪC10 bond lengths
˚
are 1.3801(71) and 1.3993(77) A, respectively, indicating the
absence of a localized double bond.
Scheme 2. Reaction of 6d with TFAA
of a more stable conjugated thionium ion 10 rather than a
nonconjugated ion 11.
Figure 1. ORTEP drawing of the molecular structure of 7f; the
thermal ellipsoids are set at the 50% probability level; the hydrogen
˚
atoms are omitted for clarity; selected bond lengths [A] and angles
[°]: N1ϪC7 1.3807(65), C7ϪC8 1.3801(71), C8ϪC10 1.3993(77),
N2ϪC10 1.3673(69), N1ϪN2 1.3775(58), N2ϪN3 1.3417(59);
C12ϪN1ϪN2
N2ϪN3ϪC11
N1ϪN2ϪC10
C7ϪC8ϪC10
105.85(0.39),
103.46(0.39),
108.22(0.44),
108.23(0.46),
N1ϪN2ϪN3
C7ϪN1ϪN2
N1ϪC7ϪC8
C8ϪC10ϪN2
113.64(0.39),
108.88(0.39),
107.08(0.43),
107.57(0.47),
C9ϪC8ϪC10 124.20(0.53), N2ϪC10ϪS 119.60(0.45), C8ϪC10ϪS
132.83(0.42), C1ϪC7ϪC8 131.23(0.47), C7ϪC8ϪC9 127.43(0.52)
Apart from the cases of compounds 6 bearing an alkyl-
or arylthio group, treatment of (E)-6d (Ar ϭ R1 ϭ Ph, R2 ϭ
CH2CH2OH) with TFAA under the same conditions gave
a mixture exhibiting two spots (Rf ϭ 0.58, 0.47; EtOAc/n-
hexane, 1:5) on TLC. However, the spot with the higher Rf
value slowly faded out concomitantly with the appearance
of a new spot (Rf ϭ 0.18). Chromatography (silica gel,
70Ϫ230 mesh; EtOAc/n-hexane, 1:5) of the reaction mixture
gave three compounds. The first was a small amount of an
unknown compound (Rf ϭ 0.58), subsequently identified as
trifluoroacetate 8 (8%) (Scheme 2), showing an IR (neat)
band at 1777 cmϪ1 (CϭO) and 13C NMR (75 MHz,
CDCl3) absorptions at δ ϭ 157.4 (CϭO, JCϪCF3 ϭ 42.1 Hz,
Interestingly, treatment of sulfoxide 12 [(E)/(Z) ϭ 2.78:1]
(Scheme 3), prepared in three steps from 4a and 1-methyl-
2-mercaptoimidazole, under the same conditions gave alde-
hyde 13 [(E)/(Z) ϭ 1.56:1] in 70% yield. The formation of
13 may be explained by hydrolysis of the thionium interme-
quadruplet), and a quadruplet at δ ϭ 114.6 (CF3, JCϪF
ϭ
282.4 Hz). The 19F NMR spectrum (470 MHz, CDCl3)
showed an absorption at δ ϭ Ϫ75.4. Compound 7d (Rf ϭ
0.18) and (E)-9 (Rf ϭ 0.47) were also isolated, in 34 and
40% yields, respectively. Treatment of 7d with TFAA in
THF at reflux gave compound 8. Compound 9 is believed
to be competitively formed by an alternative intramolecular
trapping of a hydroxy group by 2-hydroxyethylthionium
ion.
Treatment of 6i (Ar ϭ 4-FC6H4, R1 ϭ Me, R2 ϭ nPr)
under the same conditions gave only a single mesomeric
betaine 7i (85%). This result indicates that the loss of a pro-
ton to give a thionium ion occurs regioselectively in favor Scheme 3. Synthesis of β-(benzotriazol-1-yl)allylic aldehyde 13
Eur. J. Org. Chem. 2002, 493Ϫ502
495

T. Kim, K. Kim, Y. J. Park
FULL PAPER
EtOAc/n-hexane solvent mixtures. Melting points were measured
with a Fisher-Johns melting point apparatus and are uncorrected.
Elemental analyses were carried out by the Korea Basic Science
Institute. For the synthesis of the 1-(alkyl or aryl)-1-[(aryl)(benzo-
triazol-1-yl)methyl]oxiranes 2, see ref.[9]
diate 14, which rapidly undergoes hydrolysis rather than in-
tramolecular cyclization, yielding 13 when the hetarylthio
group acts as a good stable leaving group.
In order to remove the alkyl- or arylthio groups from 7,
selected compounds 7a, 7c, 7i, and 7k were treated with
Raney-Ni in EtOH under hydrogen at reflux[12] (Scheme 4).
However, reductive ring-cleavage occurred to give the cor-
responding 2-(4,5-disubstituted pyrazol-1-yl)anilines 15a,
15c, 15i, and 15k in excellent yields.
General Procedure for the Synthesis of 3: nBuLi (0.39Ϫ0.92 mmol)
was added at Ϫ78 °C to a solution of 2 (0.26Ϫ0.61 mmol) in THF
(30 mL). The mixture was stirred for 30 min, followed by addition
of 0.1  HCl (50 mL), and extracted with CH2Cl2 (30 mL ϫ 3).
The extracts were dried with MgSO4. Removal of the solvent in
vacuo gave a residue, which was chromatographed on a silica gel
column (3 ϫ 10 cm; EtOAc/n-hexane, 1:1) to give compound 3.
(E)-3-(Benzotriazol-1-yl)-2,3-diphenyl-2-propenol {(E)-3a [or (E)-
3d]}: M.p. 148Ϫ150 °C (MeOH). IR (KBr): ν˜ ϭ 3340, 3048, 2920,
1478, 1440, 1232, 1073, 1020, 761, 740, 705 cmϪ1 1H NMR
.
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.10 (br. s, 1 H, CH2OH),
4.76 (d, J ϭ 6.1 Hz, 2 H, CH2OH), 7.05Ϫ7.12 (m, 6 H, ArH),
7.20Ϫ7.31 (m, 2 H, ArH), 7.35Ϫ7.43 (m, 5 H, ArH), 7.90 (d, J ϭ
7.6 Hz, 1 H, ArH). 13C NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ
64.1, 110.7, 120.2, 124.2, 128.1, 128.3, 128.6, 129.0, 129.2, 129.3,
130.0, 133.7, 134.7, 135.7, 137.2, 140.5, 145.7. C21H17N3O (327.38):
calcd. C 77.04, H 5.23, N 12.84; found C 77.10, H 5.13, N 12.91.
Scheme 4. Synthesis of 2-(pyrazol-1-yl)aniline derivatives 16
Compounds 15a, 15c, 15i, and 15k were viscous liquids
and were converted into the corresponding acetamido de-
rivatives 16 for analysis. Yields of 15 and 16, together with
reaction times yielding 15, are summarized in Table 3.
(Z)-3-(Benzotriazol-1-yl)-2,3-diphenyl-2-propenol {(Z)-3a [or (Z)-
˜
3d]}: M.p. 151Ϫ153 °C (MeOH). IR (KBr): ν ϭ 3312, 3048, 2896,
Table 3. Yields of products 15 and 16
1480, 1441, 1265, 1097, 1076, 740, 694 cmϪ1 1H NMR (CDCl3,
.
Starting
compound
7
Ar
R1
R2 Time [h] Products
yield [%][a]
300 MHz, 25 °C, TMS): δ ϭ 2.89 (br. s, 1 H, CH2OH), 4.26 (d,
J ϭ 7.2 Hz, 2 H, CH2OH), 6.88Ϫ6.93 (m, 3 H, ArH), 7.11Ϫ7.40
(m, 10 H, ArH), 8.12 (d, J ϭ 7.9 Hz, 1 H, ArH). 13C NMR (CDCl3,
75 MHz, 25 °C, TMS): δ ϭ 64.3, 111.7, 120.6, 124.9, 128.4, 128.6,
128.8, 129.0, 129.2, 129.3, 130.1, 133.5, 134.6, 135.0, 138.5, 140.8,
146.3. C21H17N3O (327.38): calcd. C 77.04, H 5.23, N 12.84; found
C 77.08, H 5.10, N 12.88.
15
16
a
c
i
Ph
Ph
Ph
tBu
Me
Ph 15[b]
89
86
89
92
94
91
95
92
Ph
3
5
3
4-FC6H4
4-MeOC6H4 4-MeC6H4 Ph
nPr
k
3-(Benzotriazol-1-yl)-3-phenyl-2-(4-tolyl)-2-propenol (3b): Viscous
Solvent: THF.
˜
liquid; (E)/(Z) (CDCl3) ϭ 1.31:1. IR (neat): ν ϭ 3360, 3040, 2912,
1601, 1483, 1441, 1377, 1267, 1232, 1152, 1062, 1022, 816, 742, 699
cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.19 (s, 3
.
Conclusions
H, CH3, E), 2.33 (s, 3 H, CH3, Z), 2.34 (s, 1 H, CH2OH, E), 2.86
(t, J ϭ 7.1 Hz, 1 H, CH2OH, Z), 4.25 (d, J ϭ 7.1 Hz, 2 H, CH2OH,
Z), 4.78 (s, 2 H, CH2OH, E), 6.81Ϫ7.50 (m, 12 H, ArH, E and
Z), 7.95 (d, J ϭ 7.2 Hz, 1 H, ArH, E), 8.13 (d, J ϭ 7.9 Hz, 1 H,
ArH, Z).
A novel method has been developed for the synthesis of
triazapentalene derivatives by treatment of γ-(benzotriazol-
1-yl)allylic sulfoxides with trifluoroacetic anhydride in THF
at room temperature Mesomeric betaines bearing alkyl- or
arylthio groups have been found to be good precursors for
2-(4,5-disubstituted pyrazol-1-yl)anilines, which were previ-
ously difficult to obtain.
3-(Benzotriazol-1-yl)-2-(tert-butyl)-3-phenyl-2-propenol
[(E)-3c]:
M.p. 153Ϫ155 °C (MeOH). IR (KBr): ν ϭ 3312, 3048, 2950, 1595,
1480, 1435, 1363, 1265, 1230, 1080, 741, 691 cmϪ1 1H NMR
˜
.
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 1.03 [s, 9 H, C(CH3)3], 2.31
(s, 1 H, CH2OH), 4.37 (s, 2 H, CH2OH), 7.19Ϫ7.42 (m, 8 H, ArH),
8.03 (d, J ϭ 7.6 Hz, 1 H, ArH). 13C NMR (CDCl3, 75 MHz, 25
°C, TMS): δ ϭ 30.5, 37.5, 62.2, 111.1, 120.1, 124.4, 128.3, 128.9,
129.2, 129.3, 134.4, 135.2, 137.8, 146.1, 150.0. C19H21N3O (307.39):
calcd. C 74.24, H 6.89, N 13.67; found C 74.31, H 6.91, N 13.59.
Experimental Section
1
General: The H and 13C NMR spectra were recorded at 300 and
75 MHz, respectively, in CDCl3 solution containing Me4Si as an
internal standard, with a Bruker-Spectrospin spectrometer. Com-
plete assignment was achieved by NOE and 2D NMR correlation
experiments. The 19F NMR spectra were recorded at 470 MHz in
CDCl3 solution containing CFCl3 as an external standard. IR spec-
tra were obtained in KBr or as thin films on KBr plates with a
Shimadzu IR-470 infrared spectrophotometer. All reactions were
monitored for completion by thin layer chromatography (TLC),
3-(Benzotriazol-1-yl)-3-(4-fluorophenyl)-2-phenyl-2-propenol
(3e):
˜
Viscous liquid; (E)/(Z) (CDCl3) ϭ 1.19:1. IR (neat): ν ϭ 3360,
3048, 2920, 1600, 1511, 1448, 1370, 1265, 1231, 1079, 746, 694
cmϪ1. 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.77 (t, J ϭ
5.7 Hz, 1 H, CH2OH, E), 2.96 (t, J ϭ 7.0 Hz, 1 H, CH2OH, Z),
4.23 (d, J ϭ 6.9 Hz, 2 H, CH2OH, Z), 4.73 (d, J ϭ 5.4 Hz, 2 H,
CH2OH, E), 6.73Ϫ7.51 (m, 12 H, ArH, E and Z), 7.89 (d, J ϭ
8.0 Hz, 1 H, ArH, E), 8.05Ϫ8.14 (m, 1 H, ArH, Z).
which was performed on precoated silica gel plates (Merck 60 F254
)
and detection was achieved with the aid of UV light. Column chro-
3-(Benzotriazol-1-yl)-3-(4-fluorophenyl)-2-methyl-2-propenol [3f (or
˜
matography was performed on silica gel (70Ϫ230 mesh) with
3i)]: Viscous liquid; (E)/(Z) (CDCl3) ϭ 1.41:1. IR (neat): ν ϭ 3368,
496
Eur. J. Org. Chem. 2002, 493Ϫ502

Synthesis of 2,3-Benzo-1,3a,6a-triazapentalenes
FULL PAPER
3042, 2912, 1595, 1505, 1441, 1371, 1267, 1227, 1156, 1089, 1008, 126.3, 128.6, 128.7, 128.9, 129.0, 129.1, 129.4, 129.8, 130.0, 135.3,
904, 745, 520 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): 137.7, 138.2, 146.2. C21H16ClN3 (345.82): calcd. C 72.93, H 4.66,
.
δ ϭ 1.82 (s, 3 H, CH3, E), 2.21 (s, 3 H, CH3, Z), 3.07 (s, 1 H, N 12.15; found C 72.87, H 4.77, N 12.13.
CH2OH, E), 3.10 (s, 1 H, CH2OH, Z), 3.93 (s, 2 H, CH2OH, Z),
1-[3-Chloro-1-phenyl-2-(4-tolyl)propenyl]-1H-benzotriazole
(4b):
4.46 (s, 2 H, CH2OH, E), 6.88Ϫ7.45 (m, 7 H, ArH, E and Z),
8.04Ϫ8.12 (m, 1 H, ArH, E and Z).
˜
Viscous liquid; (E)/(Z) (CDCl3) ϭ 2.51:1. IR (neat): ν ϭ 3040,
2920, 1479, 1440, 1375, 1252, 1040, 756, 696 cmϪ1 1H NMR
.
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.20 (s, 3 H, CH3, E), 2.36
(s, 3 H, CH3, Z), 4.32 (s, 2 H, CH2Cl, Z), 4.72 (s, 2 H, CH2Cl, E),
6.77Ϫ7.60 (m, 12 H, ArH, E and Z), 7.97 (d, J ϭ 7.1 Hz, 1 H,
ArH, E), 8.13 Ϫ8.21 (m, 1 H, ArH, Z).
3-(Benzotriazol-1-yl)-2-(2,5-dimethylphenyl)-3-(4-fluorophenyl)-2-
propenol [3g (or 3h)]: Viscous liquid; (E)/(Z) (CDCl3) ϭ 1.18:1. IR
˜
(neat): ν ϭ 3360, 3040, 2920, 1593, 1497, 1443, 1374, 1265, 1225,
1155, 841, 740, 526 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C,
.
TMS): δ ϭ 2.12 (s, 3 H, CH3, E), 2.20 (s, 3 H, CH3, Z), 2.22 (s, 3
H, CH3, E), 2.33 (t, J ϭ 5.8 Hz, 1 H, CH2OH, E), 2.34 (s, 3 H,
CH3, Z), 2.87 (t, J ϭ 7.2 Hz, 1 H, CH2OH, Z), 4.09Ϫ4.24 (m, 2
H, CH2OH, Z), 4.48Ϫ4.68 (m, 2 H, CH2OH, E), 6.72Ϫ7.53 (m, 10
H, ArH, E and Z), 7.86 (d, J ϭ 8.2 Hz, 1 H, ArH, E), 8.12Ϫ8.19
(m, 1 H, ArH, Z).
1-(2-Chloromethyl-3,3-dimethyl-1-phenylbut-1-enyl)-1H-benzo-
triazole (4c): Viscous liquid; (E)/(Z) (CDCl3) ϭ 1.57:1. IR (neat):
1
ν˜ ϭ 3048, 2928, 1477, 1438, 1377, 1238, 1038, 760, 691 cmϪ1. H
NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 1.09 [s, 9 H, C(CH3)3,
E], 1.28 [s, 9 H, C(CH3)3, Z], 4.04 (s, 2 H, CH2Cl, Z), 4.28 (s, 2 H,
CH2Cl, E), 7.26Ϫ7.55 (m, 8 H, ArH, E and Z), 8.01Ϫ8.10 (m, 1
H, ArH, E and Z).
3-(Benzotriazol-1-yl)-3-(4-methoxyphenyl)-2-phenyl-2-propenol (3j):
˜
Viscous liquid; (E)/(Z) (CDCl3) ϭ 1.19:1. IR (neat): ν ϭ 3362,
1-[3-Chloro-1-(4-fluorophenyl)-2-phenylpropenyl]-1H-benzotriazole
(4e): Viscous liquid; (E)/(Z) (CDCl3) ϭ 4.84:1. IR (neat): ν˜ ϭ 3048,
2912, 1488, 1436, 1377, 1240, 1052, 742, 699, 521 cmϪ1. E/Z
(CDCl3) ϭ 4.84:1. 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
4.33 (s, 2 H, CH2Cl, Z), 4.69 (s, 2 H, CH2Cl, E), 6.73Ϫ7.54 (m, 12
H, ArH, E and Z), 7.95 (d, J ϭ 8.1 Hz, 1 H, ArH, E), 8.12Ϫ8.19
(m, 1 H, ArH, Z).
3024, 2912, 1601, 1503, 1444, 1370, 1230, 1065, 756, 526 cmϪ1. 1H
NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.62 (s, 1 H, CH2OH,
E), 3.01 (s, 1 H, CH2OH, Z), 3.72 (s, 3 H, OCH3, Z), 3.80 (s, 3 H,
OCH3, E), 4.22 (s, 2 H, CH2OH, Z), 4.75 (s, 2 H, CH2OH, E),
6.54Ϫ7.47 (m, 12 H, ArH, E and Z), 7.89 (d, J ϭ 7.6 Hz, 1 H,
ArH, E), 8.12 (d, J ϭ 7.92, 1 H, ArH, Z).
(Z)-3-(Benzotriazol-1-yl)-3-(4-methoxyphenyl)-2-(4-tolyl)-2-
1-[3-Chloro-1-(4-fluorophenyl)-2-methylpropenyl]-1H-benzotriazole
˜
propenol [(Z)-3k]: M.p. 156Ϫ158 °C (MeOH). IR (KBr): ν ϭ 3368,
˜
4f (or 4i): Viscous liquid; (E)/(Z) (CDCl3) ϭ 7.05:1. IR (neat): ν ϭ
3042, 2920, 1595, 1499, 1441, 1374, 1236, 1081, 748, 520 cmϪ1. 1H
NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.33 (s, 3 H, CH3),
2.86 (t, J ϭ 6.96 Hz, 1 H, CH2OH), 3.71 (s, 3 H, OCH3), 4.20 (d,
J ϭ 6.8 Hz, 2 H, CH2OH), 6.63 (d, J ϭ 7.8 Hz, 2 H, ArH), 6.84
(d, J ϭ 7.2 Hz, 2 H, ArH), 6.94 (d, J ϭ 7.1 Hz, 1 H, ArH), 7.11
(d, J ϭ 8.0 Hz, 2 H, ArH), 7.24 (d, J ϭ 8.1 Hz, 2 H, ArH),
8.06Ϫ8.13 (m, 1 H, ArH). 13C NMR (CDCl3, 75 MHz, 25 °C,
TMS): δ ϭ 21.6, 55.5, 64.2, 111.8, 114.2, 120.5, 124.7, 127.5, 128.4,
129.8, 130.0, 131.5, 133.6, 133.8, 135.6, 138.0, 139.4, 146.3, 160.1.
C22H18FN3O (359.40): calcd. C 73.52, H 5.05, N 11.69; found C
73.45, H 5.01, N 11.77.
1
3044, 2920, 1480, 1441, 1370, 1265, 1081, 760, 694, 516 cmϪ1. H
NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 1.87 (s, 3 H, CH3, E),
2.23 (s, 3 H, CH3, Z), 4.03 (s, 2 H, CH2Cl, Z), 4.32 (s, 2 H, CH2Cl,
E), 6.98Ϫ7.47 (m, 7 H, ArH, E and Z), 8.07Ϫ8.16 (m, 1 H, ArH,
E and Z).
1-[3-Chloro-1-(4-fluorophenyl)-2-(2,5-dimethylphenyl)propenyl]-1H-
benzotriazole [4g (or 4h)]: Viscous liquid; (E)/(Z) (CDCl3) ϭ 2.78:1.
IR (neat): ν˜ ϭ 3040, 2928, 1501, 1477, 1368, 1268, 1077, 756, 691
cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.18 (s, 3
.
H, CH3, E), 2.19 (s, 3 H, CH3, E), 2.25 (s, 3 H, CH3, Z), 2.39 (s,
3 H, CH3, Z), 4.11 (d, J ϭ 11.4 Hz, 1 H of CH2Cl, Z), 4.36 (d,
J ϭ 11.4 Hz, 1 H of CH2Cl, Z), 4.57 (d, J ϭ 11.0 Hz, 1 H of
CH2Cl, E), 4.65 (d, J ϭ 11.0 Hz, 1 H of CH2Cl, E), 6.67Ϫ7.64 (m,
10 H, ArH, E and Z), 7.91 (d, J ϭ 7.9 Hz, 1 H, ArH, E), 8.13Ϫ8.21
(m, 1 H, ArH, Z).
General Procedure for the Synthesis of 4: SOCl2 (0.60Ϫ1.59 mmol)
was added at room temperature to
a
solution of
3
(0.20Ϫ0.53 mmol) in THF (30 mL). The mixture was stirred for
1 h, followed by addition of water (50 mL) and extraction with
CH2Cl2 (30 mL ϫ 3). The extracts were dried with MgSO4. Re-
moval of the solvent in vacuo gave a residue, which was chromato-
graphed on a silica gel column (3 ϫ 10 cm; EtOAc/n-hexane, 1:5)
to give compound 4.
1-[3-Chloro-1-(4-methoxyphenyl)-2-phenylpropenyl]-1H-benzo-
triazole (4j): Viscous liquid; (E)/(Z) (CDCl3) ϭ 1:1.88. IR (neat):
1
ν ϭ 3048, 2912, 1511, 1444, 1388, 1236, 1046, 745, 696 cmϪ1. H
˜
NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 3.68 (s, 3 H, OCH3,
Z), 3.82 (s, 3 H, OCH3, E), 4.30 (s, 2 H, CH2Cl, Z), 4.73 (s, 2 H,
CH2Cl, E), 6.52Ϫ7.49 (m, 12 H, ArH, E and Z), 7.90 (d, J ϭ
7.4 Hz, 1 H, ArH, E), 8.10Ϫ8.17 (m, 1 H, ArH, Z).
(E)-1-(3-Chloro-1,2-diphenylpropenyl)-1H-benzotriazole {(E)-4a [or
˜
(E)-4d]}: M.p. 137Ϫ139 °C (MeOH). IR (KBr): ν ϭ 3048, 2910,
1480, 1436, 1376, 1259, 1038, 760, 739, 692 cmϪ1 1H NMR
.
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 4.63 (s, 2 H, CH2Cl),
6.98Ϫ7.42 (m, 13 H, ArH), 7.85 (d, J ϭ 7.1, 1 H, ArH). 13C NMR
(CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 46.6, 110.6, 120.3, 124.3,
128.1, 128.3, 128.8, 128.9, 129.0, 129.5, 130.4, 133.6, 135.4, 135.8,
136.7, 137.6, 145.8. C21H16ClN3 (345.82): calcd. C 72.93, H 4.66,
N 12.15; found C 72.85, H 4.73, N 12.05.
1-[3-Chloro-1-(4-methoxyphenyl)-2-(4-tolyl)propenyl]-1H-benzo-
triazole (4k): Viscous liquid; (E)/(Z) (CDCl3) ϭ 1:2.04. IR (neat):
Ϫ1
˜
ν ϭ 3048, 2920, 1512, 1442, 1370, 1254, 1038, 926, 742, 691 cm
.
1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.18 (s, 3 H, CH3,
E), 2.36 (s, 3 H, CH3, Z), 3.70 (s, 3 H, OCH3, Z), 3.84 (s, 3 H,
OCH3, E), 4.29 (s, 2 H, CH2Cl, Z), 4.73 (s, 2 H, CH2Cl, E),
6.57Ϫ7.48 (m, 11 H, ArH, E and Z), 7.95 (d, J ϭ 8.1 Hz, 1 H,
ArH, E), 8.09Ϫ8.17 (m, 1 H, ArH, Z).
(Z)-1-(3-Chloro-1,2-diphenylpropenyl)-1H-benzotriazole {(Z)-4a [or
(Z)-4d]}: M.p. 142Ϫ144 °C (MeOH). IR (KBr): ν˜ ϭ 3048, 2928,
1478, 1438, 1377, 1270, 1048, 756, 745, 699 cmϪ1 1H NMR
.
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 4.26 (s, 2 H, CH2Cl),
General Procedure for the Synthesis of 5: Sodium (0.51Ϫ1.38 mmol)
6.83Ϫ7.35 (m, 13 H, ArH), 8.03Ϫ8.12 (m, 1 H, ArH). 13C NMR was placed in absolute EtOH (15 mL), followed by addition of thiol
(CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 45.2, 111.2, 120.5, 124.8, (0.51Ϫ1.38 mmol). The mixture was stirred for 5 min, followed by
Eur. J. Org. Chem. 2002, 493Ϫ502
497

T. Kim, K. Kim, Y. J. Park
FULL PAPER
addition of a solution of 4 (0.17Ϫ0.46 mmol) in THF (30 mL) at 1-[1-(4-Fluorophenyl)-2-methyl-3-(phenylsulfanyl)propenyl]-1H-
room temperature. The mixture was additionally stirred for 2Ϫ5 h,
benzotriazole (5f): Viscous liquid; (E)/(Z) (CDCl3) ϭ 7.00:1. IR
followed by addition of water (50 mL) and extraction with CH2Cl2 (neat): ν ϭ 3038, 2912, 1571, 1512, 1488, 1294, 1210, 1085, 745,
˜
1
(30 mL ϫ 3). The extracts were dried with MgSO4. Removal of the
solvent in vacuo gave a residue, which was chromatographed on a
silica gel column (3 ϫ 10 cm; EtOAc/n-hexane, 1:5) to give com-
pound 5.
692 cmϪ1. H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 1.83 (s,
3 H, CH3, E), 2.20 (s, 3 H, CH3, Z), 3.65 (s, 2 H, CH2S, Z), 3.89
(s, 2 H, CH2S, E), 6.64Ϫ7.38 (m, 12 H, ArH, E and Z), 8.01Ϫ8.11
(m, 1 H, ArH, E and Z).
(E)-1-[1,2-Diphenyl-3-(phenylsulfanyl)propenyl]-1H-benzotriazole 1-[2-(2,5-Dimethylphenyl)-1-(4-fluorophenyl)-3-(phenylsulfanyl)-
˜
[(E)-5a]: M.p. 136Ϫ138 °C (MeOH). IR (KBr): ν ϭ 3048, 2910, propenyl]-1H-benzotriazole (5g): Viscous liquid; (E)/(Z) (CDCl3) ϭ
1473, 1436, 1374, 1152, 1084, 736, 696 cmϪ1
.
1H NMR (CDCl3,
2.81:1. IR (neat): ν˜ ϭ 3042, 2924, 1594, 1476, 1242, 1080, 904, 746,
300 MHz, 25 °C, TMS): δ ϭ 4.26 (s, 2 H, CH2S), 7.04Ϫ7.41 (m, 694 cmϪ1. H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.14 (s,
1
18 H, ArH), 7.91 (d, J ϭ 8.1 Hz, 1 H, ArH). 13C NMR (CDCl3, 3 H, CH3, E), 2.22 (s, 3 H, CH3, Z), 2.24 (s, 3 H, CH3, E), 2.35 (s,
75 MHz, 25 °C, TMS): δ ϭ 40.3, 110.6, 120.2, 124.2, 127.4, 128.5,
128.6, 128.7, 128.9, 129.1, 129.2, 129.5, 129.8, 130.6, 131.4, 133.7,
135.8, 135.9, 137.8, 138.5, 145.6. C27H21N3S (419.54): calcd. C
3 H, CH3, Z), 3.64 (d, J ϭ 12.9 Hz, 1 H of CH2S, Z), 4.08 (d, J ϭ
12.9 Hz, 1 H of CH2S, Z), 4.10 (d, J ϭ 11.8 Hz, 1 H of CH2S, E),
4.30 (d, J ϭ 11.8 Hz, 1 H of CH2S, E), 6.69Ϫ7.51 (m, 15 H, ArH,
77.30, H 5.05, N 10.02, S, 7.64; found C 77.19, H 5.11, N 10.08, E and Z), 7.90 (d, J ϭ 8.1 Hz, 1 H, ArH, E), 8.12Ϫ8.19 (m, 1 H,
S, 7.61.
ArH, Z).
(Z)-1-[1,2-Diphenyl-3-(phenylsulfanyl)propenyl]-1H-benzotriazole
1-[2-(2,5-Dimethylphenyl)-1-(4-fluorophenyl)-3-(4-methoxyphenyl-
[(Z)-5a]: M.p. 175Ϫ178 °C (CH2Cl2/n-hexane). IR (KBr): ν˜ ϭ 3040, sulfanyl)propenyl]-1H-benzotriazole (5h): Viscous liquid; (E)/(Z)
2915, 1472, 1435, 1377, 1268, 1212, 1049, 755, 692 cmϪ1. 1H NMR
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 3.90 (s, 2 H, CH2S), 1226, 1135, 1082, 744, 696 cmϪ1. H NMR (CDCl3, 300 MHz, 25
6.78Ϫ7.38 (m, 18 H, ArH), 7.98Ϫ8.03 (m, 1 H, ArH). 13C NMR
°C, TMS): δ ϭ 2.15 (s, 3 H, CH3, E), 2.21 (s, 3 H, CH3, Z), 2.24
(CDCl3) ϭ 1.12:1. IR (neat): ν ϭ 3040, 2912, 1597, 1488, 1426,
˜
1
(CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 40.2, 111.4, 120.3, 124.5, (s, 3 H, CH3, E), 2.36 (s, 3 H, CH3, Z), 3.53 (d, J ϭ 13.1 Hz, 1 H
127.2, 128.3, 128.5, 128.6, 128.8, 129.0, 129.1, 130.0, 131.4, 133.9, of CH2S, Z), 3.69 (s, 3 H, OCH3, Z), 3.78 (s, 3 H, OCH3, E), 3.97
135.8, 136.0, 138.7, 139.1, 146.2 (signals of two aromatic C atoms (d, J ϭ 12.2 Hz, 1 H of CH2S, E), 4.07 (d, J ϭ 13.1 Hz, 1 H of
not visible). C27H21N3S (419.54): calcd. C 77.30, H 5.05, N 10.02,
S 7.64; found C 77.24, H 5.12, N 10.10, S 7.69.
CH2S, Z), (d, J ϭ 12.2 Hz, 1 H of CH2S, E), 6.49Ϫ7.50 (m, 14 H,
ArH, E and Z), 7.89 (d, J ϭ 8.2 Hz, 1 H, ArH, E), 8.10Ϫ8.19 (m,
1 H, ArH, Z).
1-[1-Phenyl-3-phenylsulfanyl-2-(4-tolyl)propenyl]-1H-benzotriazole
˜
(5b): Viscous liquid; (E)/(Z) (CDCl3) ϭ 2.46:1. IR (neat): ν ϭ 3042,
(E)-1-[1-(4-Fluorophenyl)-2-methyl-3-(propylsulfanyl)propenyl]-1H-
2920, 1480, 1433, 1382, 1245, 1087, 744, 691 cmϪ1
.
1H NMR benzotriazole [(E)-5i]: M.p. 136Ϫ138 °C (CH2Cl2/n-hexane). IR
˜
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.18 (s, 3 H, CH3, E), 2.34 (KBr): ν ϭ 3040, 2912, 1575, 1502, 1490, 1294, 1208, 1087, 746,
1
(s, 3 H, CH3, Z), 3.96 (s, 2 H, CH2S, Z), 4.29 (s, 2 H, CH2S, E), 691 cmϪ1. H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 0.96 (t,
6.83Ϫ7.49 (m, 17 H, ArH, E and Z), 7.95 (d, J ϭ 7.3 Hz, 1 H,
ArH, E), 8.09 (d, J ϭ 7.2 Hz, 1 H, ArH, Z).
J ϭ 7.3 Hz, 3 H, CH2CH2CH3), 1.44Ϫ1.59 (m, 2 H, CH2CH2CH3),
1.82 (s, 3 H, CH3), 2.55 (t, J ϭ 7.3 Hz, 2 H, CH2CH2CH3), 3.49
(s, 2 H, CH2S), 7.03 (t, J ϭ 8.7 Hz, 2 H, ArH), 7.20 (d, J ϭ 8.0 Hz,
1 H, ArH), 7.29Ϫ7.42 (m, 4 H, ArH), 8.09 (d, J ϭ 8.1 Hz, 1 H,
ArH). 13C NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 13.8, 18.7,
23.2, 34.9, 36.3, 110.6, 116.1 (2JCϪF ϭ 21.7 Hz), 120.5, 124.4, 128.3,
131.3 (3JCϪF ϭ 8.3 Hz), 131.4, 131.9 (4JCϪF ϭ 3.4 Hz), 133.5,
136.9, 146.0, 163.1 (1JCϪF ϭ 248.2 Hz). C19H20FN3S (341.45):
calcd. C 66.83, H 5.90, N 12.31, S 9.39; found C 66.88, H 5.83, N
12.39, S 9.30.
1-[3,3-Dimethyl-1-phenyl-2-(phenylsulfanylmethyl)but-1-enyl]-1H-
benzotriazole (5c): Viscous liquid; (E)/(Z) (CDCl3) ϭ 1.54:1. IR
(neat): ν˜ ϭ 3048, 2912, 1475, 1435, 1376, 1250, 1226, 1154, 1072,
746, 694 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
1.10 [s, 9 H, C(CH3)3, E], 1.27 [s, 9 H, C(CH3)3, Z], 3.68 (s, 2 H,
CH2S, Z), 3.89 (s, 2 H, CH2S, E), 6.85Ϫ7.48 (m, 13 H, ArH, E
and Z), 7.96 (d, J ϭ 8.3 Hz, 1 H, ArH, E), 8.02 (d, J ϭ 8.3 Hz, 1
H, ArH, Z).
1-[1-(4-Methoxyphenyl)-2-phenyl-3-(phenylsulfanyl)propenyl]-1H-
benzotriazole (5j): Viscous liquid; (E)/(Z) (CDCl3) ϭ 1:1.91. IR
(E)-2-{[3-(Benzotriazol-1-yl)-2,3-diphenylallyl]sulfanyl}ethanol [(E)-
˜
5d]: M.p. 141Ϫ143 °C (CH2Cl2/n-hexane). IR (KBr): ν ϭ 3392,
˜
(neat): ν ϭ 3040, 2912, 1601, 1488, 1450, 1280, 1156, 1088, 746,
3048, 2912, 1601, 1481, 1440, 1376, 1268, 1224, 1153, 1067, 744,
692, 516 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
1
698 cmϪ1. H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 1.85 (s,
3.69 (s, 3 H, OCH3, Z), 3.81 (s, 3 H, OCH3, E), 3.98 (s, 2 H, CH2S,
Z), 4.31 (s, 2 H, CH2Cl, E), 6.53Ϫ7.51 (m, 17 H, ArH, E and Z),
7.92 (d, J ϭ 7.4 Hz, 1 H, ArH, E), 8.06Ϫ8.14 (m, 1 H, ArH, Z).
1 H, CH2CH2OH), 2.65 (t, J ϭ 5.9, 2 H, CH2CH2OH), 3.48Ϫ3.60
(m, 2 H, CH2CH2OH), 3.90 (s, 2 H, CH2S), 7.03Ϫ7.56 (m, 13 H,
ArH), 7.93 (d, J ϭ 8.0 Hz, 1 H, ArH). 13C NMR (CDCl3, 75 MHz,
25 °C, TMS): δ ϭ 35.7, 60.9, 111.1, 120.5, 124.8, 128.5, 128.6,
1-[1-(4-Methoxyphenyl)-3-phenylsulfanyl-2-(4-tolyl)propenyl]-1H-
128.7, 128.9, 129.0, 129.9, 133.4, 134.0, 135.7, 138.6, 140.1, 146.2. benzotriazole (5k): Viscous liquid; (E)/(Z) (CDCl3) ϭ 1:2.06. IR
˜
C23H21N3OS (387.50): calcd. C 71.29, H 5.46, N 10.84, S 8.28; (neat): ν ϭ 3042, 2920, 1599, 1487, 1444, 1276, 1215, 1078, 742,
found C 71.38, H 5.50, N 10.77, S 8.20.
694, 518 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
2.17 (s, 3 H, CH3, E), 2.35 (s, 3 H, CH3, Z), 3.70 (s, 3 H, OCH3,
Z), 3.81 (s, 3 H, OCH3, E), 3.94 (s, 2 H, CH2S, Z), 4.30 (s, 2 H,
CH2S, E), 6.55Ϫ7.40 (m, 16 H, ArH, E and Z), 7.94 (d, J ϭ 8.0 Hz,
1 H, ArH, E), 8.06Ϫ8.14 (m, 1 H, ArH, Z).
1-[1-(4-Fluorophenyl)-2-phenyl-3-(phenylsulfanyl)propenyl]-1H-
benzotriazole (5e): Viscous liquid; (E)/(Z) (CDCl3) ϭ 5.54:1. IR
(neat): ν˜ ϭ 3040, 2918, 1489, 1421, 1382, 1266, 1221, 1065, 754,
1
691 cmϪ1. H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 3.99 (s,
2 H, CH2S, Z), 4.26 (s, 2 H, CH2S, E), 6.70Ϫ7.51 (m, 17 H, ArH, General Procedure for the Synthesis of
6 and 12: mCPBA
E and Z), 7.93 (d, J ϭ 8.2 Hz, 1 H, ArH, E), 8.11Ϫ8.18 (m, 1 H, (0.12Ϫ0.35 mmol) was added at room temperature to a solution of
ArH, Z).
5 (0.12Ϫ0.35 mmol) in CH2Cl2 (25 mL). The mixture was stirred
Eur. J. Org. Chem. 2002, 493Ϫ502
498

Synthesis of 2,3-Benzo-1,3a,6a-triazapentalenes
FULL PAPER
for 5 min, followed by addition of aqueous NaHCO3 (10%) and
extraction with CH2Cl2 (30 mL ϫ 3). The combined extracts were
dried with MgSO4. After removal of the solvent in vacuo, the res-
idue was chromatographed on a silica gel column (2 ϫ 10 cm;
EtOAc/n-hexane, 1:1) to give compound 6.
4.25 (d, J ϭ 13.5 Hz, 1 H of CH2S, Z), 4.37 (d, J ϭ 13.0 Hz, 1 H
of CH2S, E), 6.71Ϫ7.75 (m, 17 H, ArH, E and Z), 7.92 (d, J ϭ
8.1 Hz, 1 H, ArH, E), 8.10Ϫ8.18 (m, 1 H, ArH, Z).
1-[3-Benzenesulfinyl-1-(4-fluorophenyl)-2-methylpropenyl]-1H-
benzotriazole (6f): Viscous liquid; (E)/(Z) (CDCl3) ϭ 6.94:1. IR
˜
(neat): ν ϭ 3040, 2920, 1588, 1445, 1226, 1165, 1052, 878, 742, 521
(E)-1-(3-Benzenesulfinyl-1,2-diphenylpropenyl)-1H-benzotriazole
[(E)-6a]: M.p. 148Ϫ150 °C (CH2Cl2/n-hexane). IR (KBr): ν˜ ϭ 3040,
cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 1.85 (s, 3
.
1
2896, 1476, 1438, 1270, 1225, 1073, 1043, 740, 699, 478 cmϪ1. H
H, CH3, E), 2.21 (s, 3 H, CH3, Z), 3.85 (d, J ϭ 12.8 Hz, 1 H of
CH2S, Z), 4.01 (d, J ϭ 13.0 Hz, 1 H of CH2S, E), 4.20 (d, J ϭ
12.8 Hz, 1 H of CH2S, Z), 4.32(d, J ϭ 13.0 Hz, 1 H of CH2S, E),
6.65Ϫ7.41 (m, 12 H, ArH, E and Z), 8.02Ϫ8.11 (m, 1 H, ArH, E
and Z).
NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 4.10 (d, J ϭ 13.0 Hz,
1 H of CH2S), 4.43 (d, J ϭ 13.0 Hz, 1 H of CH2S), 6.99Ϫ7.56 (m,
18 H, ArH) 7.82Ϫ7.88 (m, 1 H, ArH). 13C NMR (CDCl3, 75 MHz,
25 °C, TMS): δ ϭ 64.4, 110.9, 120.2, 124.3, 124.4, 128.2, 128.3,
128.8, 129.1, 129.3, 129.8, 130.1, 130.2, 131.8, 133.2, 133.7, 134.9,
137.4, 137.9, 144.3, 145.7. C27H21N3OS (435.54): calcd. C 74.46, H
4.86, N 9.65, S 7.36; found C 74.54, H 4.90, N 9.59, S 7.33.
1-[3-Benzenesulfinyl-2-(2,5-dimethylphenyl)-1-(4-fluorophenyl)-
propenyl]-1H-benzotriazole (6g): Viscous liquid; (E)/(Z) (CDCl3) ϭ
˜
2.71:1. IR (neat): ν ϭ 3048, 2920, 1598, 1443, 1228, 1181, 1074,
872, 746, 520 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS):
.
(Z)-1-(3-Benzenesulfinyl-1,2-diphenylpropenyl)-1H-benzotriazole
δ ϭ 2.00 (s, 3 H, CH3, E), 2.06 (s, 3 H, CH3, E), 2.34 (s, 3 H, CH3,
Z), 2.45 (s, 3 H, CH3, Z), 3.65 (d, J ϭ 12.6 Hz, 1 H of CH2S, Z),
3.92 (d, J ϭ 12.8 Hz, 1 H of CH2S, E), 4.38 (d, J ϭ 12.8 Hz, 1 H
of CH2S, E), 4.39 (d, J ϭ 12.6 Hz, 1 H of CH2S, Z), 6.75Ϫ7.99
(m, 16 H, ArH, E and Z).
˜
[(Z)-6a]: M.p. 155Ϫ157 °C (CH2Cl2/n-hexane). IR (KBr): ν ϭ 3040,
2912, 1475, 1438, 1374, 1270, 1212, 1080, 1044, 742, 692, 492 cmϪ1
.
1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 3.96 (d, J ϭ
13.6 Hz, 1 H of CH2S), 4.30 (d, J ϭ 13.6 Hz, 1 H of CH2S),
6.87Ϫ7.39 (m, 18 H, ArH) 8.02Ϫ8.09 (m, 1 H, ArH). 13C NMR
(CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 65.6, 112.0, 120.3, 124.1,
124.9, 128.5, 128.7, 128.8, 129.1, 129.4, 129.6, 130.1, 130.2, 131.6,
133.0, 134.0, 135.3, 136.6, 139.1, 144.3, 146.3. C27H21N3OS
(435.54): calcd. C 74.46, H 4.86, N 9.65, S 7.36; found C 74.40, H
4.91, N 9.57, S 7.40.
(E)-1-[2-(2,5-Dimethylphenyl)-1-(4-fluorophenyl)-3-(4-methoxy-
benzenesulfinyl)propenyl]-1H-benzotriazole [(E)-6h]: M.p. 97Ϫ99 °C
˜
(CH2Cl2/n-hexane). IR (KBr): ν ϭ 3040, 2912, 1700, 1587, 1486,
1444, 1294, 1248, 1156, 1048, 828, 740, 520 cmϪ1 1H NMR
.
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 1.99 (s, 3 H, CH3 of major),
2.07 (s, 3 H, CH3 of minor), 2.31 (s, 3 H, CH3 of minor), 2.42 (s,
3 H, CH3 of major), 3.62 (d, J ϭ 12.6 Hz, 1 H, CH2S of major),
3.83 (s, 3 H, OCH3 of major and minor), 3.93 (d, J ϭ 12.7 Hz, 1
H, CH2S of minor), 4.34 (d, J ϭ 12.7 Hz, 1 H, CH2S of minor),
4.38 (d, J ϭ 12.6 Hz, 1 H, CH2S of major), 6.72Ϫ7.95 (m, 15 H,
ArH of major and minor). C30H26FN3O2S (511.61): calcd. C 70.43,
H 5.12, N 8.21, S 6.27; found C 70.48, H 5.21, N 8.18, S 6.35.
1-[3-Benzenesulfinyl-1-phenyl-2-(4-tolyl)propenyl]-1H-benzotriazole
(6b): Viscous liquid; (E)/(Z) (CDCl3) ϭ 2.38:1. IR (neat): ν˜ ϭ 3040,
2942, 1588, 1476, 1433, 1351, 1263, 1071, 861, 749, 516 cmϪ1. H
1
NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.18 (s, 3 H, CH3, E),
2.31 (s, 3 H, CH3, Z), 3.93 (d, J ϭ 12.9 Hz, 1 H of CH2S, Z), 4.10
(d, J ϭ 13.0 Hz, 1 H of CH2S, E), 4.22 (d, J ϭ 12.9 Hz, 1 H of
CH2S, Z), 4.41 (d, J ϭ 13.0 Hz, 1 H of CH2S, E), 6.86Ϫ7.68 (m,
17 H, ArH, E and Z), 7.93 (d, J ϭ 7.2 Hz, 1 H, ArH, E), 8.12 (d,
J ϭ 7.2 Hz, 1 H, ArH, Z).
(Z)-1-[2-(2,5-Dimethylphenyl)-1-(4-fluorophenyl)-3-(4-methoxy-
benzenesulfinyl)propenyl]-1H-benzotriazole [(Z)-6h]: M.p. 152Ϫ154
˜
°C (CH2Cl2/n-hexane). IR (KBr): ν ϭ 3040, 2920, 1704, 1588, 1488,
1-(2-Benzenesulfinylmethyl-3,3-dimethyl-1-phenylbut-1-enyl)-1H-
benzotriazole (6c): Viscous liquid; (E)/(Z) (CDCl3) ϭ 1.48:1. IR
1
1444, 1294, 1248, 1160, 1081, 1041, 827, 744, 518 cmϪ1. H NMR
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.10 (s, 3 H, CH3 of major),
2.22 (s, 3 H, CH3 of minor), 2.33 (s, 3 H, CH3 of minor), 2.42 (s,
3 H, CH3 of major), 3.54 (d, J ϭ 12.9 Hz, 1 H, CH2S of minor),
3.77 (d, J ϭ 12.8 Hz, 1 H, CH2S of major), 3.75 (s, 3 H, OCH3 of
major), 3.80 (s, 3 H, OCH3 of minor), 4.03 (d, J ϭ 12.9 Hz, 1 H,
CH2S of minor), 4.39 (d, J ϭ 12.8 Hz, 1 H, CH2S of major),
6.69Ϫ7.56 (m, 14 H, ArH of major and minor), 8.07Ϫ8.16 (m, 1
H, ArH of major and minor). C30H26FN3O2S (511.61): calcd. C
70.43, H 5.12, N 8.21, S 6.27; found C 70.39, H 5.17, N 8.25,
S 6.24.
˜
(neat): ν ϭ 3048, 2952, 1603, 1473, 1436, 1363, 1265, 1232, 1078,
1
1043, 740, 686 cmϪ1. H NMR (CDCl3, 300 MHz, 25 °C, TMS):
δ ϭ 1.14 [s, 9 H, C(CH3)3, E], 1.23 [s, 9 H, C(CH3)3, Z], 3.71 (d,
J ϭ 13.9 Hz, 1 H of CH2S, Z), 3.83 (d, J ϭ 13.9 Hz, 1 H of CH2S,
Z), 4.12 (s, 2 H, CH2S, E), 6.98Ϫ7.57 (m, 13 H, ArH, E and Z),
7.96Ϫ8.07 (m, 1 H, ArH, E and Z).
(E)-2-[3-(Benzotriazol-1-yl)-2,3-diphenylprop-2-ene-1-sulfinyl]-
ethanol [(E)-6d]: M.p. 120Ϫ122 °C (CH2Cl2/n-hexane). IR (KBr):
˜
ν ϭ 3380, 3040, 2912, 1600, 1480, 1441, 1280, 1226, 1080, 1038,
744, 696 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
(E)-1-[1-(4-Fluorophenyl)-2-methyl-3-(propanesulfinyl)propenyl]-1H-
benzotriazole [(E)-6i]: M.p. 128Ϫ130 °C (CH2Cl2/n-hexane). IR
2.73Ϫ2.98 (m, 2 H, CH2CH2OH), 3.05 (s, 1 H, CH2CH2OH),
4.01Ϫ4.19 (m, 2 H, CH2CH2OH), 4.12 (d, J ϭ 12.9 Hz, 1 H of
CH2S), 4.47 (d, J ϭ 12.9 Hz, 1 H of CH2S), 7.05Ϫ7.67 (m, 13 H,
ArH), 7.92 (d, J ϭ 7.9 Hz, 1 H, ArH). 13C NMR (CDCl3, 75 MHz,
25 °C, TMS): δ ϭ 53.8, 57.3, 60.1, 111.7, 120.4, 125.0, 128.7, 128.8,
128.9, 129.3, 129.4, 130.0, 130.1, 132.9, 133.9, 135.1, 136.5, 138.5,
146.3. C23H21N3O2S (403.50): calcd. C 68.46, H 5.25, N 10.41, S
7.95; found C 68.51, H 5.22, N 10.49, S 7.90.
˜
(KBr): ν ϭ 3040, 2912, 1601, 1490, 1448, 1290, 1242, 1180, 1040,
841, 746 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
1.10 (t, J ϭ 7.3 Hz, 3 H, CH2CH2CH3), 1.72Ϫ1.90 (m, 2 H,
CH2CH2CH3), 1.91 (s, H, CH3), 2.63Ϫ2.82 (m, H,
.
3
2
CH2CH2CH3), 3.55 (d, J ϭ 12.5 Hz, 1 H of CH2S), 3.94 (d, J ϭ
12.5 Hz, 1 H of CH2S), 7.03 (t, J ϭ 8.4 Hz, 2 H, ArH), 7.17Ϫ7.58
(m, 5 H, ArH), 8.06 (d, J ϭ 8.0 Hz, 1 H, ArH). 13C NMR (CDCl3,
1-[3-Benzenesulfinyl-1-(4-fluorophenyl)-2-phenylpropenyl]-1H- 75 MHz, 25 °C, TMS): δ ϭ 13.7, 16.6, 19.6, 55.3, 58.4, 110.9, 116.3
benzotriazole (6e): Viscous liquid; (E)/(Z) (CDCl3) ϭ 5.42:1. IR
(2JCϪF ϭ 21.7 Hz), 120.3, 124.6, 128.6, 130.6, 130.9 (4JCϪF
3.5 Hz), 132.1 (3JCϪF ϭ 8.3 Hz), 133.4, 135.5, 145.3, 163.4
ϭ
˜
(neat): ν ϭ 3042, 2928, 1592, 1447, 1288, 1236, 1080, 869, 744, 517
cmϪ1. 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 3.94 (d, J ϭ (1JCϪF ϭ 248.6 Hz). C19H20FN3OS (357.45): C 63.84, H 5.64, N
13.5 Hz, 1 H of CH2S, Z), 4.07 (d, J ϭ 13.0 Hz, 1 H of CH2S, E), 11.76, S 8.97; C 63.90, H 5.61, N 11.72, S 9.02.
Eur. J. Org. Chem. 2002, 493Ϫ502
499

T. Kim, K. Kim, Y. J. Park
FULL PAPER
1-[3-Benzenesulfinyl-1-(4-methoxyphenyl)-2-phenylpropenyl]-1H-
benzotriazole (6j): Viscous liquid; (E)/(Z) (CDCl3) ϭ 1:1.85. IR
2944, 1572, 1492, 1460, 1430, 1369, 1214, 1121, 1003, 873, 778,
728, 688 cmϪ1
.
1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
˜
(neat): ν ϭ3048, 2912, 1603, 1490, 1454, 1284, 1218, 1142, 841, 725 1.39 [s, 9 H, (CH3)3C], 6.40 (d, J ϭ 8.2 Hz, 1 H, ArH), 6.73 (t, J ϭ
cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 3.69 (s, 3 7.7 Hz, 1 H, ArH), 7.08Ϫ7.19 (m, 3 H, ArH), 7.21Ϫ7.31 (m, 3 H,
H, OCH3, Z), 3.80 (s, 3 H, OCH3, E), 3.92 (d, J ϭ 13.5 Hz, 1 H
ArH), 7.52Ϫ7.66 (m, 6 H, ArH). 13C NMR (CDCl3, 75 MHz, 25
.
of CH2S, Z), 4.11 (d, J ϭ 13.0 Hz, 1 H of CH2S, E), 4.25 (d, J ϭ °C, TMS): δ ϭ 32.5, 34.1, 101.7, 110.8, 114.3, 117.6, 118.0, 121.5,
13.5 Hz, 1 H of CH2S, Z), 4.43 (d, J ϭ 13.0 Hz, 1 H of CH2S, E), 126.1, 126.2, 126.3, 129.4, 129.6, 130.2, 131.5, 132.5, 134.9, 136.4,
6.55Ϫ7.66 (m, 17 H, ArH, E and Z), 7.91 (d, J ϭ 7.4 Hz, 1 H,
ArH, E), 8.10Ϫ8.18 (m, 1 H, ArH, Z).
146.6. C25H23N3S (397.54): calcd. C 75.53, H 5.83, N 10.57, S 8.07;
found C 75.68, H 5.86, N 10.55, S 8.00.
6-(2-Hydroxyethylsulfanyl)-4,5-diphenyl-2,3-benzo-1,3a,6a-triaza-
1-[3-Benzenesulfinyl-1-(4-methoxyphenyl)-2-(4-tolyl)propenyl]-1H-
benzotriazole (6k): Viscous liquid; (E)/(Z) (CDCl3) ϭ 1:2.02. IR
˜
pentalene (7d): M.p. 162Ϫ164 °C (EtOAc/n-hexane). IR (KBr): ν ϭ
3368, 3048, 2922, 1595, 1494, 1369, 1297, 1196, 1062, 905, 862,
˜
(neat): ν ϭ 3042, 2920, 1596, 1480, 1448, 1275, 1211, 1088, 825,
718, 520 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
740, 516 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
2.98 (t, J ϭ 5.1 Hz, 2 H, CH2CH2OH), 3.72 (t, J ϭ 5.1 Hz, 2 H,
CH2CH2OH), 4.76 (s, 1 H, CH2CH2OH), 6.90 (t, J ϭ 7.9 Hz, 1 H,
ArH), 7.32Ϫ7.43 (m, 12 H, ArH), 7.65 (d, J ϭ 8.5 Hz, 1 H, ArH).
13C NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 41.4, 60.9, 106.0,
111.7, 114.4, 118.0, 119.9, 121.4, 127.0, 127.9, 128.0, 128.4, 128.8,
129.4, 129.5, 130.2, 131.1, 131.2, 146.6. C23H19N3OS (385.48):
calcd. C 71.66, H 4.97, N 10.90, S 8.32; found C 71.62, H 4.94, N
10.95, S 8.31.
2.19 (s, 3 H, CH3, E), 2.33 (s, 3 H, CH3, Z), 3.72 (s, 3 H, OCH3,
Z), 3.81 (s, 3 H, OCH3, E), 3.91 (d, J ϭ 13.5 Hz, 1 H of CH2S, Z),
4.09 (d, J ϭ 13.0 Hz, 1 H of CH2S, E), 4.19 (d, J ϭ 13.5 Hz, 1 H
of CH2S, Z), 4.42 (d, J ϭ 13.0 Hz, 1 H of CH2S, E), 6.57Ϫ7.68
(m, 16 H, ArH, E and Z), 7.93 (d, J ϭ 8.0 Hz, 1 H, ArH, E),
8.08Ϫ8.17 (m, 1 H, ArH, Z).
1-[3-(1-Methyl-1H-imidazole-2-sulfinyl)-1,2-diphenylpropenyl]-1H-
benzotriazole (12): Viscous liquid; (E)/(Z) (CDCl3) ϭ 2.79:1. IR
(neat): ν˜ ϭ 3056, 2928, 1601, 1486, 1441, 1396, 1270, 1209, 1155,
4-(4-Fluorophenyl)-5-phenyl-6-(phenylsulfanyl)-2,3-benzo-1,3a,6a-
˜
triazapentalene (7e): M.p. 197Ϫ199 °C (MeOH). IR (KBr): ν ϭ
1048, 907, 745, 518 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C,
.
3048, 2928, 1596, 1571, 1499, 1465, 1369, 1296, 1217, 1153, 883,
732, 696 cmϪ1. 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 6.94
(t, J ϭ 7.8 Hz, 1 H, ArH), 7.14Ϫ7.27 (m, 7 H, ArH), 7.31Ϫ7.43 (m,
7 H, ArH), 7.47Ϫ7.54 (m, 2 H, ArH), 7.68 (d, J ϭ 8.7 Hz, 1 H,
ArH). 13C NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 103.7, 111.4,
TMS): δ ϭ 3.53 (s, 3 H, CH3, Z), 3.73 (s, 3 H, CH3, E), 4.59 (d,
J ϭ 4.7 Hz, 2 H, CH2S, Z), 4.65 (d, J ϭ 13.2 Hz, 1 H of CH2S,
E), 5.10 (d, J ϭ 13.2 Hz, 1 H of CH2S, E), 6.73Ϫ7.62 (m, 15 H,
ArH and ϭCH, E and Z), 7.93 (d, J ϭ 8.0 Hz, 1 H, ArH, E),
8.08Ϫ8.14 (m, 1 H, ArH, Z).
115.0, 116.7 (2JCϪF ϭ 21.8 Hz), 118.0, 121.2, 124.4 (4JCϪF
3.5 Hz), 126.8, 126.9, 127.8, 128.4, 128.8, 130.0, 131.0, 131.1, 132.3
ϭ
General Procedure for the Synthesis of 7, 9, and 13: TFAA
(0.55Ϫ1.60 mmol) was added at room temperature to a solution of (3JCϪF ϭ 8.4 Hz), 136.0, 147.0, 163.3 (1JCϪF ϭ 248.4 Hz) (signals
6 (0.11Ϫ0.32 mmol) in THF (20 mL). The mixture was stirred for of two aromatic C atoms not visible). C27H18FN3S (435.52): calcd.
1 h at room temperature, followed by addition of aqueous C 74.46, H 4.17, N 9.65, S 7.36; found C 74.41, H 4.15, N 9.68,
NaHCO3 (10%) and extraction with CH2Cl2 (20 mL ϫ 3). The
combined extracts were dried with MgSO4. After removal of the
solvent in vacuo, the residue was chromatographed on a silica gel
column (70Ϫ230 mesh, 3 ϫ 10 cm; EtOAc/n-hexane, 1:5) to give
compound 7.
S 7.32.
4-(4-Fluorophenyl)-5-methyl-6-(phenylsulfanyl)-2,3-benzo-1,3a,6a-
triazapentalene (7f): M.p. 173Ϫ175 °C (MeOH). IR (KBr): ν ϭ
˜
3038, 2912, 1571, 1524, 1486, 1371, 1291, 1217, 1192, 1150, 828,
736, 508 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
2.38 (s, 3 H, 9-H) 6.91 (t, J ϭ 7.8 Hz, 1 H, 13-H), 7.13Ϫ7.41 (m,
9 H, 3, 5, 14, 15, 18, 19, 20, 21, 22-H), 7.58Ϫ7.68 (m, 3 H, 2, 6,
16-H). 13C NMR (CDCl3, 150 MHz, 25 °C, TMS): δ ϭ 9.7 (C-9),
104.0 (C-10), 110.6 (C-14), 114.3 (C-16), 116.2 (J ϭ 21.7 Hz; C-3,
5), 117.2 (C-13), 118.1 (C-7), 120.6 (C-12), 123.1 (C-8), 124.2 (J ϭ
3.4 Hz; C-1), 126.0 (C-15), 126.3 (C-20), 127.1 (C-19, 21), 129.2 (C-
18, 22), 131.0 (J ϭ 8.3 Hz; C-2, 6), 135.4 (C-17), 146.3 (C-11), 162.7
(J ϭ 248.3 Hz; C-4). C22H16FN3S (373.45): calcd. C 70.76, H 4.32,
N 11.25, S 8.59; found C 70.76, H 4.36, N 11.04, S 8.23. Refer to
Figure 1 for numbering the position for the NMR data.
4,5-Diphenyl-6-(phenylsulfanyl)-2,3-benzo-1,3a,6a-triazapentalene
˜
(7a): M.p. 177Ϫ179 °C (MeOH). IR (KBr): ν ϭ 3048, 1595, 1571,
1492, 1464, 1368, 1294, 1193, 864, 718, 696 cmϪ1 1H NMR
.
(300 MHz, CDCl3, 25 °C, TMS): δ ϭ 6.91 (t, J ϭ 7.8 Hz, 1 H,
ArH), 7.15Ϫ7.55 (m, 17 H, ArH), 7.68 (d, J ϭ 8.4 Hz, 1 H, ArH).
13C NMR (75 MHz, CDCl3, 25 °C, TMS): δ ϭ 103.5, 111.7, 114.9,
117.9, 119.2, 121.3, 126.7, 126.8, 127.6, 128.2, 128.3, 128.7, 129.3,
129.4, 129.5, 129.7, 130.3, 131.1, 131.2, 136.1, 147.0 (signals of two
aromatic C atoms not visible). C27H19N3S (417.53): calcd. C 77.67,
H 4.59, N 10.06, S 7.68; found C 77.23, H 4.59, N 10.12, S, 7.85.
5-(2,5-Dimethylphenyl)-4-(4-fluorophenyl)-6-(phenylsulfanyl)-2,3-
benzo-1,3a,6a-triazapentalene (7g): M.p. 153Ϫ155 °C (MeOH). IR
4-Phenyl-6-(phenylsulfanyl)-5-(4-tolyl)-2,3-benzo-1,3a,6a-triaza-
˜
pentalene (7b): M.p. 190Ϫ192 °C (MeOH). IR (KBr): ν ϭ 3048,
˜
(KBr): ν ϭ 3040, 2904, 1595, 1571, 1491, 1465, 1366, 1296, 1219,
2904, 1595, 1571, 1491, 1464, 1368, 1294, 1190, 1088, 864, 819,
1
1152, 1081, 838, 804, 727, 688 cmϪ1. H NMR (CDCl3, 300 MHz,
734, 694, 513 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS):
.
25 °C, TMS): δ ϭ 1.88 (s, 3 H, CH3), 2.29 (s, 3 H, CH3), 6.92Ϫ7.02
(m, 2 H, ArH), 7.05Ϫ7.26 (m, 9 H, ArH), 7.36Ϫ7.47 (m, 3 H,
ArH), 7.54 (d, J ϭ 8.3 Hz, 1 H, ArH), 7.71 (d, J ϭ 8.5 Hz, 1 H,
ArH). 13C NMR (CDCl3, 125 MHz, 25 °C, TMS): δ ϭ 19.4, 20.9,
104.8, 110.9, 114.5, 116.0 (2JCϪF ϭ 21.5 Hz), 117.3, 118.3, 120.7,
124.3 (4JCϪF ϭ 3.1 Hz), 126.3, 126.6, 127.9, 128.4, 128.9, 129.4,
129.8, 129.9, 130.4 (3JCϪF ϭ 8.4 Hz), 132.4, 134.3, 134.9, 135.1,
146.5, 162.5 (1JCϪF ϭ 248.1 Hz). C29H22FN3S (463.57): calcd. C
δ ϭ 2.36 (s, 3 H, CH3), 6.92 (t, J ϭ 7.5 Hz, 1 H, ArH), 7.10Ϫ7.29
(m, 9 H, ArH), 7.35Ϫ7.58 (m, 7 H, ArH), 7.68 (d, J ϭ 8.4 Hz, 1
H, ArH). 13C NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 21.7,
103.4, 111.7, 114.9, 117.8, 119.1, 121.3, 126.6, 126.7, 127.5, 128.2,
128.3, 128.4, 129.3, 129.4, 129.5, 129.7, 130.3, 130.9, 136.2, 138.1,
147.0. C28H21N3S (431.55): calcd. C 77.93, H 4.90, N 9.74, S 7.43;
found C 78.05, H 4.89, N 9.70, S 7.31.
5-(tert-Butyl)-4-phenyl-6-(phenylsulfanyl)-2,3-benzo-1,3a,6a-triaza- 75.14, H 4.78, N 9.06, S 6.92; found C 74.84, H 4.82, N 8.97,
˜
pentalene (7c): M.p. 185Ϫ187 °C (MeOH). IR (KBr): ν ϭ 3046,
S 6.93.
500
Eur. J. Org. Chem. 2002, 493Ϫ502

Synthesis of 2,3-Benzo-1,3a,6a-triazapentalenes
FULL PAPER
5-(2,5-Dimethylphenyl)-4-(4-fluorophenyl)-6-(4-methoxy- (E)-1-(Benzotriazol-1-yl)-2-(1,3-oxathiolan-2-yl)stilbene
[(E)-9]:
˜
phenylsulfanyl)-2,3-benzo-1,3a,6a-triazapentalene
(7h):
M.p. M.p. 158Ϫ160 °C (EtOAc/n-hexane). IR (KBr): ν ϭ 3048, 2928,
˜
1601, 1481, 1438, 1380, 1265, 1208, 1150, 1054, 905, 739, 697 cmϪ1
.
146Ϫ148 °C (MeOH). IR (KBr): ν ϭ 3042, 2920, 1584, 1483, 1368,
1291, 1236, 1171, 1081, 1027, 822, 734, 628, 521 cmϪ1. H NMR
1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 2.66Ϫ2.78 (m, 1
1
(CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 1.83 (s, 3 H, CH3), 2.33 (s, H, 1 H of SCH2), 2.95Ϫ3.08 (m, 1 H, 1 H of SCH2), 3.77Ϫ3.88
3 H, CH3), 3.75 (s, 3 H, OCH3), 6.71Ϫ6.79 (m, 2 H, ArH), (m, 1 H, 1 H of OCH2), 4.13Ϫ4.25 (m, 1 H, 1 H of OCH2), 6.29
6.89Ϫ7.01 (m, 2 H, ArH), 7.05Ϫ7.16 (m, 4 H, ArH), 7.25Ϫ7.32
(s, 1 H, CH), 7.00Ϫ7.09 (m, 3 H, ArH), 7.18Ϫ7.54 (m, 10 H, ArH),
(m, 2 H, ArH), 7.34Ϫ7.45 (m, 3 H, ArH), 7.50 (d, J ϭ 8.3 Hz, 1 7.88 (d, J ϭ 8.3 Hz, 1 H, ArH). 13C NMR (CDCl3, 75 MHz, 25
H, ArH), 7.71 (d, J ϭ 8.4 Hz, 1 H, ArH). 13C NMR (CDCl3, °C, TMS): δ ϭ 34.6, 73.3, 84.4, 110.6, 120.1, 124.1, 127.6, 127.9,
75 MHz, 25 °C, TMS): δ ϭ 19.9, 21.4, 55.7, 107.3, 111.4, 114.7,
128.1, 129.2, 129.7, 130.0, 130.6, 133.5, 134.2, 134.7, 134.9, 141.4,
114.9, 116.5 (2JCϪF ϭ 21.8 Hz), 117.5, 118.6, 121.1, 124.8 (4JCϪF ϭ 145.5. C23H19N3OS (385.48): calcd. C 71.66, H 4.97, N 10.90, S
3.5 Hz), 125.7, 126.7, 127.7, 129.8, 130.3, 130.4, 130.8 (3JCϪF
8.1 Hz), 132.9, 133.0, 143.9, 135.3, 147.0, 159.7, 162.9 (1JCϪF
ϭ
8.32; found C 71.49, H 5.01, N 10.99, S 8.39.
ϭ
(E)-(Benzotriazol-1-yl)-2,3-diphenylacrolein [(E)-13]: M.p. 122 Ϫ124
247.7 Hz). C30H24FN3OS (493.60): calcd. C 73.00, H 4.90, N 8.51,
S 6.50; found C 72.88, H 4.92, N 8.43, S 6.58.
˜
°C (EtOAc/n-hexane). IR (neat): ν ϭ 3048, 2848, 1670, 1592, 1480,
1
1441, 1387, 1316, 1278, 1227, 1072, 1035, 905, 715, 695 cmϪ1. H
NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 6.89 (d, J ϭ 7.1 Hz,
1 H, ArH), 6.96Ϫ7.01 (m, 2 H, ArH), 7.09Ϫ7.18 (m, 3 H, ArH),
7.25Ϫ7.43 (m, 4 H, ArH), 7.49Ϫ7.57 (m, 2 H, ArH), 7.60Ϫ7.68
(m, 1 H, ArH), 8.01 (d, J ϭ 8.0 Hz, 1 H, ArH), 9.97 (s, 1 H, Oϭ
CH). 13C NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 111.1, 120.7,
125.0, 128.8, 128.9, 129.0, 129.2, 129.6, 130.0, 130.6, 131.8, 132.6,
133.5, 136.8, 146.2, 150.1, 192.3. C21H15N3O (325.36): calcd. C
77.52, H 4.65, N 12.91; found C 77.98, H 4.59, N 12.88.
4-(4-Fluorophenyl)-5-methyl-6-(propylsulfanyl)-2,3-benzo-1,3a,6a-
˜
triazapentalene (7i): M.p. 137Ϫ139 °C (MeOH). IR (KBr): ν ϭ
3040, 2944, 1588, 1526, 1486, 1464, 1376, 1296, 1214, 1148, 828,
739, 614 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
1.04 (t, J ϭ 7.3 Hz, 3 H, CH2CH2CH3), 1.59Ϫ1.67 (m, 2 H,
CH2CH2CH3), 2.36 (s, 3 H, CH3) 2.92 (t, J ϭ 7.3 Hz, 2 H,
CH2CH2CH3), 6.85 (t, J ϭ 8.1 Hz, 1 H, ArH), 7.25Ϫ7.39 (m, 4 H,
ArH), 7.56Ϫ7.66 (m, 3 H, ArH). 13C NMR (CDCl3, 75 MHz, 25
°C, TMS): δ ϭ 10.3, 13.6, 23.7, 36.0, 107.1, 110.9, 114.3, 116.6
General Procedure for the Synthesis of 15: A mixture of 7
(0.10Ϫ0.15 mmol) and Raney-Ni (50 mg) in THF (20 mL) was
heated for 15 h at reflux under hydrogen. Removal of the insoluble
materials by filtration followed by evaporation of the solvent, gave
a residue, which was chromatographed on a silica gel column (2 ϫ
10 cm; EtOAc/n-hexane, 1:3) to give compound 15.
(2JCϪF ϭ 21.8 Hz), 117.0, 118.2, 121.0, 122.7, 124.9 (4JCϪF
ϭ
3.5 Hz), 126.3, 131.4 (3JCϪF ϭ 8.1 Hz), 147.0, 163.1 (1JCϪF
ϭ
247.8 Hz). C19H18FN3S (339.43): calcd. C 67.23, H 5.35, N 12.38,
S 9.45; found C 67.27, H 5.32, N 12.45, S 9.45.
4-(4-Methoxyphenyl)-5-phenyl-6-(phenylsulfanyl)-2,3-benzo-1,3a,6a-
˜
triazapentalene (7j): M.p. 166Ϫ168 °C (MeOH). IR (KBr): ν ϭ
2-(4,5-Diphenylpyrazol-1-yl)aniline (15a): Viscous liquid. IR (neat):
ν˜ ϭ 3448, 3344, 3040, 1611, 1500, 1372, 1307, 952, 905, 764, 692
3048, 2920, 1600, 1499, 1465, 1369, 1291, 1248, 1177, 1024, 832,
732, 692 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
cmϪ1 1H NMR (300 MHz, CDCl3, 25 °C, TMS): δ ϭ 4.16 (s, 2
.
3.90 (s, 3 H, OCH3), 6.92 (t, J ϭ 7.7 Hz, 1 H, ArH), 6.97Ϫ7.06
(m, 2 H, ArH), 7.12Ϫ7.49 (m, 14 H, ArH), 7.66 (d, J ϭ 8.5 Hz, 1
H, ArH). 13C NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 55.8,
103.4, 111.5, 114.7, 114.9, 117.7, 119.2, 120.4, 121.3, 126.6, 126.7,
127.7, 127.8, 128.2, 128.6, 129.6, 131.0, 131.4, 131.8, 136.2, 147.0,
160.5. C28H21N3OS (447.55): calcd. C 75.14, H 4.73, N 9.39, S 7.16;
found C 75.03, H 4.70, N 9.33, S 7.16.
H, NH2), 6.57 (t, J ϭ 8.1 Hz, 1 H, ArH), 6.73Ϫ6.86 (m, 2 H,
ArH), 7.07Ϫ7.34 (m, 11 H, ArH), 7.99 (s, 1 H, NϭCH). 13C NMR
(75 MHz, CDCl3, 25 °C, TMS): δ ϭ 117.0, 118.3, 121.8, 126.2,
126.3, 126.8, 128.4, 128.7, 128.8, 128.9, 129.7, 130.1, 130.5, 133.2,
140.5, 140.9, 143.7.
2-(4-tert-Butyl-5-phenylpyrazol-1-yl)aniline (15c): Viscous liquid.
˜
IR (neat): ν ϭ 3440, 3336, 3048, 2944, 1614, 1497, 1456, 1433,
4-(4-Methoxyphenyl)-6-phenylsulfanyl-5-(4-tolyl)-2,3-benzo-1,3a,6a-
1369, 1305, 1219, 960, 763, 744, 696 cmϪ1 1H NMR (CDCl3,
.
˜
triazapentalene (7k): M.p. 175Ϫ177 °C (MeOH). IR (KBr): ν ϭ
300 MHz, 25 °C, TMS): δ ϭ 1.23 (s, 9 H, C(CH3)3], 4.14 (s, 2 H,
NH2), 6.44Ϫ6.52 (m, 1 H, ArH), 6.70 (dd, J ϭ 8.0, 1.2 Hz, 1 H,
ArH), 6.76 (dd, J ϭ 7.8, 1.4 Hz, 1 H, ArH), 6.96Ϫ7.04 (m, 1 H,
ArH), 7.22Ϫ7.32 (m, 5 H, ArH), 7.71 (s, 1 H, NϭCH). 13C NMR
(CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 30.9, 32.3, 116.7, 118.0, 126.5,
128.1, 128.6, 128.7, 129.4, 130.3, 131.3, 132.6, 138.8, 141.1, 143.9.
3048, 2920, 1601, 1568, 1464, 1371, 1291, 1248, 1176, 1024, 864,
820, 734, 684 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS):
.
δ ϭ 2.36 (s, 3 H, CH3), 3.90 (s, 3 H, OCH3), 6.91 (t, J ϭ 8.0 Hz,
1 H, ArH), 6.98Ϫ7.05 (m, 2 H, ArH), 7.09Ϫ7.29 (m, 9 H, ArH),
7.33Ϫ7.48 (m, 4 H, ArH), 7.66 (d, J ϭ 8.4 Hz, 1 H, ArH). 13C
NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 21.7, 55.8, 103.1, 111.5,
114.7, 114.9, 117.6, 119.1, 120.5, 121.3, 126.6, 126.7, 127.4, 127.9,
128.3, 129.5, 129.6, 130.8, 131.8, 136.3, 138.0, 147.0, 160.4.
C29H23N3OS (461.58): calcd. C 75.46, H 5.02, N 9.10, S 6.95; found
C 75.33, H 5.01, N 9.02, S 6.82.
2-[5-(4-Fluorophenyl)-4-methylpyrazol-1-yl]aniline (15i): Viscous li-
quid. IR (neat): ν ϭ 3448, 3336, 3040, 2920, 1614, 1504, 1454, 1372,
˜
1305, 1220, 1153, 961, 833, 747 cmϪ1. 1H NMR (CDCl3, 300 MHz,
25 °C, TMS): δ ϭ 2.16 (s, 3 H, CH3), 4.23 (s, 2 H, NH2), 6.53Ϫ6.62
(m, 1 H, ArH), 6.70 (dd, J ϭ 7.9, 1.5 Hz, 1 H, ArH), 6.81 (dd, J ϭ
8.1, 1.2 Hz, 1 H, ArH), 6.96Ϫ7.05 (m, 2 H, ArH), 7.06Ϫ7.20 (m,
3 H, ArH), 7.65 (s, 1 H, NϭCH). 13C NMR (CDCl3, 75 MHz, 25
°C, TMS): δ ϭ 9.7, 115.5, 115.8 (2JCϪF ϭ 21.4 Hz), 117.1, 118.4,
4,5-Diphenyl-6-(2-trifluoroacetoxyethylsulfanyl)-2,3-benzo-1,3a,6a-
˜
triazapentalene (8): Viscous liquid. IR (neat): ν ϭ 3048, 2920, 1777,
1595, 1494, 1464, 1272, 1359, 1297, 1216, 1156, 905, 864, 715 cmϪ1
.
1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 3.23 (t, J ϭ 6.6 Hz,
2 H, SCH2), 4.36 (t, J ϭ 6.6 Hz, 2 H, OCH2), 6.93 (t, J ϭ 7.7 Hz,
1 H, ArH), 7.27Ϫ7.56 (m, 12 H, ArH), 7.86 (d, J ϭ 8.4 Hz, 1 H,
126.3, 126.5 (4JCϪF ϭ 3.5 Hz), 128.3, 129.5, 131.6 (3JCϪF
8.0 Hz), 140.5, 141.8, 143.5, 162.7 (1JCϪF ϭ 246.8 Hz).
ϭ
ArH). 13C NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 31.6, 66.8, 2-[5-(4-Methoxyphenyl)-4-(p-tolyl)pyrazol-1-yl]aniline (15k): Vis-
˜
cous liquid. IR (neat): ν ϭ 3448, 3352, 3032, 2928, 1608, 1515,
103.9, 111.7, 114.5, 114.6 (CF3, JCϪF ϭ 282.4 Hz), 117.9, 119.4,
121.2, 126.9, 127.0, 127.7, 128.0, 128.4, 128.7, 129.4, 130.2, 130.9, 1496, 1446, 1248, 1176, 950, 814, 747, 728 cmϪ1. 1H NMR (CDCl3,
131.1, 147.0, 157.4 (CϭO, JCϪCF3 ϭ 42.1 Hz).
Eur. J. Org. Chem. 2002, 493Ϫ502
300 MHz, 25 °C, TMS): δ ϭ 2.35 (s, 3 H, CH3), 3.78 (s, 3 H,
501

T. Kim, K. Kim, Y. J. Park
FULL PAPER
OCH3), 4.13 (s, 2 H, NH2), 6.54Ϫ6.63 (m, 1 H, ArH), 6.73Ϫ6.85
(m, 4 H, ArH), 7.04Ϫ7.23 (m, 7 H, ArH), 7.93 (s, 1 H, NϭCH).
6.76Ϫ6.90 (m, 2 H, ArH), 7.03Ϫ7.26 (m, 7 H, ArH), 7.30Ϫ7.43
(m, 2 H, ArH), 7.97 (s, 1 H, NϭCH), 8.38 (d, J ϭ 8.2 Hz, 1 H,
13C NMR (CDCl3, 75 MHz, 25 °C, TMS): δ ϭ 21.6, 55.5, 114.3, ArH), 8.94 (s, 1 H, NH). 13C NMR (CDCl3, 75 MHz, 25 °C, TMS):
117.0, 118.4, 121.4, 122.4, 126.3, 128.2, 128.7, 129.6, 130.4, 131.7,
δ ϭ 21.5, 27.3, 55.5, 114.4, 121.7, 122.2, 128.2, 128.8, 128.9, 129.2,
136.4, 140.4, 140.5, 143.7, 159.8 (signal of one aromatic C atom 129.6, 130.2, 131.3, 132.1, 136.2, 136.5, 137.3, 140.2, 140.4, 160.0,
not visible).
173.8. C25H23N3O2 (397.47): calcd. C 75.54, H 5.83, N 10.57; found
C 75.49, H 5.88, N 10.61.
General Procedure for the Synthesis of 16: Acetic anhydride
(0.10Ϫ0.15 mmol) was added at room temperature to a solution of
15 (0.09Ϫ0.14 mmol) in THF (10 mL). The mixture was heated at
reflux for 7 h, followed by addition of a aqueous NaHCO3 (10%)
and extraction with CH2Cl2 (10 mL ϫ 2). The combined organic
extracts were dried with MgSO4. After removal of the solvent in
vacuo, the residue was chromatographed on a silica gel column (2
ϫ 10 cm; EtOAc/n-hexane, 1:1) to give compound 16.
Acknowledgments
The authors are grateful to the Brain Korea 21 program for finan-
cial support of this work.
[1]
C. G. Newton, C. A. Ramsden, Tetrahedron 1982, 38,
2965Ϫ3011.
[2] [2a]
[2b]
1-(2-Acetamidophenyl)-4,5-diphenylpyrazole (16a): M.p. 117Ϫ119
C. A. Ramsden, Tetrahedron 1977, 33, 3203Ϫ3232.
D. Ollis, S. P. Stanforth, Tetrahedron 1985, 41, 2239Ϫ2329.
W.
[2c]
˜
°C (EtOAc/n-hexane). IR (KBr): ν ϭ 3320, 3040, 2912, 1686, 1590,
1513, 1444, 1366, 1294, 763, 692 cmϪ1 1H NMR (300 MHz,
.
O. Tsuge, T. Hatta, M. Sugaya, E. Yunoki, H. Gau, A. Kakehi,
Heterocycles 1995, 41, 209Ϫ214. [2d] O. Tsuge, H. Samura, Tet-
rahedron Lett. 1973, 597Ϫ600.
CDCl3, 25 °C, TMS): δ ϭ 2.15 (s, 3 H, CH3), 6.75 (d, J ϭ 2.7 Hz,
1 H, ArH), 6.87 (t, J ϭ 7.7 Hz, 1 H, ArH), 7.05Ϫ7.12 (m, 2 H,
ArH), 7.21Ϫ7.46 (m, 9 H, ArH), 8.02 (s, 1 H, NϭCH), 8.37 (d,
J ϭ 8.2 Hz, 1 H, ArH), 8.93 (s, 1 H, NH). 13C NMR (75 MHz,
CDCl3, 25 °C, TMS): δ ϭ 25.4, 122.5, 123.2, 123.9, 126.3, 127.2,
127.6, 128.4, 129.0, 129.10, 129.16, 129.19, 129.6, 130.6, 132.6,
134.1, 141.1, 141.4, 168.9. C23H19N3O (353.42): calcd. C 78.16, H
5.42, N 11.89; found C 78.21, H 5.46, N 11.90.
[3] [3a]
B. M. Lynch, Y.-Y. Hung, J. Heterocycl. Chem. 1965, 2,
[3b]
218Ϫ219.
I. M. McRobbie, O. Meth-Cohn, H. Suschitzky,
Tetrahedron Lett. 1976, 925Ϫ928.
[4] [4a]
O. Tsuge, H. Samura, J. Heterocycl. Chem. 1971, 8,
707Ϫ710. [4b] O. Tsuge, H. Samura, Org. Prep. Procd. Int. 1972,
4, 273Ϫ275.
[4c]
A. J. Nunn, F. J. Rowell, J. Chem. Soc., Perkin
Trans. 1 1975, 629Ϫ631.
[5]
[6]
J. H. Lee, A. Matsumoto, M. Yoshida, O. Simamura, Chem.
Lett. 1974, 951Ϫ954.
1-(2-Acetamidophenyl)-4-tert-butyl-5-phenylpyrazole (16c): M.p.
[6a] J. Elguero, R. M. Claramunt, A. J. H. Summers, Adv. Heter-
˜
141Ϫ143 °C (EtOAc/n-hexane). IR (KBr): ν ϭ 3312, 3048, 2952,
1
1688, 1590, 1516, 1441, 1360, 1294, 1225, 961, 764, 696 cmϪ1. H
[6b]
ocycl. Chem. 1978, 22, 183Ϫ320.
C. Wentrup, Adv. Hetero-
A. Albini, G. F. Bettinetti,
[6c]
NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ 1.24 [s, 9 H, C(CH3)3],
2.14 (s, 3 H, CH3), 6.74Ϫ6.83 (m, 2 H, ArH), 7.13Ϫ7.23 (m, 3 H,
ArH), 7.24Ϫ7.35 (m, 3 H, ArH), 7.76 (s, 1 H, NϭCH), 8.27 (d,
J ϭ 8.2 Hz, 1 H, ArH), 8.79 ϭ (s, 1 H, NH). 13C NMR (CDCl3,
75 MHz, 25 °C, TMS): δ ϭ 25.4, 30.9, 32.2, 122.5, 123.5, 126.3,
127.4, 128.5, 128.8, 129.1, 131.2, 131.4, 132.0, 134.4, 139.4, 141.7,
168.7. C21H23N3O (333.43): calcd. C 75.65, H 6.95, N 12.60; found
C 75.52, 6.97, N 12.54.
cycl. Chem. 1981, 28, 231Ϫ361.
G. Minoli, Chem. Lett. 1981, 331Ϫ334.
[7] [7a]
T. W. G. Solomons, F. W. Fowler, J. Calderazzo, J. Am.
[7b]
Chem. Soc. 1965, 87, 528Ϫ531.
T. W. G. Solomons, C. F.
Voigt, J. Am. Chem. Soc. 1966, 88, 1992Ϫ1994.
H. Koga, M. Hirobe, T. Okamoto, Tetrahedron Lett. 1978,
1291Ϫ1294.
Y. H. Kang, C. J. Lee, K. Kim, J. Org. Chem. 2001, 66,
2149Ϫ2153.
D. H. Williams, I. Fleming, Spectroscopic Methods in Organic
Chemistry, 3rd ed., McGraw-Hill, London, 1980, pp. 74Ϫ152.
The X-ray diffraction data were collected at 293 K with an
EnrafϪNonius CAD 4 diffractometer with graphite-monoch-
[8]
[9]
[10]
[11]
1-(2-Acetamidophenyl)-5-(4-fluorophenyl)-4-methylpyrazole
(16i):
˜
M.p. 161Ϫ163 °C (EtOAc/n-hexane). IR (KBr): ν ϭ 3216, 3000,
2912, 1681, 1590, 1536, 1505, 1451, 1361, 1297, 1217, 1153, 836,
811, 752 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
˚
romated Mo-Kα radiation (λ ϭ 0.71070 A). Crystal data for
¯
2.14 (s, 3 H, COCH3), 2.18 (s, 3 H, CH3), 6.67 (d, J ϭ 7.8 Hz, 1
H, ArH), 6.87 (t, J ϭ 7.5 Hz, 1 H, ArH), 6.97Ϫ7.14 (m, 4 H, ArH),
7.25Ϫ7.34 (m, 1 H, ArH), 7.71 (s, 1 H, NϭCH), 8.37 (d, J ϭ
8.2 Hz, 1 H, ArH), 9.10 (s, 1 H, NH). 13C NMR (CDCl3, 75 MHz,
25 °C, TMS): δ ϭ 9.7, 25.4, 116.2 (2JCϪF ϭ 21.6 Hz), 116.4, 123.2,
123.9, 126.0 (4JCϪF ϭ 3.2 Hz), 127.1, 128.9, 129.1, 131.8 (3JCϪF ϭ
8.4 Hz), 133.9, 141.1, 142.4, 162.9 (1JCϪF ϭ 247.7 Hz), 168.8.
C18H16FN3O (309.34): calcd. C 69.89, H 5.21, N 13.58; found C
69.94, H 5.18, N 13.63.
7f: C22H16FN3S, triclinic, P1, a ϭ 9.534(9), b ϭ 9.721(9), c ϭ
˚
˚
10.832(9) A, α ϭ 69.17(8), β ϭ 72.98(9), γ ϭ 88.83(9)°, V ϭ
893.2(14) A , Z ϭ 2, ρcalcd. ϭ 1.388 gcmϪ3, F(000) ϭ 388, θ ϭ
3
2.11Ϫ21.99°, 2188 measured reflections, 1613 [R(int) ϭ 0.0422]
independent reflections, R(F) ϭ 0.0610 [F Ͼ Iσ(F)], wR ϭ
0.2023, GOF ϭ 1.053. Crystallographic data (excluding struc-
ture factors) for the structure reported in this paper have been
deposited with the Cambridge Crystallographic Data Centre as
supplementary publication no. CCDC-167576. Copies of the
data can be obtained free of charge on application to CCDC,
12 Union Road, Cambridge CB21 EZ, UK [Fax: (internat.)
ϩ 44-1223/336-033; E-mail: deposit@ccdc.cam.ac.uk].
M. Node, K. Nishide, Y. Shigeta, K. Obeta, H. Shiraki, H.
Kunishige, Tetrahedron 1997, 53, 12883Ϫ12894.
1-(2-Acetamidophenyl)-5-(4-methoxyphenyl)-4-(p-tolyl)pyrazole
˜
(16k): M.p. 108Ϫ110 °C (EtOAc/n-hexane). IR (KBr): ν ϭ 3258,
[12]
3008, 1687, 1601, 1515, 1496, 1440, 1364, 1286, 1243, 1179, 950,
760, 726 cmϪ1 1H NMR (CDCl3, 300 MHz, 25 °C, TMS): δ ϭ
.
Received August 9, 2001
2.15 (s, 3 H, COCH3), 2.33 (s, 3 H, CH3), 3.80 (s, 3 H, OCH3),
[O01390]
502
Eur. J. Org. Chem. 2002, 493Ϫ502