Zrcl4-mediated regioselective electrophilic amination of activated arenes with new alkyl arylaminocarbonyldiazenecarboxylates: Intermolecular and intramolecular reactions

Full text of DOI:10.1021/jo9821170

2558
J . Org. Chem. 1999, 64, 2558-2563
Ta ble 1. Oxid a tion of 1,4-Disu bstitu ted Sem ica r ba zid esa
Zr Cl4-Med ia ted Regioselective
to Dia zen es
Electr op h ilic Am in a tion of Activa ted
Ar en es w ith New Alk yl
Ar yla m in oca r bon yld ia zen eca r boxyla tes:
In ter m olecu la r a n d In tr a m olecu la r
Rea ction s†
Ar
R
timeb (min)
product
yieldc (%)
Ph
Ph
Et
i-Bu
Et
Me
Et
Et
50
30
25
45
30
55
25
2a
2b
2c
2d
2e
2f
944
96
98
94
90
97
92
Roman Lenarsˇicˇ, Marijan Kocˇevar, and
Slovenko Polanc*
4-MeC6H4
4-MeOC6H4
4-FC6H4
3-ClC6H4
3,4-ClC6H3
Faculty of Chemistry and Chemical Technology, University
of Ljubljana, Asˇkercˇeva 5, SI-1000 Ljubljana, Slovenia
Bn
2g
Received October 20, 1998
a
Semicarbazides 1a -g were prepared in 90-97% yield by the
addition of aryl isocyanates (ArNCO) to alkoxycarbonylhydrazine
(H2NNHCO2R). b Reactions were carried out at room temperature.
c Isolated yields are given.
In tr od u ction
Azo-diesters have been recognized as reagents for the
amination of electron-rich arenes. A thermal and acid-
catalyzed electrophilic amination of alkylbenzenes and
some substituted phenols, which was published several
decades ago and was limited to dialkyl azodicarboxylates,
required high temperatures or strongly acidic conditions.1
Recently, bis(2,2,2-trichloroethyl) azodicarboxylate was
introduced as an efficient reagent for the synthesis of
aromatic amines.2 We herein report on hitherto unknown
aminations of electron-rich arenes with alkyl arylami-
nocarbonyldiazenecarboxylates.
Our recently reported results on the reactions of mono-
and disubstituted hydrazines demonstrated the variety
of their applications in organic synthesis.3 We also
described a mild approach to 1,3,4-oxadiazoles and fused
1,2,4-triazoles from the corresponding 1,4-disubstituted
semicarbazides via diazenes as intermediates. For ex-
ample, ethyl phenylaminocarbonyldiazenecarboxylate4
smoothly reacted with Ph3P to give 2-ethoxy-5-phenyl-
amino-1,3,4-oxadiazole.5 Herein, we focus our attention
on diazenes with respect to their potential as reagents
for electrophilic amination. Diazenes 2a -g, obtained in
good yields by the oxidation of 1,4-disubstituted semi-
carbazides 1a -g with NBS (Table 1), are stable com-
pounds and can be kept in the refrigerator for months.
There is only one report on diazene 2a and its tert-butyl
derivative dealing with their application in an azo-ene
reaction.4 To the best of our knowledge, diazene 2a has
not been previously used for electrophilic amination of
arenes. Therefore, 2a and new diazenes 2b-g were
employed in this investigation.
Resu lts a n d Discu ssion
Diazenes 2a -g can react with activated arenes under
mild conditions. Our initial studies were devoted to the
selection of the Lewis acid to enable the reaction of 2a
with anisole. Although ZnI2, ZnCl2, BF3‚Et2O, CF3SO3H,
TFA, and LiClO4 have already been used for electrophilic
amination of arenes with bis(2,2,2-trichloroethyl) azodi-
carboxylate,2a-d we found ZrCl4 to be a new reagent for
the electrophilic amination of arenes with diazenes that
was easy to handle and that led to the desired product
in good yield. On the other hand, none of the other Lewis
acids gave satisfactory results when 2a was treated with
anisole. Either this reaction resulted in a complex
mixture of several products (the application of ZnI2,
ZnCl2, BF3‚Et2O, CF3SO3H, or TFA) or the amination was
much slower compared to that carried out in the presence
of ZrCl4 (in the case of LiClO4). For the above reasons,
ZrCl4 was used throughout this paper. In a typical
experiment, a solution of the diazene 2a (1 mmol) and
anisole (1 mmol) in CH2Cl2 (7 mL) was added dropwise
to a stirred suspension of ZrCl4 (1.1 mmol) in CH2Cl2 (2
mL) at -30 °C under argon. After 45 min, the reaction
mixture was warmed to room temperature, quenched
with H2O (5 mL), and neutralized with a saturated
aqueous solution of NaHCO3, and the product 3a was
isolated from CH2Cl2 solution in 85% yield. Similar
experiments of the diazenes 2b-g led to the formation
of the corresponding products 3b-g (Table 2). Reactions
took place with complete regioselectivity concerning both
partners; the nitrogen atom, vicinal to the amide func-
tionality of reagent 2, always attacked para to the anisole
methoxy group. There was no other regioisomer detected
in the crude reaction mixture. This was evident from (i)
1H NMR spectra as only the ortho coupling appeared for
the protons of the aminated anisole moiety and (ii) typical
fragments obtained in mass spectra (M+ - ArNCO). In
addition, anisole derivatives of type 3 could be easily
transformed to 1,2-disubstituted hydrazines, unsym-
metrical ureas, and unsymmetrical 1,2,4-triazoline-3,5-
diones. Selected examples derived from 3a are shown in
* E-mail: slovenko.polanc@uni-lj.si.
† Dedicated with deep respect to Professor Henk C. van der Plas on
the occasion of his 70th birthday.
(1) (a) Huisgen, R.; J akob, F.; Siegel, W.; Cadus, A. Liebigs Ann.
Chem. 1954, 590, 1-36. (b) Carlin, R. B.; Moores, M. S. J . Am. Chem.
Soc. 1962, 84, 4107-4112. (c) Schroeter, S. H. J . Org. Chem. 1969,
34, 4012-4015.
(2) (a) Zaltgender, I.; Leblanc, Y.; Bernstein, M. A. Tetrahedron Lett.
1993, 34, 2441-2444. (b) Mitchell, H.; Leblanc, Y. J . Org. Chem. 1994,
59, 682-687. (c) Leblanc, Y.; Boudreault, N. J . Org. Chem. 1995, 60,
4268-4271. (d) Boudreault, N.; Leblanc, Y. Org. Synth. 1996, 74, 241-
247. (e) Dufrense, C.; Leblanc, Y.; Berthelette, C.; McCooeye, C. Synth.
Commun. 1997, 27, 3613-3624.
(3) (a) Kocˇevar, M.; Susˇin, P.; Polanc, S. Synthesis 1993, 773-774.
(b) Kocˇevar, M.; Mihorko, P.; Polanc, S. Synlett 1995, 241-242. (c)
Kocˇevar, M.; Mihorko, P.; Polanc, S. J . Org. Chem. 1995, 60, 1466-
1469. (d) Sˇtefane, B.; Kocˇevar, M.; Polanc, S. J . Org. Chem. 1997, 62,
7165-7169.
(4) Knight, G. T.; Loadman, M. J . R.; Saville, B.; Wildgoose, J . J .
Chem. Soc., Chem. Commun. 1974, 193-194.
(5) Kosˇmrlj, J .; Kocˇevar, M.; Polanc, S. Synlett 1996, 652-654.
10.1021/jo9821170 CCC: $18.00 © 1999 American Chemical Society
Published on Web 03/16/1999

Notes
J . Org. Chem., Vol. 64, No. 7, 1999 2559
Ch a r t 1a
Ta ble 2. Electr op h ilic Am in a tion of An isole
diazene time (min)a product
Ar
R
yield (%)b
2a
2b
2c
2d
2e
2f
45
90
75
180
30
75
3a
3b
3c
3d
3e
3f
Ph
Ph
4-MeC6H4
4-MeOC6H4 Me
4-FC6H4
3-ClC6H4
Et
i-Bu
Et
85
86
91
87
84
93
76
Et
Et
2g
120
3g
3,4-ClC6H3 Bn
a
Products obtained from: (i) 1,3,5-trimethoxybenzene and 2e
a
Reaction times at -30 °C. Reaction mixtures were then
(7e); (ii) methyl 2,4-dimethoxybenzoate and 2f (8f); (iii) 2-meth-
oxynaphthalene and 2c or 2d (9c, 9d ); (iv) ethyl indole-2-
carboxylate and 2a or 2b (10a , 10b). Experiments were carried
out at -78 °C (for 8f at 0 °C) as described for the synthesis of 3a
from anisole and 2a .
b
allowed to warm to room temperature. Isolated yields are given.
Sch em e 1a
Ta ble 3. In tr a m olecu la r Am in a tion of Dia zen es
diazene timea (h) product
R
R1
R2
yieldb (%)
2a
2b
2c
2d
2e
2f
20
22
17
2
19
21
11a
11b
11c
12d
11e
11f
Et
i-Bu
Et
Me
Et
Et
H
H
H
c
H
Cl
H
H
Me
OMe
F
58
81
58
46
74
62
a
Conditions: (a) 3a (1 mmol), Zn (10 mmol), AcOH (6.5 mL),
reflux, 4 h, 46% of 4a (isolated yield); (b) 3a (1 mmol), PPA (0.94
g), 100 °C, 1 h, 42% of 5a ; (c) 3a (0.5 mmol), NaOH (10 mmol),
H2O-EtOH (1:5, 6 mL), rt, 1 h, 87% of 6a .
H
a
b
Reactions were carried out at room temperature. Isolated
yields are given. c R1 ) N(NHCO2Me)CONHC6H4(4-OMe).
Scheme 1. Compounds 4a and 5a could arise only from
3a and not from other regioisomers.
Sch em e 2
These results stimulated us to perform similar reac-
tions on substrates such as 1,3,5-trimethoxybenzene,
methyl 2,4-dimethoxybenzoate, 2-methoxynaphthalene
and ethyl indole-2-carboxylate. It should be mentioned
that complete regioselectivity on unsymmetrical sub-
strates was again observed. Amination led to the forma-
tion of the products 7-10 (Chart 1).
Diazenes of type 2 suffered an intramolecular reaction
when their CH2Cl2 solutions were treated with ZrCl4 at
room temperature. Namely, diazenes 2a -f cyclized to the
corresponding N-aminobenzimidazole-2-ones of type 11
or 12 (Table 3). It is worth noting that 11f was obtained
as the only regioisomer when 2f was employed as a
starting material. In the case of 2d , an intramolecular
process was presumably followed by an intermolecular
one; the initially formed 11d seems to be sufficiently
activated, as a result of the presence of an electron-
donating methoxy group on the benzene ring, to react
with 2d , giving 12d in the final step (Scheme 2).
Although several experiments were carried out at dif-
ferent temperatures (within the range of -78 °C to room
temperature), all attempts to isolate 11d failed.
the formation of three products: two regioisomers re-
garding the diazene nitrogen, attached directly to the
xylene ring (13 and 14), as well as N-aminobenzimida-
zole-2-one 11a (Scheme 3). An intermolecular process,
which gave almost equal amounts of 13 and 14, obviously
dominated over an intramolecular one. The formation of
11a could not be avoided, although the experiment has
been performed with a 20-fold excess of m-xylene. Similar
amination of toluene with 2a also gave three com-
pounds: 15, 16, and 11a . Aminated toluene derivative
15 was isolated as a minor product, contrary to reactions
of diazenes with more electron-rich arenes, where only
Having the above results in hand, it seemed reasonable
to perform the electrophilic amination of less reactive
arenes for comparison to those already mentioned; m-
xylene, toluene, and benzene have been selected for that
purpose. Thus, a treatment of m-xylene with 2a led to

2560 J . Org. Chem., Vol. 64, No. 7, 1999
Notes
Hz), 7.25 (m, 1H), 7.43 (m, 2H), 7.67 (m, 2H), 8.32 (s, 1H); 13C
NMR (CDCl3) δ 14.1, 65.5, 119.8, 126.1, 129.4, 136.0, 155.2,
161.6.
Sch em e 3
Isob u t yl
p h en yla m in oca r b on yld ia zen eca r b oxyla t e
(2b): mp 50-54 °C (petroleum ether-ethyl acetate); IR 3300,
1750, 1720, 1230 cm-1; 1H NMR δ 0.97 (d, 6H, J ) 6.8 Hz), 2.07
(m, 1H), 4.28 (d, 2H, J 1 ) 6.8 Hz), 7.21 (m, 1H), 7.43 (m, 2H),
7.73 (m, 2H), 11.52 (s, 1H); 13C NMR δ 18.4, 27.3, 74.5, 119.7,
125.1, 129.1, 137.2, 157.0, 161.5; MS (FAB) m/z 250 (M+ + H,
35), 150 (30), 57 (100). Anal. Calcd for C12H15N3O3: C, 57.82;
H, 6.07; N, 16.86. Found: C, 58.08; H, 6.30; N, 16.79.
Eth yl (4-tolyl)a m in oca r bon yld ia zen eca r boxyla te (2c):
mp 66.5-68 °C (toluene); IR 3280, 1760, 1730, 1240 cm-1 1H
;
NMR δ 1.37 (t, 3H, J ) 7.2 Hz), 2.30 (s, 3H), 4.51, (q, 2H, J )
7.2 Hz), 7.23 (m, 2H), 7.62 (m, 2H), 11.44 (s, 1H); 13C NMR δ
13.9, 20.5, 65.3, 119.6, 129.5, 134.3, 134.7, 156.9, 161.4; MS (EI)
m/z 235 (M+, 2), 134 (100), 106 (97); MS (FAB) m/z 236 (M+
+
regioisomers of type 15 were formed. We have differenti-
ated between regioisomers 13 and 14 or between 15 and
16 by mass spectrometry. Products 13 and 15 showed
fragments (M+ - PhNCO); signals for (M+ - ArNCO)
always appeared for the regioisomers of type 3, 7-10,
and 12. On the other hand, mass spectra of aminated
xylene 14 and its toluene analogue 16 exhibited signals
for (M+ - PhNCO) but also peaks that seemed to belong
to (PhNHCONHNHAr)+ as supported by HRMS. (Frag-
ment from 14: C15H17N3O calcd 255.1372, found 255.1364;
fragment from 16: C14H15N3O, calcd 241.1215, found
241.1206). The latter fragmentation has never been
observed for the other regioisomers discussed above.
Finally, a treatment of benzene with 2a in the presence
of ZrCl4 led exclusively to the formation of 11a . Benzene
was obviously not reactive enough to compete with an
intramolecular process that gave benzimidazolone 11a .
H, 63), 107 (35). Anal. Calcd for C11H13N3O3: C, 56.16; H, 5.57;
N, 17.86. Found: C, 56.20; H, 5.67; N, 18.05.
Met h yl (4-m et h oxyp h en yl)a m in oca r b on yld ia zen eca r -
boxyla te (2d ): mp 120-121 °C (petroleum ether-ethyl ac-
etate); IR 3300, 1760, 1720, 1250 cm-1; 1H NMR δ 3.76 (s, 3H),
4.07 (s, 3H), 7.00 (m, 2H), 7.66 (m, 2H), 11.44 (s, 1H); 13C NMR
δ 55.2, 55.6, 114.3, 121.1, 130.2, 156.6, 156.7, 161.9; MS (EI)
m/z 237 (M+, 6), 149 (100), 122 (92); MS (FAB) m/z 238 (M+
H, 21), 123 (30), 55 (100). Anal. Calcd for C10H11N3O4: C, 50.63;
H, 4.67; N, 17.71. Found: C, 50.44; H, 4.61; N, 17.99.
+
Eth yl (4-flu or oph en yl)am in ocar bon yldiazen ecar boxylate
(2e): mp 97-99 °C (toluene); IR 3290, 1750, 1730, 1500, 1240,
1210 cm-1; 1H NMR δ 1.38 (t, 3H, J ) 7.2 Hz), 4.52 (q, 2H, J )
7.2 Hz), 7.28 (m, 2H), 7.76 (m, 2H) 11.58 (s, 1H); 13C NMR δ
13.9, 65.4, 115.8 (d, J ) 22.9 Hz), 121.6 (d, J ) 8.0 Hz), 133.6
(d, J ) 2.5 Hz), 157.0, 159.1 (d, J ) 242.1 Hz), 161.3; MS (EI)
m/z 239 (M+, 6), 138 (100), 110 (89); MS (FAB) m/z 240 (M+
H, 66), 168 (34), 104 (64). Anal. Calcd for C10H10FN3O3: C, 50.21;
H, 4.21; N, 17.57. Found: C, 50.05; H, 4.09; N, 17.72.
+
E t h yl
boxyla te (2f): mp 49.5-50.5 °C (cyclohexane-toluene); IR 3300,
1780, 1740, 1600, 1250 cm-1 1H NMR δ 1.38 (t, 3H, J ) 7.2
Hz), 4.53 (q, 2H, J ) 7.2 Hz), 7.29 (ddd, 1H, J 1 ) 8.0 Hz, J 2
(3-ch lor op h en yl)a m in oca r b on yld ia zen eca r -
Con clu sion
;
In conclusion, diazenes 2 were synthesized and intro-
duced as new and convenient reagents for the regiose-
lective electrophilic amination of various electron-rich
arenes in the presence of ZrCl4. The products can serve
as easily available precursors of a number of aryl-
substituted hydrazines, ureas, 1,2,4-triazolinediones, etc.
In the absence of the arene, intramolecular reaction of 2
takes place. The latter process opens a simple and
general entry to N-aminobenzimidazole-2-ones from aryl
isocyanates via semicarbazides 1 and alkyl arylamino-
carbonyldiazenecarboxylates 2.
)
2.1 Hz, J 3 ) 1.0 Hz), 7.46 (dd, 1H, J 1 ) 8.0 Hz, J 2 ) 8.2 Hz),
7.66 (ddd, 1H, J 1 ) 8.2 Hz, J 2 ) 2.0 Hz, J 3 ) 1.0 Hz), 7.85 (dd,
1H, J 1 ) 2.1 Hz, J 2 ) 2.0 Hz), 11.71 (s, 1H); 13C NMR δ 13.9,
65.5, 118.2, 119.2, 124.9, 130.8, 133.4, 138.7, 157.0, 161.2; MS
(FAB) m/z 256 (M+ + H, 16). Anal. Calcd for C10H10ClN3O3: C,
46.98; H, 3.94; N, 16.44. Found: C, 47.20; H, 3.97; N, 16.36.
Ben zyl (3,4-d ich lor op h en yl)a m in oca r bon yld ia zen eca r -
boxyla te (2g): mp 124-126 °C (petroleum ether-ethyl acetate);
1
IR 3360, 1770, 1740, 1270, 1240 cm-1; H NMR δ 5.54 (s, 2H),
7.45 (m, 5H), 7.69 (m, 2H), 8.00 (dd, 1H, J 1 ) 2.1 Hz, J 2 ) 0.7
Hz), 11.82 (s, 1H); 13C NMR δ 70.5, 119.8, 121.0, 126.9, 128.7,
128.97, 129.00, 131.1, 131.4, 134.1, 137.3, 156.8, 161.0; MS (EI)
m/z 351 (M+, 0.3), 187 (55), 91 (100). Anal. Calcd for C15H11
-
Exp er im en ta l Section
Cl2N3O3: C, 51.16, H, 3.15; N, 11.93. Found: C, 50.89; H, 3.18;
N, 11.98.
Gen er a l. Melting points are uncorrected. IR spectra were
measured as KBr pellets. NMR spectra were recorded at 300.13
and 75.5 MHz, respectively, in DMSO-d6 unless stated otherwise.
Mass spectra were obtained on a VG-Analytical AutospecQ
instrument. Elemental analyses (C, H, N) were performed in
our analytical laboratory.
Typ ica l P r oced u r e for th e Syn th esis of Dia zen es 2. NBS
(0.934 g, 5.25 mmol) was slowly added to a stirred suspension
of semicarbazide 1c (1.186 g, 5 mmol) in CH2Cl2 (25 mL) and
pyridine (0.791 g, 10 mmol) at room temperature. The reaction
mixture was then stirred at room temperature for an additional
25 min, and H2O was added (17 mL), followed by the addition
of concentrated HCl (8 mL). The two phases were separated;
the CH2Cl2 solution was treated with a solution of sodium
thiosulfate pentahydrate (0.5 g) in H2O (25 mL), saturated
aqueous NaHCO3 (25 mL), and H2O (25 mL) and dried over
anhydrous Na2SO4. Solvent was evaporated to dryness to afford
2c (1.150 g, 98% yield). For reaction times and isolated yields
of other products of type 2, see Table 1.
Typ ica l P r oced u r e for th e P r ep a r a tion of 3. A solution
of diazene 2a (221 mg, 1 mmol) and anisole (108 mg, 1 mmol)
in CH2Cl2 (7 mL) was added dropwise to a stirred suspension of
ZrCl4 (257 mg, 1.1 mmol) in CH2Cl2 (2 mL) at -30 °C under
argon. After 45 min, the reaction mixture was warmed to room
temperature, quenched with H2O (5 mL), and neutralized with
saturated NaHCO3. The two phases were separated, and the
aqueous solution was extracted with CH2Cl2 (4 × 5 mL). The
combined CH2Cl2 extracts were then dried over anhydrous Na2-
SO4 and evaporated to dryness. The residue was treated with
petroleum ether-ethyl acetate 5:1 (2 mL), and the solid material
was filtered off to give 3a (280 mg, 85% yield). For reaction
temperatures, reaction times, and isolated yields of other
products, see Table 2.
1-E t h oxyca r b on yl-2-(4-m et h oxyp h en yl)-4-p h en ylsem i-
ca r ba zid e (3a ): mp 132-135 °C (ethyl acetate); IR 3380, 3260,
1
1720, 1690, 1530, 1250 cm-1; H NMR (CDCl3) δ 1.28 (t, 3H, J
) 7.2 Hz), 3.83 (s, 3H), 4.23 (q, 2H, J ) 7.2 Hz), 6.82 (broad s,
E t h yl p h en yla m in oca r b on yld ia zen eca r b oxyla t e (2a ):
mp 80-81 °C (petroleum ether-benzene), lit.4 mp 83-84 °C;
1H NMR (CDCl3) δ 1.46 (t, 3H, J ) 7.2 Hz), 4.54 (q, 2H, J ) 7.2
(6) Dondoni, A.; Barbaro, G.; Battaglia, A. J . Org. Chem. 1977, 21,
3372-3377.

Notes
J . Org. Chem., Vol. 64, No. 7, 1999 2561
1H), 6.93 (m, 2H), 7.04 (m, 1H), 7.11 (s, 1H), 7.26 (m, 2H), 7.37
(m, 2H), 7.44 (m, 2H); 13C NMR δ 14.3, 55.2, 61.0, 113.6, 120.2,
122.4, 126.4, 128.2, 135.3, 139.4, 154.0, 155.7, 157.1; MS (EI)
m/z 329 (M+, 0.2), 210 (100), 137 (66), 122 (36); MS (FAB) m/z
330 (M+ + H, 42), 241 (30), 210 (100), 122 (50). Anal. Calcd for
anhydrous Na2SO4 and evaporated to dryness. The residue was
separated by radial chromatography using petroleum ether-
ethyl acetate (5:3) as a solvent to give the title compound as a
white solid (58 mg, 46%): mp 99.5-100.5 °C (petroleum ether-
1
ethyl acetate); IR 3360, 3240, 1700, 1510, 1230 cm-1; H NMR
C
17H19N3O4: C, 62.00; H, 5.81; N, 12.76. Found: C, 61.81; H,
(CDCl3) δ 1.26 (t, 3H, J ) 7.0 Hz), 3.75 (s, 3H), 4.19 (q, 2H, J )
7.0 Hz), 5.60 (s, 1H), 6.46 (s, 1H), 6.81 (m, 4H); MS (EI) m/z 210
(M+, 82), 137 (100), 122 (55). Anal. Calcd for C10H14N2O3: C,
57.13; H, 6.71; N, 13.33. Found: C, 56.90; H, 6.67; N, 13.42.
1-(4-Meth oxyp h en yl)-3-p h en ylu r ea (5a ). A mixture of 3a
(329 mg, 1 mmol) and polyphosphoric acid (0.94 g) was heated
at 100 °C for 1 h. Water (10 mL) was then added, and the
resulting solution was neutralized with NaHCO3 and extracted
with CH2Cl2 (3 × 15 mL). The combined extracts were dried over
anhydrous Na2SO4 and concentrated under reduced pressure.
The residue was purified by radial chromatography using
petroleum ether-ethyl acetate (5:2) as a solvent to afford 5a as
a white solid (102 mg, 42%): mp 193-194 °C (ethyl acetate),
lit.6 mp 193-194 °C; 1H NMR δ 3.71 (s, 3H), 6.86 (m, 2H), 6.94
(m, 1H), 7.26 (m, 2H), 7.35 (m, 2H), 7.43 (m, 2H), 8.43 (s, 1H),
8.54 (s, 1H); MS (EI) m/z 242 (M+, 81), 123 (100), 108 (91), 93
(69).
1-(Met h oxyp h en yl)-4-p h en yl-1,2,4-t r ia zolin e-3,5-d ion e
(6a ). A solution of 3a (165 mg, 0.5 mmol) and NaOH (40 mg, 10
mmol) in water-ethanol (1:5, 6 mL) was stirred at room
temperature for 1 h. The solution was neutralized with 3 N HCl,
extracted with CH2Cl2 (3 × 10 mL), and dried over anhydrous
Na2SO4. The solvent was evaporated at a reduced pressure to
give 6a as a white solid (88 mg, 87%): mp 172-174 °C (ethyl
acetate), lit.7 mp 174 °C; 13C NMR δ 55.6, 114.6, 121.9, 126.8,
128.4, 129.2, 129.7, 131.7, 150.0, 152.4, 157.3; MS (EI) m/z 283
(M+, 100), 121 (87); HRMS calcd for C15H13N3O3 283.0957, found
283.0966.
6.03; N, 12.62.
1-Isobu toxycar bon yl-2-(4-m eth oxyph en yl)-4-ph en ylsem i-
ca r ba zid e (3b): mp 143.5-145 °C (petroleum ether-ethyl
1
acetate); IR 3380, 3300, 1730, 1670, 1460, 1250 cm-1; H NMR
δ 0.88 (d, 6H, J ) 5.6 Hz), 1.84 (m, 1H), 3.75 (s, 3H), 3.82 (d,
2H, J ) 5.6 Hz), 6.91 (m, 2H), 7.00 (m, 1H), 7.28 (m, 4H), 7.54
(m, 2H), 8.89 (s, 1H), 9.88 (s, 1H); 13C NMR δ 18.8, 27.5, 55.2,
70.8, 113.6, 120.3, 122.4, 126.3, 128.2, 135.3, 139.4, 154.0, 155.9,
157.0; MS (FAB) m/z 358 (M+ + H, 55), 238 (100), 122 (51). Anal.
Calcd for C19H23N3O4: C, 63.85; H, 6.49; N, 11.76. Found: C,
63.90; H, 6.63; 11.71.
1-Eth oxyca r bon yl-2-(4-m eth oxyp h en yl)-4-(4-tolyl)sem i-
ca r ba zid e (3c): mp 167-168 °C (ethyl acetate); IR 3360, 3240,
1750, 1660, 1500, 1240 cm-1 1H NMR δ 1.17 (t, 3H, J ) 7.2
;
Hz), 2.24 (s, 3H), 3.75 (s, 3H), 4.07 (q, 2H, J ) 7.2 Hz), 6.91 (m,
2H), 7.06 (m, 2H), 7.29 (m, 2H), 7.42 (m, 2H), 8.82 (s, 1H), 9.85
(s, 1H); 13C NMR δ 14.3, 20.3, 55.2, 61.0, 113.5, 120.3, 126.3,
128.7, 131.3, 135.4, 136.8, 154.1, 155.7, 157.0; MS (FAB) m/z
344 (M+ + H, 34), 210 (100), 122 (40). Anal. Calcd for
C18H21N3O4: C, 62.96; H, 6.16; N, 12.24. Found: C, 62.88; H,
6.12; N, 12.20.
1-Met h oxyca r b on yl-2,4-b is(4-m et h oxyp h en yl)sem ica r -
ba zid e (3d ): mp 173-176 °C (ethyl acetate); IR 3400, 3280,
1760, 1670, 1510, 1240; 1H NMR δ 3.63 (s, 3H), 3.71 (s, 3H),
3.74 (s, 3H), 6.85 (m, 2H), 6.90 (m, 2H), 7.29 (m, 2H), 7.42 (m,
2H), 8.83 (s, 1H), 9.92 (s, 1H); 13C NMR δ 52.2, 55.1, 55.2, 113.5,
113.6, 122.1, 126.3, 132.4, 135.4, 154.2, 154.9, 156.2, 157.0; MS
(EI) m/z 345 (M+, 2), 196 (100), 137 (36), 122 (44); MS (FAB)
m/z 346 (M+ + H, 47), 196 (100), 122 (66). Anal. Calcd for
C17H19N3O5: C, 59.12; H, 5.55; N, 12.17. Found: C, 59.10; H,
5.62; N, 12.14.
Typ ica l P r oced u r e for th e P r ep a r a tion of Sem ica r ba -
zid es 7-10. Aminated products 7-10 were obtained following
the same procedure as described for the preparation of aminated
anisoles 3, using 1,3,5-trimethoxybenzene, methyl 2,4-dimethox-
ybenzoate, 2-methoxynaphthalene, or ethyl indole-2-carboxylate
instead of anisole. For the selection of the appropriate diazene
of type 2, as well as for reaction temperatures, reaction times,
and isolated yields, see Chart 1.
1-E t h oxyca r b on yl-4-(4-flu or op h e n yl)-2-(4-m e t h oxy-
p h en yl)sem ica r ba zid e (3e): mp 129-131 °C (petroleum
ether-ethyl acetate); IR 3380, 3260, 1730, 1690, 1510, 1260
1
cm-1; H NMR δ 1.20 (t, 3H, J ) 7.2 Hz), 3.75 (s, 3H), 4.07 (q,
1-E t h oxyca r b on yl-4-(4-flu or op h en yl)-2-(2,4,6-t r im et h -
oxyp h en yl)sem ica r ba zid e (7e): mp 118-121 °C (petroleum
ether-ethyl acetate); IR 3380, 1730, 1700, 1620, 1220, 1140
2H, J ) 7.2 Hz), 6.91 (m, 2H), 7.10 (m, 2H), 7.30 (m, 2H), 7.55
(m, 2H), 9.00 (s, 1H), 9.88 (s, 1H); 13C NMR δ 14.3, 55.2, 61.0,
113.6, 114.7 (d, J ) 22.2 Hz), 122.1 (d, J ) 7.6 Hz), 126.4, 135.3,
135.8 (d, J ) 2.2 Hz), 154.2, 155.7, 157.1, 157.7 (d, J ) 238.8
Hz); MS (FAB) m/z 348 (M+ + H, 64), 210 (100), 122 (32). Anal.
Calcd for C17H18FN3O4: C, 58.79; H, 5.22; N, 12.10. Found: C,
59.10; H, 5.36; N, 11.94.
1
cm-1; H NMR δ 1.17 (t, 3H, J ) 7.2 Hz), 3.74 (s, 6H), 3.79 (s,
3H), 4.03 (q, 2H, J ) 7.2 Hz), 6.24 (s, 2H), 7.07 (m, 2H), 7.53
(m, 2H), 8.61 (broad s, 1H), 8.79 (s, 1H); 13C NMR δ 14.4, 55.3,
55.8, 60.5, 91.2, 112.2, 114.7 (d, J ) 21.8 Hz), 121.2 (d, J ) 8.0
Hz), 136.2 (d, J ) 2.9 Hz), 154.2, 155.4, 157.0, 157.4 (d, J )
238.4 Hz), 160.1; MS (FAB) m/z 408 (M+ + H, 21), 319 (47), 270
(100). Anal. Calcd for C19H22FN3O6: C, 56.02; H, 5.44; N, 10.31.
Found: C, 55.89; H, 5.48; N, 10.46.
4-(3-Ch lor op h en yl)-1-eth oxyca r bon yl-2-(2,4-d im eth oxy-
5-m eth oxyca r bon ylp h en yl)sem ica r ba zid e (8f): mp 191-
194 °C (ethyl acetate), IR 3320, 1720, 1700, 1240 cm-1; 1H NMR
δ 1.19 (t, 3H, J ) 7.2 Hz), 3.74 (s, 3H), 3.88 (s, 3H), 3.90 (s, 3H),
4.07 (q, 2H, J ) 7.2 Hz), 6.75 (s, 1H), 7.02 (ddd, 1H, J 1 ) 8.0
Hz, J 2 ) 2.1 Hz, J 3 ) 1.0 Hz), 7.27 (dd, 1H, J 1 ) J 2 ) 8.0 Hz),
7.52 (m, 1H), 7.70 (dd, 1H, J 1 ) J 2 ) 2.1 Hz), 7.81 (s, 1H), 9.01
(s, 1H), 9.63 (s, 1H); 13C NMR δ 14.3, 51.5, 56.1, 56.2, 61.0, 97.3,
110.3, 118.0, 119.1, 121.9, 122.5, 129.9, 132.4, 132.7, 141.2, 154.0,
155.9, 159.6, 160.3, 164.8; MS (FAB) m/z 452 (M+ + H, 32), 298
(100), 210 (34). Anal. Calcd for C20H22ClN3O7: C, 53.16; H, 4.91;
N, 9.30. Found: C, 53.37; H, 4.97; N, 9.01.
1-E t h oxyca r b on yl-4-(3-ch lor op h e n yl)-2-(4-m e t h oxy-
ph en yl)sem icar bazide (3f): mp 139-140 °C (petroleum ether-
1
ethyl acetate); IR 3410, 3200, 1760, 1670, 1510, 1230 cm-1; H
NMR δ 1.20 (t, 3H, J ) 7.2 Hz), 3.76 (s, 3H), 4.08 (q, 2H, J )
7.2 Hz), 6.93 (m, 2H), 7.04 (m, 1H), 7.29 (m, 3H), 7.57 (m, 1H),
7.74 (m, 1H), 9.15 (s, 1H), 9.91 (s, 1H); 13C NMR δ 14.3, 55.2,
61.1, 113.6, 118.3, 119.3, 122.0, 126.5, 129.9, 132.7, 135.0, 141.1,
153.9, 155.7, 157.2; MS (EI) m/z 363 (M+, 0.3), 210 (100), 122
(36); MS (FAB) m/z 364 (M+ + H, 28), 210 (100), 122 (36). Anal.
Calcd for C17H18ClN3O4: C, 56.13; H, 4.99; N, 11.55. Found: C,
56.12; H, 5.01; N, 11.48.
1-Ben zyloxyca r bon yl-4-(3,4-d ich lor op h en yl)-2-(4-m eth -
oxyp h en yl)sem ica r ba zid e (3g): mp 155-157 °C (ethyl ac-
etate); IR 3320, 1740, 1690, 1510, 1260 cm-1; 1H NMR δ 3.76 (s,
3H), 5.12 (s, 2H), 6.92 (m, 2H), 7.29 (m, 7H), 7.52 (d, 1H, J )
8.9 Hz), 7.63 (dd, 1H, J 1 ) 8.9 Hz, J 2 ) 2.5 Hz), 7.93 (d, 1H, J
) 2.5 Hz), 9.31 (s, 1H), 10.11 (s, 1H); 13C NMR δ 55.3, 66.6, 113.7,
119.9, 121.1, 123.8, 126.6, 127.9, 128.1, 128.4, 130.2, 130.6, 134.8,
136.1, 139.8, 153.9, 155.7, 157.4; MS (EI) m/z 459 (M+, 0.4), 272
(37), 137 (98), 91 (100); MS (FAB) m/z 460 (M+ + H, 24), 272
(62), 91 (100). Anal. Calcd for C22H19Cl2N3O4: C, 57.40; H, 4.16;
N, 9.13. Found: C, 57.14; H, 4.08; N, 9.15.
1-Eth oxyca r bon yl-2-(2-m eth oxy-1-n a p h th yl)-4-(4-tolyl)-
sem ica r ba zid e (9c): mp 135-136.5 °C (petroleum ether-ethyl
1
acetate); IR 3440, 3260, 1750, 1700, 1520, 1280, 1240 cm-1; H
NMR δ 1.15 (t, 3H, J ) 7.1 Hz), 2.24 (s, 3H), 3.91 (s, 3H), 4.05
(q, 2H, J ) 7.1 Hz), 7.06 (m, 2H), 7.39 (m, 3H), 7.48 (m, 2H),
7.87 (m, 1H), 7.96 (m, 1H), 8.32 (m, 1H), 8.71 (broad s, 1H), 9.26
(s, 1H); 13C NMR δ 14.3, 20.3, 56.3, 60.8, 114.0, 119.9, 120.0,
123.5, 123.8, 126.3, 127.4, 128.6, 128.7, 129.6, 131.2, 131.9, 137.0,
152.9, 154.9, 156.0; MS (FAB) m/z 394 (M+ + H, 40), 260 (100).
Anal. Calcd for C22H23N3O4: C, 67.16; H, 5.89; N, 10.68. Found:
C, 67.33; H, 5.95; N, 10.78.
2-Eth oxycar bon yl-(4-m eth oxyph en yl)h ydr azin e (4a). Zinc
dust (654 mg, 10 mmol) was added at room temperature to a
solution of 3a (329 mg, 1 mmol) in acetic acid (6.5 mL). The
suspension was heated under reflux for 4 h and cooled to room
temperature, and the solid material was filtered off. The filtrate
was neutralized with 10 N NaOH and extracted with CH2Cl2 (3
× 15 mL). The combined organic extracts were dried over
(7) Wamhoff, H.; Wald, K. Chem. Ber. 1977, 110, 1699-1715.

2562 J . Org. Chem., Vol. 64, No. 7, 1999
Notes
1-Meth oxycar bon yl-2-(2-m eth oxy-1-n aph th yl)-4-(4-m eth -
FN3O3 239.0706, found 239.0712. Anal. Calcd for C10H10FN3O3:
C, 50.21; H, 4.21; N, 17.57. Found: C, 50.13; H, 4.18; N, 17.80.
1-Eth oxyca r bon yla m in o-5-ch lor o-2(3H)-ben zim id a zolo-
n e (11f): mp 214-218 °C (ethyl acetate); IR 3280, 1740, 1720,
1680, 1500, 1270 cm-1; 1H NMR δ 1.25 (t, 3H, J ) 6.8 Hz), 4.15
(q, 2H, J ) 6.8 Hz), 6.95 (d, 1H, J ) 8.9 Hz), 7.06 (d, 1H, J )
2.0 Hz), 7.06 (dd, 1H, J 1 ) 8.9 Hz, J 2 ) 2.0 Hz), 10.28 (s, 1H),
11.21 (broad s, 1H); 13C NMR δ 14.3, 61.5, 108.2, 109.3, 120.8,
125.8, 127.5, 129.0, 152.6, 155.3; MS (EI) m/z 255 (M+, 79), 182
(100), 167 (43); HRMS calcd for C10H10ClN3O3 255.0411, found
255.0418. Anal. Calcd for C10H10ClN3O3: C, 46.98; H, 3.94; N,
16.44. Found: C, 46.83; H, 3.96; N, 16.16.
oxyp h en yl)sem ica r ba zid e (9d ): mp 208-209 °C (ethyl ac-
1
etate); IR 3400, 3360, 1770, 1690, 1520, 1240 cm-1; H NMR δ
3.58 (s, 3H), 3.70 (s, 3H), 3.92 (s, 3H), 6.83 (m, 2H), 7.38 (m,
3H), 7.48 (m, 2H), 7.86 (m, 1H), 7.96 (m, 1H), 8.29 (m, 1H), 8.66
(broad s, 1H), 9.32 (s, 1H); 13C NMR δ 52.0, 55.1, 56.3, 113.5,
114.0, 121.8, 123.6, 123.8, 123.9, 126.3, 127.4, 128.6, 129.6, 132.0,
132.5, 152.9, 154.8, 155.1, 156.5; MS (FAB) m/z 396 (M+ + H,
41), 246 (100), 122 (35). Anal. Calcd for C21H21N3O5: C, 63.79;
H, 5.35; N, 10.63. Found: C, 63.73; H, 5.38; N, 10.49.
1-Eth oxycar bon yl-2-(2-eth oxycar bon yl-3-in dolyl)-4-ph en -
ylsem ica r ba zid e (10a ): mp 189-190 °C (ethyl acetate); IR
3360, 1730, 1680, 1530, 1440, 1230 cm-1; 1H NMR δ 1.17 (t, 3H,
J ) 7.2 Hz), 1.21 (t, 3H, J ) 7.2 Hz), 4.08 (q, 2H, J ) 7.2 Hz),
4.25 (q, 2H, J ) 7.2 Hz), 6.96 (m, 1H), 7.10 (m, 1H), 7.26 (m,
3H), 7.45 (m, 1H), 7.53 (m, 2H), 7.81 (m, 1H), 8.84 (s, 1H), 9.25
(s, 1H), 11.92 (s, 1H); 13C NMR δ 13.9, 14.4, 60.6, 61.0, 112.6,
119.8, 119.9, 120.3, 120.9, 122.3, 122.6, 124.3, 125.0, 128.2, 134.9,
139.7, 154.5, 156.3, 160.7; MS (FAB) m/z 411 (M+ + H, 48), 291
(100), 203 (68). Anal. Calcd for C21H22N4O5: C, 61.46; H, 5.40;
N, 13.65. Found: C, 61.34; H, 5.43; N, 13.63.
1-Met h oxyca r b on yl-2-(6-m et h oxy-1-m et h oxyca r b on yl-
am in o-2(3H)-ben zim idazolon e-5-yl)-4-m eth oxyph en ylsem i-
ca r ba zid e (12d ): mp 231-233 °C (ethyl acetate); IR 3300, 3180,
1720, 1670, 1510, 1240 cm-1 1H NMR δ 3.61 (s, 3H), 3.70 (s,
;
3H), 3.72 (s, 3H), 3.75 (s, 3H), 6.70 (s, 1H), 6.83 (m, 2H), 7.06 (s,
1H), 7.39 (m, 2H), 8.59 (s, 1H), 9.53 (s, 1H), 10.23 (s, 1H), 10.87
(s, 1H); 13C NMR δ 52.1, 52.7, 55.1, 56.4, 92.8, 111.0, 113.5, 118.7,
121.7, 124.7, 130.1, 132.6, 151.2, 152.9, 154.5, 154.8, 155.9, 156.6;
MS (FAB) m/z 475 (M+ + H, 27), 325 (73), 122 (34); HRMS (FAB)
calcd for C20H23N6O8 475.1577, found 475.1593. Anal. Calcd for
2-(2-Eth oxyca r bon yl-3-in d olyl)-1-isobu toxylca r bon yl-4-
p h en ylsem ica r ba zid e (10b): mp 182-184 °C (ethyl acetate);
IR 3360, 1730, 1690, 1540, 1210 cm-1; 1H NMR δ 0.84 (d, 6H, J
) 6.8 Hz), 1.21 (t, 3H, J ) 7.2 Hz), 1.84 (m, 1H), 3.83 (d, 2H, J
) 6.4 Hz), 4.26 (q, 2H, J ) 7.2 Hz), 6.96 (m, 1H), 7.09 (m, 1H),
7.25 (m, 3H), 7.45 (m, 1H), 7.52 (m, 2H), 7.80 (m, 1H), 8.79 (s,
1H), 9.27 (s, 1H), 11.91 (s, 1H); 13C NMR δ 13.9, 18.7, 27.5, 60.6,
70.8, 112.6, 119.8, 119.9, 120.2, 120.8, 122.2, 122.5, 124.2, 124.9,
128.2, 134.8, 139.7, 154.3, 156.3, 160.6; MS (FAB) m/z 439 (M+
+ H, 32), 319 (100), 203 (91). Anal. Calcd for C23H26N4O5: C,
63.00; H, 5.98; N,12.78. Found: C, 63.12; H, 6.10; N, 12.83.
Typ ica l P r oced u r e for th e F or m a tion of 11-12. A solu-
tion of diazene 2b (249 mg, 1 mmol) in CH2Cl2 (7 mL) was added
dropwise to a stirred suspension of ZrCl4 (257 mg, 1.1 mmol) in
CH2Cl2 (2 mL) at room temperature under argon. After 22 h,
the reaction mixture was quenched with H2O (5 mL) and
neutralized with saturated NaHCO3. Isolation of the product,
which was carried out as described above for the synthesis of
3a , led to 11b (201 mg, 81% yield). For reaction times and
isolated yields of other products, see Table 3.
C
20H22N6O8 x 0.5 H2O: C, 49.69; H, 4.80; N, 17.38. Found: C,
49.80; H, 4.71; N, 17.38.
Rea ction of 2a w ith m -Xylen e. A solution of 2a (442 mg, 2
mmol) and m-xylene (4.92 mL, 40 mmol) in CH2Cl2 (14 mL) was
added dropwise to a stirred suspension of ZrCl4 (513 mg, 2.2
mmol) in CH2Cl2 (4 mL) at 0 °C under argon. After 3 h, the
reaction mixture was warmed to room temperature, quenched
with H2O (10 mL), and neutralized with aqueous solution of
NaHCO3. The layers were separated, and the aqueous layer was
extracted with CH2Cl2 (3 × 15 mL). The combined organic layers
were dried over anhydrous Na2SO4, and the solvent was
evaporated under reduced pressure. The products were sepa-
rated by radial chromatography using petroleum ether-ethyl
acetate (5:2) to give 13 (298 mg, 46%), 14 (269 mg, 41%), and
11a (17 mg, 4%).
1-Eth oxyca r bon yl-2-(2,4-d im eth ylp h en yl)-4-p h en ylsem i-
ca r ba zid e (13): mp 64-67 °C (petroleum ether-ethyl acetate);
IR 3410, 3220, 1750, 1680, 1520, 1230 cm-1; 1H NMR δ 1.18 (t,
3H, J ) 7.1 Hz), 2.24 (s, 3H), 2.27 (s, 3H), 4.06 (q, 2H, J ) 7.1
Hz), 6.99 (m, 3H), 7.26 (m, 3H), 7.53 (m, 2H), 8.81 (s, 1H), 9.88
(s, 1H); 13C NMR δ 14.3, 17.7, 20.5, 60.9, 120.1, 122.4, 126.6,
126.9, 128.3, 130.8, 136.0, 136.5, 138.9, 139.5, 153.8, 155.9; MS
(FAB) m/z 328 (M+ + H, 62), 208 (100), 120 (76); HRMS (FAB)
calcd for C18H22N3O3 (M+ + H) 328.1661, found 328.1672. Anal.
Calcd for C18H21N3O3: C, 66.04; H, 6.47; N, 12.84. Found: C,
65.99; H, 6.66; N, 12.68.
1-Eth oxyca r bon yl-1-(2,4-d im eth ylp h en yl)-4-p h en ylsem i-
ca r ba zid e (14): mp 156-157.5 °C (petroleum ether-ethyl
acetate); IR 3300, 1680, 1600, 1540, 1220 cm-1; 1H NMR δ 1.18
(t, 3H J ) 7.1 Hz), 2.24 (s, 3H), 2.26 (s, 3H), 4.10 (q, 2H, J ) 7.1
Hz), 6.99 (m, 3H), 7.25 (m, 2H), 7.33 (d, 1H, J ) 8 Hz), 7.43 (m,
2H), 8.73 (s, 1H), 8.93 (s, 1H); 13C NMR δ 14.6, 17.4, 20.6, 61.9,
118.5, 122.2, 127.0, 127.4, 128.8, 131.0, 134.9, 137.0, 138.9, 139.5,
154.8, 155.2; MS (FAB) m/z 328 (M+ + H, 60), 208 (94), 192 (100),
120 (35). Anal. Calcd for C18H21N3O3: C, 66.04; H, 6.47; N, 12.84.
Found: C, 66.00; H, 6.63; N, 12.81.
1-Eth oxyca r bon yla m in o-2(3H)-ben zim id a zolon e (11a ):
mp 197-199 °C (ethyl acetate); IR 3260, 1740, 1700, 1510, 1260
1
cm-1; H NMR δ 1.25 (t, 3H, J ) 6.9 Hz), 4.15 (q, 2H, J ) 6.9
Hz), 6.99 (m, 4H), 10.14 (s, 1H), 11.00 (s, 1H); 13C NMR δ 14.3,
61.4, 106.9, 109.3, 122.0, 121.7, 126.4, 130.1, 152.7, 155.4; MS
(EI) m/z 221 (M+, 81), 175 (38), 148 (100), 133 (40), 106 (43);
HRMS calcd for C10H11N3O3 221.0800, found 221.0804. Anal.
Calcd for C10H11N3O3: C, 54.30; H, 5.01; N, 19.00. Found: C,
54.06; H, 5.08; N, 18.99.
1-I s o b u t o x y c a r b o n y la m in o -2(3H )-b e n zim id a zo lo n e
(11b): mp 113-118 °C (petroleum ether-ethyl acetate); IR
1
3340, 1710, 1480, 1230 cm-1; H NMR (CDCl3) δ 0.91 (m, 6H),
1.92 (m, 1H), 3.98 (d, 2H, J ) 6.4 Hz), 7.08 (m, 4H), 7.49 (s,
1H), 9.24 (s, 1H); 13C NMR δ 18.7, 27.6, 71.1, 106.9, 109.3, 121.0,
121.7, 126.3, 130.1, 152.7, 155.6; MS (EI) m/z 249 (M+, 51), 149
(100), 133 (30); HRMS calcd for C12H15N3O3 249.1113, found
249.1121. Anal. Calcd for C12H15N3O3: C, 57.82; H, 6.07; N,
16.86. Found: C, 57.64; H, 5.97; N, 16.97.
Rea ction of 2a w ith Tolu en e. This was performed as
described above for the amination of m-xylene, using toluene,
2a , and ZrCl4. Reaction time: 16 h; isolated products: 15 (33
mg, 5%), 16 (267 mg, 41%), and 11a (188 mg, 42%).
1-Eth oxyca r bon yla m in o-6-m eth yl-2(3H)-ben zim id a zolo-
n e (11c): mp 224-228 °C (MeOH); IR 3220, 1750, 1680, 1510,
1230 cm-1; 1H NMR δ 1.25 (t, 3H, J ) 7.0 Hz), 2.30 (s, 3H), 4.14
(q, 2H, J ) 7.0 Hz), 6.74 (m, 1H), 6.83 (ddd, 1H, J 1 ) 7.9 Hz, J 2
) 0.7 Hz, J 3 ) 1.6 Hz), 6.88 (dd, 1H, J 1 ) 7.9 Hz, J 2 ) 0.4 Hz),
10.11 (s, 1H), 10.87 (s, 1H); 13C NMR δ 14.3, 20.9, 61.4, 107.4,
109.0, 122.1, 124.1, 130.1, 130.2, 152.8, 155.4; MS (EI) m/z 235
(M+, 92), 189 (42), 162 (100), 147 (47); HRMS calcd for C11H13N3O3
235.0957, found 235.0962. Anal. Calcd for C11H13N3O3: C, 56.16;
H, 5.57; N, 17.86. Found: 56.21; H, 5.64; N, 17.87.
1-(E t h oxyca r b on yl)-4-p h en yl-2-(4-t olyl)sem ica r b a zid e
(15): mp 54.5-57.5 °C (petroleum ether-ethyl acetate); IR 3300,
1740, 1680, 1530, 1430, 1220 cm-1; H NMR δ 1.26 (t, 3H, J )
1
7.1 Hz), 2.37 (s, 3H), 4.22 (q, 2H, J ) 7.1 Hz), 6.94 (s, 1H), 7.04
(m, 1H), 7.24 (m, 5H), 7.37 (m, 4H); MS (FAB) m/z 314 (M+
+
H, 59), 194 (100); HRMS (FAB) calcd for C17H20N3O3 (M+ + H)
314.1505, found 314.1492. Anal. Calcd for C17H19N3O3: C, 65.16;
H, 6.11; N, 13.41. Found: C, 65.40; H, 6.11; N, 13.48.
1-Eth oxyca r bon yla m in o-6-flu or o-2(3H)-ben zim id a zolo-
n e (11e): mp 146-152 °C (ethyl acetate); IR 3260, 1740, 1710,
1680, 1490, 1260 cm-1; 1H NMR δ 1.26 (t, 3H, J ) 7.1 Hz), 4.15
(q, 2H, J ) 7.1 Hz), 6.85 (m, 2H), 6.99 (m, 1H), 10.20 (s, 1H),
11.07 (s, 1H); 13C NMR δ 14.3, 61.5, 95.4 (d, J ) 29.1 Hz), 107.9
(d, J ) 24.0 Hz), 110.0 (d, J ) 9.1 Hz), 122.6 (d, J ) 1.1 Hz),
130.9 (d, J ) 13.1 Hz), 153.1, 155.3, 157.9 (d, J ) 235.9 Hz); MS
1-(E t h oxyca r b on yl)-4-p h en yl-1-(4-t olyl)sem ica r b a zid e
(16): mp 152-153 °C (petroleum ether-ethyl acetate); IR 3380,
3280, 1700, 1670, 1530, 1340 cm-1; H NMR δ 1.18 (t, 3H, J )
1
7.2 Hz), 2.28 (s, 3H), 4.14 (q, 2H, J ) 7.2 Hz), 6.96 (m, 1H), 7.15
(m, 2H), 7.25 (m, 2H), 7.34 (m,2H), 7.45 (m, 2H), 8.90 (s, 1H),
8.92 (s, 1H); 13C NMR δ 14.3, 20.4, 61.9, 118.5, 122.0, 123.6,
128.6, 128.7, 134.6, 139.4, 140.2, 154.67, 154.74; MS (FAB) m/z
(EI) m/z 239 (M+, 86), 167 (100), 151 (47); HRMS calcd for C10H10
-

Notes
J . Org. Chem., Vol. 64, No. 7, 1999 2563
314 (M+ + H, 68), 195 (100), 194 (85), 178 (47), 121 (46). Anal.
Calcd for C17H19N3O3: C, 65.16; H, 6.11; N, 13.41. Found: C,
65.03; H, 6.19; N, 13.39.
support. We would like to thank Dr. Bogdan Kralj and
Dr. Dusˇan Zˇigon (Mass Spectrometry Center, J ozˇef
Stefan Institute, Ljubljana, Slovenia) for mass measure-
ments.
Ack n ow led gm en t. The Ministry of Science and
Technology of Slovenia and the Slovenian Science
Foundation are gratefully acknowledged for financial
J O9821170