Reactions of pyridine analogues of aza-ortho-xylylenes generated from 1,3-dialkylpyridosultams

Article abstract of DOI:10.1002/1099-0690(200004)2000:7<1263::AID-EJOC1263>3.0.CO;2-E

2,3-Dihydro-3-imino-2-methylenepyridines, generated by thermal extrusion of SO₂ from 1,3-dialkyl-1,3-dihydroisothiazolo[4,3-b]pyridine 2,2-dioxides (1,3-dialkylpyridosultams), underwent [1,5] hydrogen shifts, which led to 3- alkylamino-2-vinylpyridine derivatives. Cycloalkanespiro-3-pyridosultams 12, which were easily obtained by alkylation of pyridosultams with α,ω- dihaloalkanes, gave, in a similar reaction, 3-alkylamino-2- cycloalkenylpyridine derivatives 14 in good yields. Cyclobutanespiro-3- pyridosultam 12b, after thermal extrusion of SO₂, formed cyclobutenyl derivative 14b, which underwent a ring-opening reaction to form butadiene derivative 15. The latter can be trapped with dienophiles, for example, N- phenylmaleimide.

Full text of DOI:10.1002/1099-0690(200004)2000:7<1263::AID-EJOC1263>3.0.CO;2-E

FULL PAPER
Reactions of Pyridine Analogues of Aza-ortho-xylylenes Generated from
1,3-Dialkylpyridosultams
[a]
[a]
´
Szymon Kosinski and Krzysztof Wojciechowski*
Keywords: Alkenes / Nitrogen heterocycles / Pericyclic reactions / Rearrangements / Spiro compounds
2,3-Dihydro-3-imino-2-methylenepyridines, generated by
thermal extrusion of SO2 from 1,3-dialkyl-1,3-dihydroisothia-
3-alkylamino-2-cycloalkenylpyridine derivatives 14 in good
yields. Cyclobutanespiro-3-pyridosultam 12b, after thermal
zolo[4,3-b]pyridine 2,2-dioxides (1,3-dialkylpyridosultams), extrusion of SO2, formed cyclobutenyl derivative 14b, which
underwent [1,5] hydrogen shifts, which led to 3-alkylamino-
2-vinylpyridine derivatives. Cycloalkanespiro-3-pyridosul-
underwent a ring-opening reaction to form butadiene deriv-
ative 15. The latter can be trapped with dienophiles, for ex-
tams 12, which were easily obtained by alkylation of pyrido- ample, N-phenylmaleimide.
sultams with α,ω-dihaloalkanes, gave, in a similar reaction,
Introduction
Now we report on the results of our studies on the reac-
tions of aza-ortho-xylylene analogues generated from 3-al-
kyl derivatives of pyridosultams.
Aza-ortho-xylylenes (6-methylene-2,4-cyclohexadien-1-
imines) are potential building blocks for the construction
of condensed heterocyclic systems.[1] These reactive 1-azadi-
enes enter the Diels–Alder reaction leading to 1,2,3,4-tetra-
hydroquinoline derivatives. In recent years we have de-
veloped a method for the generation of aza-ortho-xylylenes
by thermal extrusion of SO2 from 1,2-benzisothiazoline 2,2-
dioxide derivatives[2] and applied it to the generation of
practically unknown pyridine analogues of aza-ortho-xylyl-
enes.[3] The only known methods of generation of hetero-
cyclic analogues of aza-ortho-xylylenes involve thermal 1,4-
elimination of water from 3-amino-2-(1-hydroxyalkyl)pyrid-
ine under flash vacuum thermolysis (FVT) conditions,[4]
thermal (FVT) 1,5-elimination of hydrogen chloride from
imidochloride derived from 4-amino-3-methylpyridine[5] or
base-induced 1,4-elimination of hydrogen fluoride from 3-
amino-4-(trifluoromethyl)quinoline.[6] In one of our previ-
ous papers we described the generation of pyridine ana-
logues of aza-ortho-xylylenes by thermal extrusion of SO2
from easily available 1,3-dihydroisothiazolo[4,3-b]pyridine
2,2-dioxides (pyridosultams)[3] and applied them to reac-
tions with various dienophiles. For example, the Diels–Al-
der reaction of N-phenylmaleimide (NPMI) with aza-ortho-
xylylene generated from N-methylpyridosultam at 215 °C
gave the corresponding tetrahydro[1,5]naphthyridine deriv-
ative in good yield.[3] Similarly, N-methyl-3-phenylpyridos-
ultam extruded SO2 in boiling toluene and formed aza-or-
tho-xylylene that reacted with 1,4-naphthoquinone to give
the corresponding Diels–Alder cycloaddition product.[7]
Aza-ortho-xylylene generated from N-(5-pent-1-enyl)pyri-
dosultam underwent an intramolecular Diels–Alder reac-
tion with its terminal double bond, to form 5,6,6a,7,8,9-
hexahydropyrrolo[1,2-a][1,5]naphthyridine.[3]
Pyridosultams are easily available from 3-amino-2-
chloropyridine (1) and alkanesulfonyl chlorides by the fol-
lowing sequence of reactions: bis-N-sulfonylation, desulfon-
ylation, N-alkylation and cyclization (Scheme 1). Since the
sulfonylation of 1 with one mol of methanesulfonyl chloride
led to an inseparable mixture of mono- and disulfonylated
products 2 and 3, we developed a procedure in which the
aminopyridine 1 was disulfonylated, after which one of the
sulfonyl groups was removed under basic conditions; this
gave the monosulfonylated product 3 in high yield. The
monosulfonamide was then N-alkylated with an alkyl hal-
ide in the presence of K2CO3 in dimethylformamide. Fi-
nally, the cyclization of the N-alkylsulfonamide 4 in the
presence of solid NaOH or tBuOK in DMSO gave pyrido-
sultam 5 in good yield.
Scheme 1
This procedure, starting with ethanesulfonyl chloride,
makes 1,3-dimethylpyridosultam 5b accessible, and can be
extended to other 3-alkyl-substituted derivatives, with the
corresponding commercially available alkanesulfonyl chlor-
ides as starting materials. In the synthesis of 1,3-dimethyl-
pyridosultam, the final cyclization should be carried out
[a]
Institute of Organic Chemistry, Polish Academy of Sciences
ul. Kasprzaka 44/52, 01–224 Warszawa 42, PO Box 58, Poland
E-mail: kris@icho.edu.pl
Eur. J. Org. Chem. 2000, 1263Ϫ1270
WILEY-VCH Verlag GmbH, D-69451 Weinheim, 2000
1434Ϫ193X/00/0407Ϫ1263 $ 17.50ϩ.50/0
1263

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S. Kosinski, K. Wojciechowski
FULL PAPER
under anaerobic conditions, since the anion of the formed pound was a result of [1,5] hydrogen shift in the interme-
sultam 5b is oxidised in the presence of air to pyridinyl- diate azaxylylene 7 (Scheme 3).
ethanone derivative 6. In an independent experiment, we
We carried out the alkylation of N-methylpyridosultam
found that 1,3-dimethylpyridosultam 5b is oxidised to 1-[3- in order to synthesize 3,3-dialkylpyridosultams. In most
(methylamino)-2-pyridyl]-ethanone (6) in 68% yield when cases, the alkylation was complete within 15 min in NaOH/
stirred with NaOH in DMSO for 2 h in air (Scheme 2). Au- DMSO at room temperature. Thus, when N-methylpyridos-
tooxidation of anions derived from benzosultams was used ultam 5a and methyl iodide were dissolved in DMSO and
previously for the synthesis of benzophenones[8] and 2H- stirred with finely powdered NaOH for 30 min at room tem-
isoindoles.[9]
perature, the expected 3,3-dimethyl derivative 9 was ob-
tained in 88% yield. The sultam 9, when refluxed in 1,2,4-
trichlorobenzene for 15 min, gave N-(2-isopropenyl-3-pyri-
dyl)-N-methylamine (11) in 90% yield (Scheme 4).
Scheme 2
The attempts to obtain 1,3-dialkylpyridosultams by
monoalkylation of the 1-alkylpyridosultam with alkyl hal-
ides were unsuccessful because of a subsequent alkylation
reaction of the desired product. For example, the reaction
of 1-methylpyridosultam 5a with one mol of methyl iodide
in various base–solvent systems (NaOH/DMSO, tBuOK/
DMF) led to a mixture of mono- and dialkylated products
and unchanged starting material. Therefore, the procedure
described above employing alkanesulfonyl chlorides, as ex-
emplified by the reaction with ethanesulfonyl chloride,
seems to be more convenient for this purpose.
Attempts to introduce aza-ortho-xylylene 7 derived from
the pyridosultam 5b in the Diels–Alder reaction with NPMI
were unsuccessful. After both reagents were heated in boil-
ing 1,2,4-trichlorobenzene (TCB, 215 °C), a complex mix-
ture was formed in which the cycloaddition product was
not detected. GC-MS analysis revealed the presence of a
product whose molecular mass corresponded to the loss of
sulfur dioxide [M – 64] from the starting compound 5b.
When this reaction was performed in the absence of a dien-
ophile, the product was isolated and identified as N-methyl-
N-(2-vinyl-3-pyridyl)amine (8). The formation of this com-
Scheme 4
Alkylation of N-methylpyridosultam with homologous
C2–C6 α,ω-dihaloalkanes gave the corresponding cycloalk-
anospiro-3-pyridosultams 12 in good yields (Scheme 5).
It is noteworthy that the ambident carbanions formed in
these reactions are not N-alkylated, but only C3-alkylated.
It was proved by the NMR spectra of the obtained prod-
ucts. For example, alkylation of the pyridosultam 5a with
1,5-dibromopentane gave the spirocyclohexano compound
12d. In the 13C NMR spectrum of this product, there were
only four signals in the aliphatic region. The alternative
compound 13d, if formed, would have exhibited five signals
in the same region of the 13C NMR spectrum.
The thermal extrusion of SO2 from cycloalkanospiropyri-
dosultams 12c–12e in boiling trichlorobenzene was com-
pleted in 15 min and gave the corresponding 2-cycloalkenyl-
pyridine derivatives 14c–14e in very good yields. Only in the
case of cyclopropanospiropyridosultam 12a did no extru-
sion occur, and after prolonged heating at 215 °C, this com-
pound remained unchanged. The experiments in a pyrolytic
oven attached to the GC-MS system revealed that this com-
pound extruded SO2 at 500–650 °C; a mixture of products
resulted and, for the main product, the structure of 1,3-
dimethyl-1H-pyrrolo[3,2-b]pyridine (17a) was assigned.
This was supported by the results of an analogous reaction
of cyclopropanospirobenzosultam 16 in which the main
product was identified as 1,3-dimethylindole (17b). These
compounds were possibly formed as shown in Scheme 6.
After the extrusion of SO2, a [1,5] sigmatropic shift oc-
curred, followed by a well precedented isomerization of
cyclopropene to vinylcarbene,[10,11] which inserted into the
Scheme 3
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Eur. J. Org. Chem. 2000, 1263Ϫ1270

Reactions of Pyridine Analogues
FULL PAPER
Scheme 5
Scheme 6
N–H bond. Finally, an isomerization of the exocyclic enyl)-3-pyridyl]-N-methylamine 19, resulting from [1,5] hy-
double bond led to the observed compounds 17a,b. drogen shift in the intermediate azaxylylene 18, underwent
In the case of cyclobutanospiropyridosultam 12b, the ex- electrocyclic opening of the cyclobutene ring, giving, finally,
trusion of SO2 proceeded very easily and N-[2-(1-cyclobut- N-methyl-N-[2-(1-methyleneallyl)-3-pyridyl]amine (15).
Eur. J. Org. Chem. 2000, 1263Ϫ1270
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S. Kosinski, K. Wojciechowski
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Scheme 7
When the thermal extrusion of SO2 from the sultam 12b
was performed in the presence of N-phenylmaleimide, a
[4ϩ2] cycloaddition to the formed butadiene 15 occurred
and the N-[2-(1-cyclohexenyl)-3-pyridyl]-N-methylamine
20 was formed (Scheme 7). The addition of the butadiene
15 to dimethyl fumarate, leading to diester 21, proceeded
similarly. In the reaction of 15 with phenyl vinyl sulfone, an
inseparable mixture of two isomeric phenylsulfonylcy-
clohexene derivatives 22a,b was formed.
Alkylation of N-methylpyridosultam 5a with 1,2-bis(bro-
momethyl)benzene (23) under standard conditions (NaOH,
DMSO, room temp, 1 h) gave a mixture of the expected
alkylation product 24 and N-[2-(1H-inden-2-yl)-3-pyridyl]-
N-methylamine (25). The latter was formed as a result of
base-induced elimination of SO2 from the spiroindane de-
rivative 24. However, when the alkylation was carried out
for 5 min, the expected spiroindane derivative 24 was
formed in 81% yield. In boiling TCB it gave the correspond-
ing aza-ortho-xylylene 26, which, after [1,5] hydrogen shift,
formed the indene derivative 25 in high yield (Scheme 8).
The described reactions gave easy access to substituted
3-amino-2-vinylpyridine derivatives which may be used for
the synthesis of azaindole derivatives,[12] analogously to the
Scheme 8
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Reactions of Pyridine Analogues
FULL PAPER
with ethyl acetate and dried with MgSO4. After evaporation of the
solvent, the crude product was used in the next step without further
purification. The following compounds were obtained:
synthesis of indoles by ring closure of 2-vinylaniline derivat-
ives.[13,14]
N-(2-Chloro-3-pyridyl)-N-methylmethanesulfonamide (4a): Yield:
quantitative, m.p. 93–95 °C (from EtOH). – H NMR (200 MHz,
1
Experimental Section
CDCl3): δ ϭ 3.04 (s, 3 H), 3.29 (s, 3 H), 7.32 (dd, J ϭ 7.8 Hz, J ϭ
4.7 Hz, 1 H), 7.82 (dd, J ϭ 7.9 Hz, J ϭ 1.8 Hz, 1 H), 8.35 (dd,
J ϭ 4.7 Hz, J ϭ 1.8 Hz, 1 H). – 13C NMR (CDCl3): δ ϭ 38.1,
40.3, 124.0, 135.7, 141.9, 149.7, 150.7. – MS (70 eV); m/z (%): 222
(24) [M ϩ 2ϩ], 220 [Mϩ] (65), 185 (67), 143 (34), 142 (29), 141
(100), 128 (19), 126 (42), 105 (52), 100 (17), 78 (82). – HRMS
(C7H9ClN2O2S): calcd. 220.0073; found 220.0057. – C7H9ClN2O2S
(220.7): calcd. C 38.10, H 4.11, N 12.69, S 14.53; found C 38.08,
H 4.29, N 12.69, S 14.32.
1
Melting points are uncorrected. – H NMR spectra were obtained
with Bruker AMX (500 MHz) and Varian Gemini (200 MHz) in-
struments with TMS as internal standard. Coupling constants are
given in Hz. – Mass spectra (electron impact, 70 eV) were obtained
on an AMD 604 (AMD Intectra GmbH, Germany) instrument.
HRMS were measured in the presence of perfluorokerosene as the
reference compound. – Column chromatography was performed
with silica gel 240–400 mesh (Merck). – All starting materials and
solvents were commercial and were used without purification.
N-(2-Chloro-3-pyridyl)-N-methylethanesulfonamide (4b): Yield: 84%
(oil). – 1H NMR (200 MHz, CDCl3): δ ϭ 1.49 (t, J ϭ 7.4 Hz, 3
H), 3.21 (q, J ϭ 7.4 Hz, 2 H), 3.36 (s, 3H), 7.32 (dd, J ϭ 7.9 Hz,
J ϭ 4.7 Hz, 1 H), 7.89 (dd, J ϭ 7.9 Hz, J ϭ 1.9 Hz, 1 H), 8.32 (dd,
J ϭ 4.7 Hz, J ϭ 1.9 Hz, 1 H). – 13C NMR (CDCl3): δ ϭ 8.6, 38.7,
48.2, 124.0, 136.0, 142.0, 149.6, 150.7. – MS (70 eV); m/z (%): 236
(17) [M ϩ 2ϩ], 234 (45) [Mϩ], 199 (39), 143 (34), 142 (48), 141
General Procedure for the Synthesis of N-(2-Chloro-3-pyridyl)alk-
anesulfonamides 3: To a solution of 3-amino-2-chloropyridine (1,
10.3 g, 0.08 mol) and triethylamine (18.0 g, 0.18 mol) dissolved in
dichloromethane (80 mL) and cooled to 5 °C, the solution of al-
kanesulfonyl chloride (0.18 mol) in dichloromethane (40 mL) was
added dropwise, with stirring; the temperature was kept below 10
°C. After the addition, the reaction mixture was stirred for 2 h at
room temperature, and was then evaporated to dryness under re-
duced pressure. Aqueous NaOH (10%, 320 mL, 0.8 mol) was added
to the residue, and the mixture was stirred for 30 min to complete
dissolution. Then the solution was neutralized with aqueous HCl
to pH ϭ 7, was saturated with Na2SO4, and extracted several times
with ethyl acetate. The extracts were combined, dried (MgSO4),
and evaporated. The product was purified by crystallization from
hexane/ethyl acetate and some of the product was isolated by col-
umn chromatography of the filtrate. The following compounds
were obtained:
(100), 126 (29), 105 (54), 78 (65), 39 (23).
– HRMS
(C8H1135ClN2O2S): calcd. 234.0230; found 234.0230.
General Procedure for the Synthesis of Pyridosultams 5: Potassium
tert-butoxide (2.24 g, 20 mmol) was added to a stirred solution of
N-(2-chloropyridine)-N-methylalkanesulfonamide 4 (7 mmol) in
DMSO (20 mL). The reaction mixture was stirred for 40 min at
room temp, was then poured into the solution of NH4Cl, and was
saturated with solid Na2SO4. The product was extracted with ethyl
acetate and dried with MgSO4. After evaporation of the solvent,
the product was purified by column chromatography. The following
compounds were obtained:
N-(2-Chloro-3-pyridyl)methanesulfonamide (3a): Yield: 14.9 g, 72
1
1-Methyl-1,3-dihydroisothiazolo[4,3-b]pyridine 2,2-Dioxide (N-
Methylpyridosultam) (5a): Yield: 63%, m.p. 148–150 °C (hexane/
ethyl acetate). – 1H NMR (200 MHz, CDCl3): δ ϭ 3.15 (s, 3 H),
4.46 (s, 2 H), 6.98 (dd, J ϭ 8.1 Hz, J ϭ 1.3 Hz, 1 H), 7.26 (dd, J ϭ
8.1 Hz, J ϭ 5.1 Hz, 1 H), 8.18 (dd, J ϭ 5.1 Hz, J ϭ 1.3 Hz, 1
H). – 13C NMR (CDCl3): δ ϭ 26.7, 52.6, 115.9, 124.7, 138.6, 140.3,
143.0. – MS (70 eV); m/z (%): 184 (58) [Mϩ], 120 (24), 119 (100),
105 (18), 92 (8), 79 (14). – HRMS (C7H8N2O2S): calcd. 184.0307;
found 184.0322. – C7H8N2O2S (184.2): calcd. C 45.65, H 4.35, N
15.22; found C 45.65, H 4.36, N 15.14.
mmol (90%), m.p. 94–95 °C (from EtOH). – H NMR (200 MHz,
CDCl3): δ ϭ 3.09 (s, 3 H), 7.20 (broad s, 1 H), 7.32 (dd, J ϭ 8.1 Hz,
J ϭ 4.7 Hz, 1 H), 8.00 (dd, J ϭ 8.1 Hz, J ϭ 1.8 Hz, 1 H), 8.24 (dd,
J ϭ 4.7 Hz, J ϭ 1.8 Hz, 1 H). – 13C NMR (CDCl3): δ ϭ 41.1,
124.2, 131.2, 131.5, 142.9, 146.2. – MS (70 eV); m/z (%): 208 (22)
[M ϩ 2ϩ], 206 (62) [Mϩ], 129 (35), 128 (65), 127 (100), 100 (39),
92 (38), 65 (12), 39 (30). – HRMS (C6H735ClNSO2): calcd.
205.9917; found 205.9926. – C6H7ClN2O2S (206.7): calcd. C 34.87,
H 3.41, N 13.56; found C 34.85, H 3.78, N 13.37. – Also 0.41 g
(4%) of 3-amino-2-chloropyridine was regenerated.
1,3-Dimethyl-1,3-dihydroisothiazolo[4,3-b]pyridine 2,2-Dioxide (1,3-
Dimethylpyridosultam) (5b): The reaction was carried out under ar-
gon. Yield: 70%; m.p. 75–76 °C (from EtOH). – 1H NMR
(200 MHz, CDCl3): δ ϭ 1.80 (d, J ϭ 7.1 Hz, 3 H), 3.18 (s, 3 H),
4.39 (q, J ϭ 7.1 Hz, 1 H), 7.00 (dd, J ϭ 8.1 Hz, J ϭ 1.3 Hz, 1 H),
7.27 (dd, J ϭ 8.1 Hz, J ϭ 5.0 Hz, 1 H), 8.21 (dd, J ϭ 5.0 Hz, J ϭ
1.3 Hz, 1 H). – 13C NMR (CDCl3): δ ϭ 12.2, 26.7, 57.4, 115.9,
124.6, 137.7, 143.1, 144.9. – MS (70 eV); m/z (%): 198 (37) [Mϩ],
134 (47), 133 (90), 119 (100), 106 (11), 92 (16), 66 (11), 39 (22). –
N-(2-Chloro-3-pyridyl)ethanesulfonamide (3b): Yield: 12.0 g, 54
mmol (68%), m.p. 70–72 °C (from EtOH). – H NMR (200 MHz,
1
CDCl3): δ ϭ 1.43 (t, J ϭ 7.4 Hz, 3 H), 3.18 (q, J ϭ 7.4 Hz, 2 H),
7.00 (broad s, 1H), 7.31 (dd, J ϭ 8.1 Hz, J ϭ 4.8 Hz, 1 H), 8.04
(dd, J ϭ 8.1 Hz, J ϭ 1.7 Hz, 1 H), 8.22 (dd, J ϭ 4.8 Hz, J ϭ
1.7 Hz, 1 H). – 13C NMR (CDCl3): δ ϭ 8.7, 47.8, 124.1, 129.8,
131.8, 142.0, 145.9. – MS (70 eV); m/z (%): 222 (12) [M ϩ 2ϩ], 220
(33) [Mϩ], 130 (32), 128 (100), 127 (30), 100 (12), 92 (50), 65 (21),
39 (26). – HRMS (C7H935ClN2O2S): calcd. 220.0073; found
220.0077. – C7H9ClN2O2S (220.7): calcd. C 38.10, H 4.11, N 12.69,
S 14.53; found C 38.25, H 4.28, N 12.60, S 14.68.
HRMS (C8H10N2O2S): calcd. 198.0463; found 198.0461.
–
C8H10N2O2S (198.2): calcd. C 48.47, H 5.08, N 14.13; found C
48.44, H 4.95, N 14.24, S 16.00.
General Procedure for N-Methylation of Sulfonamides: The solution
of N-(2-chloro-3-pyridyl)alkanesulfonamide 3 (0.01 mol), methyl
iodide (2.13 g, 0.015 mol), and tetrabutylammonium bromide
The Reaction of 1,3-Dimethylpyridosultam (5) with NaOH/DMSO
in Air: 1,3-Dimethylpyridosultam (5b, 0.50 g, 2.5 mmol) was stirred
(0.32 g, 0.001 mol) in DMF (20 mL) was stirred with K2CO3 (10 g) with NaOH (1 g) in DMSO (5 mL) at 20 °C until the substrate
at room temp. The progress of the reaction was monitored by TLC.
When the starting sulfonamide disappeared, the reaction mixture
was poured into a solution of Na2SO4. The product was extracted
disappeared (2 h). The reaction mixture was then poured into an
aqueous solution of NH4Cl and was extracted with ethyl acetate.
After purification by column chromatography (hexane/ethyl acet-
Eur. J. Org. Chem. 2000, 1263Ϫ1270
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S. Kosinski, K. Wojciechowski
FULL PAPER
ate), 1-[3-(methylamino)-2-pyridyl]ethanone (6) was obtained.
Yield 0.23g (68%), yellow crystals, m.p. 83–86 °C (hexane/ethyl
(45), 133 (16), 132 (13), 131 (34). – HRMS (C11H14N2O2S): calcd.
238.0776 found: 238.0784. – C11H14N2O2S (238.3): calcd. C 55.44,
acetate). – 1H NMR (200 MHz, CDCl3): δ ϭ 2.73 (s, 3 H), 2.93 (d, H 5.92, N 11.76; found C 55.35, H 6.05, N 11.64.
J ϭ 5.1 Hz, 3 H), 7.07 (dd, J ϭ 8.7 Hz, J ϭ 1.2 Hz, 1 H), 7.31
Cyclohexanospiro-3Ј-(1Ј-methyl-1Ј,3Ј-dihydroisothiazolo[4,3-b]-
(dd, J ϭ 8.8 Hz, J ϭ 4.2 Hz, 1 H), 7.96 (dd, J ϭ 4.2 Hz, J ϭ 1.2
pyridine) 2Ј,2Ј-Dioxide (12d): Yield: 76%; m.p. 105–107 °C (hexane/
Hz, 1 H), 8.56 (broad s, 1 H). – 13C NMR (CDCl3): δ ϭ 27.6, 29.4,
ethyl acetate). – 1H NMR (200 MHz, CDCl3): δ ϭ 1.40–1.63 (m, 1
119.3, 129.1, 134.6, 136.0, 148.5, 204.5. – MS (70 eV); m/z (%): 150
H), 1.74–2.00 (m, 5 H), 2.02–2.20 (m, 2H), 2.24–2.40 (m, 2 H), 3.17
(100) [Mϩ], 149 (39), 135 (49), 133 (19), 107 (62), 93 (17), 79 (52). –
(s, 3 H), 6.97 (dd, J ϭ 8.0 Hz, J ϭ 1.4 Hz, 1 H), 7.23 (dd, J ϭ
HRMS (C8H10N2O): calcd. 150.0793; found 150.0794.
–
8.0 Hz, J ϭ 5.0 Hz, 1 H), 8.20 (dd, J ϭ 5.0 Hz, J ϭ 1.4 Hz, 1 H). –
13C NMR(CDCl3): δ ϭ 22.7, 25.2, 26.7, 31.2, 65.5, 115.9, 124.1,
136.4, 142.7, 149.1. – MS (70 eV); m/z (%): 252 (21) [Mϩ], 197 (12),
188 (19), 187 (43), 173 (15), 160 (29), 159 (100), 146 (21), 145 (41),
133 (10), 131 (14). – HRMS (C12H16N2O2S): calcd. 252.0933; found
252.0921. – C12H16N2O2S (252.3): calcd. C 57.12, H 6.39, N 11.10,
S 12.71; found C 56.93, H 6.50, N 11.04, S 12.93.
C8H10N2O (150.2): calcd. C 63.98, H 6.71, N 18.65; found C 63.52,
H 7.04, N 18.30. – IR (KBr): ν ϭ 3343 (s, N–H), 1651 (vs, CϭO).
General Procedure for Alkylation of N-Methylpyridosultam (5a): To
a solution of N-methylpyridosultam (5a, 1 mmol) and methyl iod-
ide (0.30 g, 2.1 mmol) or the corresponding α,ω-dialkyl halide
(1.1 mmol) in DMSO (20 mL), finely ground NaOH (0.80 g,
20 mmol) was added. The reaction was stirred for 30 min, then it
was poured into the solution of NH4Cl, and then this mixture was
saturated with Na2SO4. The product was extracted with ethyl acet-
ate and dried. After evaporation of the solvent, the product was
purified by column chromatography. The following compounds
were obtained:
Cycloheptanospiro-3Ј-(1Ј-methyl-1Ј,3Ј-dihydroisothiazolo[4,3-b]-
pyridine) 2Ј,2Ј-Dioxide (12e): Yield: 42%; m.p. 107–108 °C (hexane/
ethyl acetate). – 1H NMR (200 MHz, CDCl3): δ ϭ 1.60–2.10 (m, 8
H), 2.13–2.30 (m, 2 H), 2.45–2.60 (m, 2 H), 3.15 (s, 3 H), 6.98 (dd,
J ϭ 8.0 Hz, J ϭ 1.3 Hz, 1 H), 7.23 (dd, J ϭ 8.0 Hz, J ϭ 5.0 Hz, 1
H), 8.20 (dd, J ϭ 5.0 Hz, J ϭ 1.3 Hz, 1 H). – 13C NMR (CDCl3):
δ ϭ 23.9, 26.7, 31.3, 33.5, 68.5, 116.0, 124.0, 136.0, 142.7, 150.6. –
MS (70 eV); m/z (%): 266 (19) [Mϩ], 202(13), 201(15), 197(12),
187(19), 173(32), 160(20), 159(100), 146(41), 145(29), 133(15),
1,3,3-Trimethyl-1,3-dihydroisothiazolo[4,3-b]pyridine 2,2-Dioxide;
(1,3,3-Trimethyl)pyridosultam (9): Yield: 88%; m.p. 95–97 °C (ethyl
acetate). – 1H NMR (200 MHz, CDCl3): 1.74 (s, 6 H), 3.16 (s, 3
H), 7.00 (dd, J ϭ 8.1 Hz, J ϭ 1.3 Hz, 1 H), 7.24 (dd, J ϭ 8.1 Hz,
J ϭ 5.0 Hz, 1 H), 8.20 (dd, J ϭ 5.0 Hz, J ϭ 1.3 Hz, 1 H). – 13C
NMR(CDCl3): 21.6, 26.7, 61.6, 116.1, 124.4, 136.4, 143.0, 149.3. –
MS (70 eV); m/z (%): 212 (29) [Mϩ], 148 (20), 147 (44), 133 (100),
131(18).
– HRMS (C13H18N2O2S): calcd. 266.1089; found
266.1087. – C13H18N2O2S (266.4): calcd. C 58.62, H 6.81, N 10.52,
S 12.04; found C 58.46, H 6.95, N 10.38, S 12.2.
Indano-2-spiro-3Ј-(1Ј-methyl-1Ј,3Ј-dihydroisothiazolo[4,3-b]pyridine)
2Ј,2Ј-Dioxide (24): Reaction time: 5 min. Yield: 81%; m.p. 185–186
°C (ethyl acetate). – 1H NMR (200 MHz, CDCl3): δ ϭ 3.20 (s, 3
H), 3.61 (d, J ϭ 17.1 Hz, 2 H), 4.02 (d, J ϭ 17.1 Hz, 2 H), 7.03
(dd, J ϭ 8.0 Hz, J ϭ 1.4 Hz, 1 H), 7.27 (dd, J ϭ 8.0 Hz, J ϭ
5.0 Hz, 1 H), 7.26–7.30 (m, 4 H), 8.21 (dd, J ϭ 5.0 Hz, J ϭ 1.4 Hz,
1 H). – 13C NMR(CDCl3): δ ϭ 27.0, 40.7, 71.6, 116.0, 124.6, 124.9,
128.1, 137.0, 139.5, 143.3, 147.9. – MS (70 eV); m/z (%): 286 (10)
[Mϩ], 222 (55), 221 (100), 207 (26), 206 (14), 205 (12). – HRMS
(C15H14N2O2S): calcd. 286.0776; found 286.0759. – C15H14N2O2S
(286.4): calcd. C 62.92, H 4.93, N 9.78, S 11.12; found C 62.82, H
4.94, N 9.62, S 11.30.
39 (16).
– HRMS (C9H12N2O2S): calcd. 212.0620; found
212.0620. – C9H12N2O2S (212.3): calcd. C 50.93, H 5.70, N 13.20,
S 15.10; found C 50.95, H 5.70, N 13.14, S 15.12.
Cyclopropanospiro-3Ј-(1Ј-methyl-1Ј,3Ј-dihydroisothiazolo[4,3-b]pyri-
dine) 2Ј,2Ј-Dioxide (12a): Yield: 92%; m.p. 110–112 °C. – 1H NMR
(200 MHz, CDCl3): δ ϭ 1.81–1.85 (m, 2 H), 2.01–2.04 (m, 2 H),
3.22 (s, 3 H), 6.94 (dd, J ϭ 8.0 Hz, J ϭ 1.3 Hz, 1 H), 7.16 (dd, J ϭ
8.0 Hz, J ϭ 5.0 Hz, 1 H), 8.07 (dd, J ϭ 5.0 Hz, J ϭ 1.3 Hz, 1 H). –
13C NMR (CDCl3) δ ϭ 16.7, 27.3, 43.1, 114.8, 123.5, 137.5, 142.6,
144.4. – MS (70 eV); m/z (%): 210 (77) [Mϩ], 162(7), 144(5),
145(100), 131(32), 119(33), 118(29), 117(22), 104(17). – HRMS
(C9H10N2O2S): calcd. 210.0463; found 210.0458. – C9H10N2O2S
(210.3): calcd. C 51.41, H 4.79, N 13.32, S 15.25; found C 51.32,
H 4.73, N 13.34, S 15.35.
General Procedure for the Thermal Extrusion of SO2 from Pyrido-
sultams: Pyridosultam (1 mmol) was refluxed in trichlorobenzene
(10 mL) for 15 min. The reaction mixture was then subjected to
column chromatography. Trichlorobenzene was eluted with hexane/
ethyl acetate (10:1) and then the product with hexane/ethyl acetate
(1:1). The following compounds were obtained:
Cyclobutanospiro-3Ј-(1Ј-methyl-1Ј,3Ј-dihydroisothiazolo[4,3-b]pyri-
dine) 2Ј,2Ј-Dioxide (12b): Yield: 88%, m.p. 90–91 °C (hexane/ethyl
acetate). – H NMR (500 MHz, CDCl3): δ ϭ 2.20–2.29 (m, 1 H),
1
2.30–2.39 (m, 1 H), 2.66–2.73 (m, 2 H), 3.01–3.9 (m, 2 H), 3.13 (s,
3 H), 6.91 (dd, J ϭ 8.0 Hz, J ϭ 1.2 Hz, 1 H), 7.21 (dd, J ϭ 8.0 Hz,
J ϭ 5.0 Hz, 1 H), 8.23 (dd, J ϭ 5.0 Hz, J ϭ 1.3 Hz, 1 H). – 13C
NMR (CDCl3): δ ϭ 15.8, 27.0, 29.4, 63.7, 115.5, 124.5, 136.7,
143.2, 147.4. – MS (70 V) m/z (%): 224 (75) [Mϩ], 196 (100), 159
(67), 145 (42), 132 (74), 131 (67). – HRMS (C10H12N2O2S): calcd.
224.0620; found 224.0620. – C10H12N2O2S (224.3): calcd. C 53.55,
H 5.39, N 12.49, S 14.29; found C 53.40, H 5.41, N 12.33, S 14.05.
N-Methyl-N-(2-vinyl-3-pyridyl)amine (8): Yield: 83% (oil). – 1H
NMR (CDCl3): δ ϭ 2.89 (s, 3 H), 5.54 (dd, J ϭ 11.0 Hz, J ϭ
2.0 Hz, 1 H), 6.20 (dd, J ϭ 17.2 Hz, J ϭ 2.0 Hz, 1 H), 6.87 (dd,
J ϭ 17.2 Hz, J ϭ 11.0 Hz, 1 H), 6.94 (dd, J ϭ 8.2 Hz, J ϭ 1.4 Hz,
1 H), 7.13 (dd, J ϭ 8.2 Hz, J ϭ 4.6 Hz, 1 H), 8.02 (dd, J ϭ 4.6 Hz,
J ϭ 1.4 Hz, 1 H). – 13C NMR(CDCl3): δ ϭ 30.9, 117.5, 119.6,
132.9, 131.9, 138.3, 142.2, 143.0. – MS (70 eV); m/z (%): 134 (79)
[Mϩ], 133 (39), 119 (100), 106 (9), 92 (24), 79 (11), 65 (15), 39
(24). – HRMS (C8H10N2): calcd. 134.0844; found 134.0843.
Cyclopentanospiro-3Ј-(1Ј-methyl-1Ј,3Ј-dihydroisothiazolo[4,3-b]-
pyridine) 2Ј,2Ј-Dioxide (12c): Yield: 88%; m.p. 56–57 °C (hexane/
ethyl acetate). – 1H NMR (200 MHz, CDCl3): δ ϭ 1.9–2.1 (m, 4 N-(2-Isopropenyl-3-pyridyl)-N-methylamine (11): Yield: 90% (oil). –
H), 2.1–2.3 (m, 2 H), 2.6–2.8 (m, 2 H), 6.94 (dd, J ϭ 8.1 Hz, J ϭ 1H NMR (200 MHz, CDCl3): δ ϭ 2.16 (dd, J ϭ 1.2 Hz, J ϭ
1.3 Hz, 1 H), 7.19 (dd, J ϭ 8.1 Hz, J ϭ 5.0 Hz, 1 H), 8.17 (dd, J ϭ
1.4 Hz, 3 H), 2.82 (d, J ϭ 5.1 Hz, 3 H), 4.4 (broad s, 1 H), 5.26
5.0 Hz, J ϭ 1.3 Hz, 1 H). – 13C NMR(CDCl3): δ ϭ 26.5, 26.9, 35.0, (dq, J ϭ 1.8 Hz, J ϭ 1.2 Hz, 1 H), 5.46 (dq, J ϭ 1.8 Hz, J ϭ
72.0, 115.7, 124.1, 136.9, 143.0, 149.1. – MS (70 eV); m/z (%): 238
1.4 Hz, 1 H), 6.88 (dd, J ϭ 8.3 Hz, J ϭ 1.4 Hz, 1 H), 7.07 (dd, J ϭ
8.3 Hz, J ϭ 4.6 Hz, 1 H), 7.95 (dd, J ϭ 4.6 Hz, J ϭ 1.4 Hz, 1 H) –
(35) [Mϩ], 197 (23), 174 (27), 173 (46), 159 (18), 146 (100), 145
1268
Eur. J. Org. Chem. 2000, 1263Ϫ1270

Reactions of Pyridine Analogues
FULL PAPER
13C NMR(CDCl3): δ ϭ 23.4, 30.9, 116.3, 116.6, 123.2, 137.1, 142.4, tam (17, 0.4 mmol) and a dienophile (0.7 mmol) were refluxed in
143.5, 147.3. – MS (70 eV); m/z (%): 148 (65) [Mϩ], 147 (51), 133 trichlorobenzene (5 mL) for 30 min. The reaction mixture was
(100), 132 (14), 118 (14), 39 (11). – HRMS (C9H12N2): calcd. passed through a chromatography column. Trichlorobenzene was
148.1001; found 148.1021.
eluted with hexane/ethyl acetate (10:1) and then the product was
eluted with hexane/ethyl acetate (1:1). The following compounds
were obtained:
N-Methyl-N-[2-(1-methyleneallyl)-3-pyridyl]amine (15): Yield: 60%
(oil). – 1H NMR (200 MHz, CDCl3): 2.84 (d, J ϭ 3.6 Hz, 3 H),
4.02 (broad s, 1 H), 4.96 (br. d, J ϭ 17.4 Hz, 1 H), 5.20 (br. d, J ϭ
10.5 Hz, 1 H), 5.38–5.40 (m, 1 H), 5.61–5.63 (m, 1 H), 6.63 (dd,
J ϭ 17.4 Hz, J ϭ 10.5 Hz, 1 H), 6.95 (dd, J ϭ 8.2 Hz, J ϭ 1.3 Hz,
1 H), 7.17 (dd, J ϭ 8.2 Hz, J ϭ 4.7 Hz, 1 H), 7.53 (dd, J ϭ 4.7 Hz,
J ϭ 1.3 Hz, 1 H). – 13C NMR (CDCl3): 30.1, 115.9, 117.3, 120.0,
123.1, 136.3, 137.1, 142.6, 144.0, 145.1. – MS (70 eV); m/z (%): 160
(69) [Mϩ], 159 (76), 146 (11), 145 (100), 144 (35), 143 (18), 132
(15), 131 (30), 130 (82), 118 (23), 117 (29), 79 (14), 78 (12), 77 (12),
66 (11), 39 (17). – HRMS (C10H12N2): calcd. 160.1001; found
160.0998.
From N-Phenylmaleimide: 5-[3-(Methylamino)-2-pyridyl]-2-phenyl-
3a,4,7,7a-tetrahydro-1H-isoindole 1,3(2H)-Dioxide (20): Yield: 81%,
m.p. 151–152 °C (ethyl acetate). – 1H NMR (200 MHz, CDCl3):
δ ϭ 2.53 (dddd, J ϭ 15.9 Hz, J ϭ 6.5 Hz, J ϭ 3.8 Hz, J ϭ 2.3 Hz,
1 H), 2.72 (d, J ϭ 4.9 Hz, 3 H), 2.78 (dddd, J ϭ 15.7 Hz, J ϭ
7.4 Hz, J ϭ 2.3 Hz, J ϭ 2.3 Hz, 1 H), 2.88 (ddd, J ϭ 15.9, J ϭ
6.5 Hz, J ϭ 3.1 Hz, 1 H), 3.14 (dd, J ϭ 15.7 Hz, J ϭ 3.1 Hz, 1 H),
3.35 (ddd, J ϭ 9.3 Hz, J ϭ 7.4 Hz, J ϭ 3.1 Hz, 1 H), 3.43 (ddd,
J ϭ 9.3 Hz, J ϭ 6.5 Hz, J ϭ 3.1 Hz, 1 H), 4.20 (q, J ϭ 4.9 Hz, 1
H), 6.34 (ddd, J ϭ 6.5 Hz, J ϭ 3.8 Hz, J ϭ 2.3 Hz, 1 H), 6.86 (dd,
J ϭ 8.2 Hz, J ϭ 1.3 Hz, 1 H), 7.05 (dd, J ϭ 8.2 Hz, J ϭ 4.6 Hz, 1
H), 7.24–7.27 (m, 2 H), 7.34–7.38 (m, 1 H), 7.42–7.46 (m, 2 H),
7.95 (dd, J ϭ 4.6 Hz, J ϭ 1.4 Hz, 1 H). – 13C NMR(CDCl3): δ ϭ
25.3, 28.0, 30.8, 39.7, 40.5, 117.1, 123.6, 126.8, 127.6, 129.1, 129.6,
132.5, 137.7, 138.7, 142.6, 144.9, 179.5. – MS (70 eV); m/z (%): 333
(81) [Mϩ], 332 (30), 318 (10), 186 (23), 185 (68), 171 (14), 169 (21),
160 (19), 159 (50), 146 (100), 145 (46) 131 (12). – HRMS
(C20H19N3O2): calcd. 333.1477; found 333.1452.
N-[2-(1-Cyclopentenyl)-3-pyridyl]-N-methylamine (14c): Yield: 86%,
m.p. 103–104 °C (ethyl acetate). – 1H NMR (200 MHz, CDCl3):
δ ϭ 2.04–1.88 (m, 2 H), 2.66–2.53 (m, 2 H), 2.91–2.78 (m, 5 H),
4.44 (broad s, 1 H), 6.20–6.15 (m; 5 lines, 1 H), 6.86 (dd, J ϭ
8.2 Hz, J ϭ 1.5 Hz, 1 H), 7.01 (dd, J ϭ 8.2 Hz, J ϭ 4.6 Hz, 1 H),
7.94 (dd, J ϭ 4.6 Hz, J ϭ 1.5 Hz, 1 H). – 13C NMR (CDCl3): δ ϭ
23.3, 31.0, 34.8, 36.4, 116.5, 122.8, 130.6, 137.4, 142.8, 143.3,
143.6. – MS (70 eV); m/z (%): 174 (100) [Mϩ], 173 (52), 159 (21),
158 (14), 146 (70), 145 (50), 132 (15), 131 (42), 66 (10). – HRMS
(C11H14N2): calcd. 174.1157; found 174.1152. – C11H14N2 (174.3):
calcd. C 75.82, H 8.10, N 16.08; found C 75.50, H 8.02, N 15.99.
From Dimethyl Fumarate: Dimethyl trans-4-[3-(Methylamino)-2-py-
ridyl]-4-cyclohexene-1,2-dicarboxylate (21): Yield: 91%; m.p. 102.5–
103.5 °C (ethyl acetate/hexane 1:1). – 1H NMR (200 MHz, CDCl3):
δ ϭ 2.40–2.48 (m, 1 H), 2.52– 2.64 (m, 2 H), 2.80–2.87 (m, 4 H),
3.03 (ddd, J ϭ 10.0 Hz, J ϭ 10.0 Hz, J ϭ 5.8 Hz, 1 H), 3.12 (ddd,
J ϭ 10.0 Hz, J ϭ 10.0 Hz, J ϭ 5.5 Hz, 1 H), 3.70 (s, 3 H), 3.73 (s,
3 H), 4.35 (broad s, 1 H), 5.97–6.00 (m, 1 H), 6.87 (dd, J ϭ 8.2 Hz,
J ϭ 1.1 Hz, 1 H), 7.06 (dd, J ϭ 8.2 Hz, J ϭ 4.7 Hz, 1 H), 7.91 (dd,
J ϭ 4.7 Hz, J ϭ 1.3 Hz, 1 H). – 13C NMR(CDCl3): δ ϭ 28.3, 30.4,
30.8, 41.2, 42.0, 52.49, 52.54, 116.7, 123.4, 125.7, 135.1, 137.3,
142.8, 146.1, 175.4. – MS (70 eV); m/z (%): 304 (37) [Mϩ], 273 (8),
246 (16), 245 (100), 218 (16), 185 (48), 169 (13), 159 (32), 145 (12). –
HRMS (C16H20N2O4): calcd. 304.1423; found 304.1417,
N-[2-(1-Cyclohexenyl)-3-pyridyl]-N-methylamine (14d): Yield: 93%,
m.p. 115–116 °C (ethyl acetate). – 1H NMR (200 MHz, CDCl3):
δ ϭ 1.68–1.90 (m, 4 H), 2.16–2.30 (m, 2 H), 2.32–2.46 (m, 2 H),
2.85 (d, J ϭ 5.1 Hz, 3 H), 4.35 (broad s, 1 H), 5.95–6.02 (m, 1 H),
6.89 (dd, J ϭ 8.1 Hz, J ϭ 1.4 Hz, 1 H), 7.08 (dd, J ϭ 8.1 Hz, J ϭ
4.8 Hz, 1 H), 7.96 (dd, J ϭ 4.8 Hz, J ϭ 1.4 Hz, 1 H). – 13C NMR
(CDCl3): δ ϭ 22.7, 23.5, 25.6, 28.4, 31.0, 116.4, 122.8, 128.4, 136.7,
137.2, 142.5, 148.5. – MS (70 eV); m/z (%): 188 (73) [Mϩ], 187 (55),
173 (15), 160 (26), 159 (100), 146 (22), 145 (50), 131 (15). – HRMS
(C12H16N2): calcd. 188.1314; found 188.1332. – C12H16N2 (188.3):
calcd. C 76.56, H 8.57, N 14.88; found C 76.50, H 8.50, N 14.65.
From Phenyl Vinyl Sulfone: After reflux for 10 min, an inseparable
mixture of N-methyl-N-{2-[5-(phenylsulfonyl)-1-cyclohexyl]-3-
m.p. 89–90 °C (ethyl acetate). – H NMR (200 MHz, CDCl3): δ ϭ pyridyl}amine (22a) and N-methyl-N-{2-[4-(phenylsulfonyl)-1-
N-[2-(1-Cycloheptenyl)-3-pyridyl]-N-methylamine (14e): Yield: 92%,
1
1.60–1.80 (m, 4 H), 1.80–1.95 (m, 2 H), 2.30–2.40 (m, 2 H), 2.50–
2.60 (m, 2 H), 2.84 (d, J ϭ 4.4 Hz, 3 H), 4.21 (broad s, 1 H), 6.15 tio 7:2 according to HPLC). – MS (70 eV); m/z (%): 328 (14) [Mϩ],
(t, J ϭ 6.4 Hz, 1 H), 6.86 (dd, J ϭ 8.1, J ϭ 1.4 Hz, 1 H), 7.04 (dd,
187 (100), 185 (95), 171 (12), 169 (11), 159 (18), 145 (22), 77 (10),
cyclohexyl]-3-pyridyl}amine (22b) formed. Yield: 52% (isomers ra-
J ϭ 8.1 Hz, J ϭ 4.7 Hz, 1 H), 7.93 (dd, J ϭ 4.7 Hz, J ϭ 1.4 Hz, 1 43 (47). – HRMS (C16H20N2O4): calcd. 328.1245; found 328.1231.
H). – 13C NMR(CDCl3): δ ϭ 27.7, 28.2, 29.5, 31.0, 32.9, 33.6,
116.5, 122.7, 134.0, 137.2, 142.2, 142.9, 150.2. – MS (70 eV); m/z
(%): 202 (47) [Mϩ], 201 (19), 187 (14), 173 (24), 160 (17), 159 (100),
146 (33), 145 (26), 131 (14). – HRMS (C13H18N2): calcd. 202.1470;
found 202.1461.
Acknowledgments
This work was supported by the State Committee for Scientific
Research Grant no. 3T09A 122 16.
N-[2-(1H-Inden-2-yl)-3-pyridyl]-N-methylamine (25): Yield: 90%
(oil). – 1H NMR (200 MHz, CDCl3): δ ϭ 2.94 (d, J ϭ 4.9 Hz, 3
H), 4.10 (s, 2 H), 4.65 (broad s, 1 H), 7.03 (dd, J ϭ 8.2 Hz, J ϭ
1.4 Hz, 1 H), 7.14 (dd, J ϭ 8.2 Hz, J ϭ 4.5 Hz, 1 H), 7.22–7.42 (m,
3 H), 7.45–7.52 (m, 1 H), 7.60–7.54 (m, 1 H), 8.10 (dd, J ϭ 4.5 Hz,
J ϭ 1.5 Hz, 1 H). – 13C NMR (CDCl3): δ ϭ 31.2, 42.3, 117.3,
121.9, 123.2, 124.3, 125.9, 127.0, 130.0, 138.2, 141.7, 143.7, 144.2,
145.5, 146.4. – MS (70 eV); m/z (%): 222 (93) [Mϩ], 221 (100), 219
(13), 207 (32), 206 (22), 205 (16). – HRMS (C15H14N2): calcd.
222.1157; found 222.1152.
[1]
K. Wojciechowski, Pol. J. Chem. 1997, 71, 1375–1400.
[2]
K. Wojciechowski, Tetrahedron 1993, 49, 7277–7286.
[3]
´
K. Wojciechowski, S. Kosinski, Tetrahedron Lett. 1997, 38,
4667–4670.
[4]
[5]
[6]
[7]
[8]
C.W. G. Fishwick, R. C. Storr, P. W. Manley, J. Chem. Soc.,
Chem. Commun. 1984, 1304–1305.
K. R. Randles, R. C. Storr, Tetrahedron Lett. 1987, 28, 5555–
5558.
L. Strekowski, A. Kiselyov, M. Hojjat, J. Org. Chem. 1994, 59,
5886–5890.
´
K. Wojciechowski, S. Kosinski, Pol. J. Chem. 1998, 72, 2546–
2550.
Thermal Extrusion of SO2 from Cyclobutanespiro-3Ј-pyridosultam
(17) in the Presence of Dienophiles. – General Procedure: Pyridosul-
K. Wojciechowski, Synth. Commun. 1997, 27, 135–144.
Eur. J. Org. Chem. 2000, 1263Ϫ1270
1269

´
S. Kosinski, K. Wojciechowski
FULL PAPER
[9]
[13]
[14]
K. Wojciechowski, Liebigs Ann. Chem. 1991, 831–832.
U. Misslitz, A. de Meijere, in Houben Weyl Methoden der Or-
ganischen Chemie, Thieme Stuttgart, 1989, vol E19b, t. 1, 723.
M.S. Baird, Topics in Current Chemistry 1987, 144, 137–209
I. Mahadevan, M. Rasmussen, J. Heterocyclic Chem. 1992, 29,
L. S. Hegedus, G. F. Allen, J. J.Bozell, E. L. Waterman, J. Am.
Chem. Soc. 1978, 100, 5800–5807.
A. Kasahara, T. Izumi, S. Murakami, K. Miyamoto, T. Hino,
J. Heterocyclic Chem. 1989, 26, 1405–1413.
[10]
[11]
[12]
Received July 20, 1999
[O99441]
359–367.
1270
Eur. J. Org. Chem. 2000, 1263Ϫ1270