Efficient One-Pot Synthesis of Dithieno(dibenzothieno)-Fused Cycloheptanones, Tropones, and Cyclooctanones

Article abstract of DOI:10.1021/jo980079e

The reactions of α,β-unsaturated amide/triflic anhydride complexes (generated in situ from the corresponding amides and triflic anhydride) with dithiophenes and dithienylmethanes proceed as tandem alkylation-Vilsmeier-Haack acylation to form dithieno- and dibenzothieno-fused cycloheptanones and cyclooctanones in moderate to good yields. The reactions of 2-bromo-N,N-dimethylacrylamide/triflic anhydride complex allow preparation of tropones in a simple one-pot procedure. The reaction of 2,2-dibenzothienylmethane with dimethylacrylamide/triflic anhydride complex proceeds unusually to afford dimethylaminonaphthalene in addition to the predictable fused cyclooctanone.

Full text of DOI:10.1021/jo980079e

6132
J . Org. Chem. 1998, 63, 6132-6136
Efficien t On e-P ot Syn th esis of Dith ien o(d iben zoth ien o)-F u sed
Cycloh ep ta n on es, Tr op on es, a n d Cycloocta n on es
Valentine G. Nenajdenko,* Ivan L. Baraznenok, and Elizabeth S. Balenkova*
Department of Chemistry, Moscow State University, Moscow 119899, Russia
Received J anuary 16, 1998
The reactions of R,â-unsaturated amide/triflic anhydride complexes (generated in situ from the
corresponding amides and triflic anhydride) with dithiophenes and dithienylmethanes proceed as
tandem alkylation-Vilsmeier-Haack acylation to form dithieno- and dibenzothieno-fused cyclo-
heptanones and cyclooctanones in moderate to good yields. The reactions of 2-bromo-N,N-
dimethylacrylamide/triflic anhydride complex allow preparation of tropones in a simple one-pot
procedure. The reaction of 2,2-dibenzothienylmethane with dimethylacrylamide/triflic anhydride
complex proceeds unusually to afford dimethylaminonaphthalene in addition to the predictable
fused cyclooctanone.
Sch em e 1
In tr od u ction
Application of triflic anhydride as a mild and effective
activation reagent in Vilsmeier-Haack reaction is a
subject of increasing interest.1-4 In our previous papers,5-8
we have reported the reaction of the N,N-dimethylacryl-
amide/triflic anhydride complex 1a with electron-rich
aromatics and heteroaromatics yielding the correspond-
ing fused cyclopentanones and/or 1,3-diaryl(dihetaryl)-
propanones.
The iminium triflates 1a -c have two electrophilic
centerssan iminium moiety and an activated double
bond. The mechanism envisioned for the reaction of 1a
involves the initial alkylation of aromatic substrate
followed by either intra- (path A) or intermolecular (path
B) Vilsmeier acylation (Scheme 1).5
Sch em e 2
In this paper we explore the possibility to realize the
third pathway for this tandem reaction. It is intramo-
lecular (like the path A) but binds two different aromatic
rings (like the path B). We suggested that the use of
appropriately substituted and activated bis-aromatic
compounds with different bridge lengths would provide
an efficient and concise route to a number of fused seven-
and eight-membered cyclic ketones. One can tune the
reaction by modifying the structure and properties of the
aromatic nuclei.
The present paper reports our investigation toward the
synthesis of dithieno-fused seven- and eight-membered
ring ketones by reaction of 1a -c with 3,3′-dithiophenes
and dibenzo[b]thiophenes.
Resu lts a n d Discu ssion
(1) Martinez, A. G.; Alvarez, R. M.; Barcina, J . O.; Cerero, S. M.;
Vilar, E. T.; Fraile, A. G.; Hanack, M.; Subramanian, L. R. J . Chem.
Soc., Chem. Commun. 1990, 1571.
(2) Maas, G.; Rahm, R.; Schletz, M.; Wurtwein, E. U. J . Org. Chem.
1994, 59, 6862.
(3) Black, D. S.; Ivory, A. J .; Kumar, N. Tetrahedron 1996, 52, 4697.
(4) Black, D. C.; Ivory, A. J .; Kumar, N. Tetrahedron 1996, 52, 7003.
(5) Nenajdenko, V. G.; Baraznenok, I. L.; Balenkova, E. S. Tetra-
hedron 1996, 52, 12993.
(6) Baraznenok, I. L.; Nenajdenko, V. G.; Balenkova, E. S. Synthesis
1997, 465.
We have found that 1a smoothly reacts with 3,3-
dithiophene (2) to give rise to the dithieno-fused cyclo-
heptanone 3a in 68% yield (Scheme 2). To study the
behavior of other R,â-unsaturated amide/triflic anhydride
complexes in seven-membered ring closure, we have
carried out the reactions of 1b and 1c with 2 and obtained
the corresponding fused cycloheptanones 3b and 3c in
moderate yields. Notably, fused ketones 3a -c have
unusual CdO absorption bands in their IR spectra at
1630-1640 cm-1 which could be explained by the influ-
ence of electron-donating sulfur atom.
(7) Baraznenok, I. L.; Nenajdenko, V. G.; Balenkova, E. S. Khim.
Geterotsikl. Soedin. 1997, 503.
(8) Nenajdenko, V. G.; Baraznenok, I. L.; Balenkova, E. S. Zh. Org.
Khim. 1998, in press.
S0022-3263(98)00079-6 CCC: $15.00 © 1998 American Chemical Society
Published on Web 08/20/1998

Synthesis of Dithieno(dibenzothieno)-Fused Cycloheptanones
J . Org. Chem., Vol. 63, No. 18, 1998 6133
Sch em e 3
prepared from the corresponding aryllithium compounds
and ethyl formate.
It was found that 10 reacts cleanly with 1a and 1c to
afford the corresponding fused cyclooctanones 11a and
11c in moderate yields (Scheme 6).
We have also studied the reaction of 12 with 1a .
Surprisingly, naphthothiophene derivative 14 was iso-
lated along with the desired eight-membered cyclic
ketone 13 (Scheme 7). The formation of 14 proceeds via
the Vilsmeier cyclization into the 4-position of the ben-
zothiophene ring followed by an acid-catalyzed isomer-
ization to the aromatic amine. In both cases the leaving
group is OTf, but iminium salt B is stable under the
reaction conditions and converts to the ketone 13 after
quenching with base whereas the benzothiophene inter-
mediate C undergoes the isomerization to the naphtha-
lene system having greater aromatic delocalization en-
ergy (Scheme 7).
Sch em e 4
To test this supposition, we have investigated the
behavior of 2-methylbenzo[b]thiophene 15 in the reaction
with complex 1a . Analogously, the product of cyclization
into the benzene ring, dimethylamine 17, was isolated
in addition to the intermolecular reaction product 16
(Scheme 8). The reaction pathway and the yield of each
product depend on the reaction conditions such as dilu-
tion and molar ratio of 15 and 1a . It was found that
yields of both 16 and 17 are in the range of 10-25%, with
the total yield 34-36%.
We have also attempted to prepare a nine-membered
cyclic ketone from 1,2-di(3-thieno)ethane 20. However,
our attempts were unsuccessful; monitoring of the reac-
tion mixture by TLC showed only formation of numerous
oligomers (Scheme 9).
We have found that 2,2-dibenzo[b]thiophene (4) reacts
with 1a similarly to produce the corresponding fused
cycloheptanone 5a in 45% yield (Scheme 3). Our at-
tempts to carry out the reaction of 4 with 1b were
unsuccessful due to the lower reactivity of 1b compared
to the reactivity of 1a .5
The reactions of 1c with 2 or 4 permit preparation of
dithieno-fused tropone 3d and dibenzo[b]thieno-fused
tropone 5d after quenching with aqueous Et3N (Schemes
2, 3). It is also possible to convert 3c to 3d quantitatively
by treatment with Et3N in CHCl3. The known literature
approach to this class of fused systems involves compli-
cated multistep synthesis with the overall yield near
1.5%.9
Tropones 3d and 5d were isolated as high-melting and
far more polar (according to the TLC data) substances
than 3a -c and 5a . This could be explained by consider-
able contribution of dipole resonance structure A (Scheme
2).
2,2-Dithiophene 6 reacts with 1a to yield only the
product of intermolecular reaction 7. However, 5,5′-
dibromo-2,2′-dithiophene 8 (easily obtained from 6 by
direct bromination with NBS10) was found to react with
1a giving rise to the cyclic ketone 9 (although in low
yields and with a considerable recovery of the starting
dibromide) (Scheme 4). Attempts to improve the yield
of 9 by the variation of solvent, stoichiometry, and
reaction time were unsuccessful.
Con clu sion
In summary, we have studied the reactions of several
R,â-unsaturated amide/triflic anhydride complexes 1a -c
with dithiophenes and dithienylmethanes. It was dem-
onstrated that dithiophene- and dibenzothiophene-fused
cycloheptanones, tropones, and cyclooctanones are easily
prepared by this method in moderate to good yields. In
addition to the expected products 2-alkyl-substituted
benzothiophenes and 2,2-dibenzothienylmethane afforded
dimethylaminonaphthalenes resulting from cyclization
into the 4-position followed by acid-catalyzed isomeriza-
tion of the benzothiophene aromatic system to the
naphthalene aromatic system.
Exp er im en ta l Section
Melting points were determined in sealed capillaries and
are uncorrected. Column chromatography was performed on
silica gel (63-200 mesh, Merck). All solvents were dried and
distilled according to the standard procedures. Triflic anhy-
dride was prepared according to the literature procedure12 from
trifluoromethanesulfonic acid (Merck). 5,5′-Dibromo-2,2′-
dithiophene was synthesized from 2,2′-dithiophene by direct
bromination with NBS10 in 85% yield. 2-Methylbenzo[b]-
thiophene and 2,2′-dibenzo[b]thiophene were synthesized from
benzo[b]thienyllithium under known procedures.13 1,2-Di(3-
thieno)ethane was prepared from 3-(bromomethyl)thiophene.14
To perform the eight-membered ring closure, two
appropriate substratess3,3-dithienylmethane (10) and
2,2-dibenzo[b]thienylmethane (12)swere synthesized and
tested under the standard reaction conditions. The
starting materials 10 and 12 were prepared by TMSI11
reduction of diarylmethanols 10a and 12a in 62% and
31% yields, respectively. In the case of 12a , a consider-
able amount of dimeric byproduct11 12b was formed
(Scheme 5). The methanols 10a and 12a were easily
(12) Stang, P. J .; Hanack, M.; Subramanian, L. R. Synthesis 1982,
85.
(9) Gronowitz, S.; Pedaja, P. Tetrahedron 1978, 34, 587.
(10) Wurthner, F.; Gotz, G.; Effenberger, F. Synthesis 1993, 1099.
(11) Stoner, E. J .; Cothron, D. A.; Balmer, M. K.; Roden, B. A.
Tetrahedron 1995, 51, 11043.
(13) Brandsma, L. Preparative Polar Organometallic Chemistry;
Springer-Verlag: Berlin, Heidelberg, 1990; Vol. 1, 2.
(14) Campaigne, E.; LeSuer, W. M. J . Am. Chem. Soc. 1948, 70,
1555.

6134 J . Org. Chem., Vol. 63, No. 18, 1998
Nenajdenko et al.
Sch em e 5
Sch em e 6
Sch em e 8
Sch em e 7
below 0 °C. The organic layer was separated, and the aqueous
layer was extracted with CHCl3 (2 × 10 mL). The combined
solutions were dried with Na2SO4 and concentrated in vacuo.
The residue was chromatographed on a short silica gel column
(benzene-ether 4:1) to yield pale-yellow viscous oils, which
solidified upon standing.
Di(3-th ien yl)m eth a n ol (10a ). Yield 87%, mp 61-62 °C.
IR (Nujol) 3480 cm-1 1H NMR (CDCl3) δ 7.19 (dd, 2H, J )
;
5.0, 3.0 Hz), 7.07 (m, 2H), 6.93 (dd, 2H, J ) 5.0, 1.3 Hz), 5.76
(s, 1H), 3.10 (br s, 1H); 13C NMR (CDCl3) δ 144.71 (2C), 126.26
(2C), 125.94 (2C), 121.50 (2C), 68.67. Anal. Calcd for C9H8-
OS2: C, 55.07; H, 4.11. Found: C, 54.85; H, 4.27.
Di(ben zo[b]th iop h en -2-yl)m eth a n ol (12a ). Yield 84%,
mp 133-136 °C. IR (Nujol) 3490 cm-1 1H NMR (CDCl3) δ
;
7.79 (d, 2H, J ) 7.8 Hz), 7.70 (d, 2H, J ) 7.8 Hz), 7.37-7.29
(m, 4H), 7.25 (s, 2H), 6.40 (s, 1H), 3.16 (br.s, 1H); 13C NMR
(CDCl3) δ 146.82 (2C), 139.79 (2C), 139.19 (2C), 124.49 (2C),
124.36 (2C), 123.77 (2C), 122.45 (2C), 121.69 (2C), 69.49. Anal.
Calcd for C17H12OS2: C, 68.89; H, 4.08. Found: C, 68.50; H,
4.00.
Red u ction of Dia r ylm eth a n ols by TMSI.11 To a well-
stirred solution of chlorotrimethylsilane (10.9 g, 100 mmol) in
anhydrous CH3CN (20 mL) was added NaI (15.0 g, 100 mmol)
in one portion. The resulting slurry was stirred for 20 min at
0 °C, and then a solution of corresponding diarylmethanol (20
mmol) in CH3CN (20 mL) was added dropwise over 30 min to
maintain the reaction temperature below 10 °C. The reaction
mixture was quenched with aqueous NaOH (3 g in 15 mL),
extracted with ethyl acetate (2 × 40 mL), washed with a
solution of Na2S2O3‚5H2O (11.2 g in 50 mL), and dried over
Na2SO4. Organic solvents were removed in vacuo, brown
residue was purified by column chromatography (hexane) to
yield the pure diarylmethanes as a white solid (12) or pale-
yellow oil which solidified upon standing (10). In the case of
12a , a considerable amount of dimeric product11 12b was
successively isolated by column chromatography.
Organolithium compounds were prepared according to the
literature techniques.13
P r ep a r a tion of Dia r ylm eth a n ols. A solution of organo-
lithium compound (60 mmol) in THF13 was cooled to -70 °C,
and a solution of the ethyl formate (30 mmol) in THF (10 mL)
was added dropwise while maintaining the temperature
between -70 and -60 °C. The mixture was then allowed to
warm slowly (over ∼1 h) to 0 °C. The resulting mixture was
hydrolyzed with 10% aq HCl (10 mL, 27 mmol) with cooling

Synthesis of Dithieno(dibenzothieno)-Fused Cycloheptanones
Sch em e 9
J . Org. Chem., Vol. 63, No. 18, 1998 6135
3-(3-Th ien ylm eth yl)th iop h en e (10). Yield 62%, mp 35-
36 °C. 1H NMR (CDCl3) δ 7.38 (m, 2H), 7.09 (m, 4H), 4.14 (s,
2H); 13C NMR (CDCl3) δ 140.75 (2C), 128.21 (2C), 125.42 (2C),
121.00 (2C), 30.89. Anal. Calcd for C9H8S2: C, 59.96; H, 4.47.
Found: C, 59.68; H, 4.26.
general procedure from 2-bromo-N,N-dimethylacrylamide (8.5
mmol), triflic anhydride (8.5 mmol), and 2 (8.5 mmol) was
poured into the aqueous Et3N (20 mmol) and stirred overnight.
The product was isolated according to general procedure. Yield
42% (66%).15 Meth od B. 3c (4 mmol) was dissolved in CHCl3
(10 mL) and then aqueous Et3N (10 mmol) was added, and
the mixture was stirred for an additional 5 h. The organic
layer was separated, dried over Na2SO4, and solvent was
removed in vacuo to afford pure 3d , yield 100%, mp 172 °C.
IR (Nujol) 1575, 1600 cm-1; 1H NMR (CDCl3) δ 7.81 (d, 1H, J
) 5.3 Hz), 7.74 (d, 1H, J ) 5.3 Hz), 7.72 (d, 1H, J ) 5.3 Hz),
7.68 (d, 1H, J ) 12.2 Hz), 7.66 (d, 1H, J ) 5.3 Hz), 6.86 (d,
1H, J ) 12.2 Hz); 13C NMR (CDCl3) δ 180.86, 147.62, 138.55,
137.68, 136.70, 134.14, 131.96, 129.75, 128.17, 128.09, 127.12.
Anal. Calcd for C11H6OS2: C, 60.53; H, 2.77. Found: C, 60.20;
H, 3.16.
2-(Ben zo[b]t h iop h en -2-ylm et h yl)b en zo[b]t h iop h en e
(12). Yield 31%, mp 134-136 °C. 1H NMR (CDCl3) δ 7.79 (d,
2H, J ) 7.8 Hz), 7.72 (d, 2H, J ) 7.8 Hz), 7.36 (dd, 2H, J )
7.8, 7.6 Hz), 7.30 (dd, 2H, J ) 7.8, 7.6 Hz), 7.18 (s, 2H), 4.51
(s, 2H); 13C NMR (CDCl3) δ 142.99 (2C), 139.83 (4C), 124.23
(2C), 123.93 (2C), 123.15 (2C), 122.20 (4C), 31.94. Anal. Calcd
for C17H12S2: C, 72.82; H, 4.31. Found: C, 72.76; H, 4.45.
2-(Ben zo[b]t h iop h en -2-ylm et h yl)-3-[d i(b en zo[b]t h io-
p h en -2-yl)m eth yl]-1-ben zo[b]th iop h en e (12b). Yield 33%,
mp 201-203 °C. 1H NMR (CDCl3) δ 7.81 (d, 1H, J ) 8.2 Hz),
7.76-7.70 (m, 3H), 7.62 (dd, 2H, J ) 7.6, 1.6 Hz), 7.56 (dd,
1H, J ) 7.6, 1.8 Hz), 7.34-7.24 (m, 9H), 7.22 (s, 2H), 7.05 (s,
1H), 6.52 (s, 1H), 4.54 (s, 2H); 13C NMR (CDCl3) δ 145.15 (2C),
142.28, 140.24, 139.82 (2C), 139.77, 139.63, 139.36 (2C),
138.74, 138.70, 131.55, 124.28 (2C), 124.20 (4C), 124.14,
123.92, 123.43(2C), 123.34, 123.27 (2C), 123.14, 122.62, 122.37,
122.17 (2C), 122.13, 41.94, 30.17. Anal. Calcd for C34H22S4:
C, 73.08; H, 3.97. Found: C, 72.79; H, 4.08.
Gen er a l P r oced u r e for Cyclic Keton e F or m a tion . A
solution of R,â-unsaturated amide (8.5 mmol) in anhydrous
C2H4Cl2 (20 mL) was cooled to 0 °C. Triflic anhydride (2.4 g,
8.5 mmol) in C2H4Cl2 (10 mL) was added dropwise over a
period of 10 min, and then the corresponding thiophene (8.5
mmol) in C2H4Cl2 (10 mL) was added. The reaction mixture
was refluxed 0.5-8 h and then was added to a mixture of Et2O
and aqueous Na2CO3 and stirred for an additional 1 h. The
organic layer was separated, and the aqueous layer was
extracted with Et2O (2 × 20 mL). The organic solvents were
removed in vacuo. The residue was purified by column
chromatography (silica gel, benzene for 3a -c, 5a , 5c, 9, 11a ,
11c, 13, 14, 16, 17; hexane/diethyl ether 4:1 for 7; benzene/
diethyl ether 3:1 for 3d , 5d ) to afford pure cyclic ketone and
some of the unreacted aromatic substrate.
6,7-Dih yd r o-5H -b en zo[b]t h ien o[3′,2′:6,7]cycloh ep t a -
[1,2-b]ben zo[b]th iop h en -5-on e (5a ). Yield 37% (74%),15 mp
1
177-179 °C. IR (Nujol) 1650 cm-1; H NMR (CDCl3) δ 8.79
(d, 1H, J ) 8.0 Hz), 7.80-7.70 (m, 3H), 7.48-7.34 (m, 4H),
3.20-3.16 (m, 2H), 3.06-3.02 (m, 2H); 13C NMR (CDCl3) δ
195.49, 146.63, 139.55, 139.53, 138.92, 137.64, 137.40, 131.83,
129.55, 126.49, 126.18, 126.17, 125.67, 124.93, 122.52, 122.46,
121.26, 42.47, 20.81. Anal. Calcd for C19H12OS2: C, 71.22;
H, 3.77. Found: C, 71.02; H, 4.01.
5H-Ben zo[b]th ien o[3′,2′:6,7]cycloh ep ta [1,2-b][1]ben zo-
th iop h en -5-on e (5d ). The reaction mixture obtained under
the general procedure from 2-bromo-N,N-dimethylacrylamide
(8.5 mmol), triflic anhydride (8.5 mmol), and 4 (8.5 mmol) was
poured into aqueous Et3N (20 mmol) and stirred overnight.
The product was isolated according to the general procedure.
Yield 39% (68%),15 mp 251-254 °C. IR (Nujol) 1585, 1615
cm-1 1H NMR (CDCl3) δ 9.29 (d, 1H, J ) 7.8 Hz), 8.05 (m,
;
1H), 7.92 (d, 1H, J ) 12.5 Hz), 7.88-7.74 (m, 2H), 7.57-7.48
(m, 3H), 7.38-7.30 (m, 1H), 7.23 (d, 1H, J ) 12.5 Hz); 13C NMR
(CDCl3) δ 183.11, 151.83, 139.51, 138.31, 138.16, 135.26,
131.71, 127.71, 127.52, 127.18, 126.68, 126.20, 125.75, 124.90,
123.70, 122.38, 122.18, 121.37, 121.12. Anal. Calcd for C19H10
OS2: C, 71.67; H, 3.17. Found: C, 71.27; H, 3.09.
-
5,6-Dih yd r o-4H-th ien o[3′,2′:3,4]cycloh ep ta [1,2-b]th io-
p h en -4-on e (3a ). Yield 68% (85%),15 mp 50-51 °C. IR (Nujol)
1
1,3-Bis[5-(2-th ien yl)-2-th ien yl]-1-p r op a n on e (7). Yield
53% (84%),15 mp 141-142 °C. IR (Nujol) 1655 cm-1; 1H NMR
(CDCl3) δ 7.60 (d, 1H, J ) 4.0 Hz), 7.33-7.30 (m, 2H), 7.16
(dd, 1H, J ) 5.1, 1.2 Hz), 7.15 (d, 1H, J ) 4.0 Hz), 7.09 (dd,
1H, J ) 3.6, 1.2 Hz), 7.05 (dd, 1H, J ) 5.0, 3.9 Hz), 6.98 (dd,
1H, J ) 5.0, 3.6 Hz), 6.97 (d, 1H, J ) 3.6 Hz), 6.80 (d, 1H, J
) 3.6 Hz), 3.26 (s, 4H); 13C NMR (CDCl3) δ 190.90, 145.74,
142.82, 141.67, 137.56, 136.23, 135.48, 132.76, 128.19, 127.65,
126.50, 125.64, 125.54, 124.12, 123.92, 123.45, 123.22, 40.48,
24.65. Anal. Calcd for C19H14OS4: C, 59.04; H, 3.65. Found:
C, 58.77; H, 3.74.
2,8-Dibr om o-5,6-dih ydr o-4H-th ien o[3′,2′:6,7]cycloh epta-
[1,2-b]th iop h en -4-on e (9). Yield 25% (78%),15 mp 136-137
°C. IR (Nujol) 1645 cm-1; 1H NMR (CDCl3) δ 7.51 (s, 1H), 6.90
(s, 1H), 2.90-2.78 (m, 4H); 13C NMR (CDCl3) δ 192.53, 143.50,
141.86, 136.12, 132.66, 132.50, 132.08, 112.97, 110.23, 41.17,
23.21. Anal. Calcd for C11H6Br2OS2: C, 34.94; H, 1.60.
Found: C, 34.79; H, 1.86.
1635 cm-1; H NMR (CDCl3) δ 7.50 (d, 1H, J ) 5.0 Hz), 7.15
(d, 1H, J ) 4.9 Hz), 7.13 (d, 1H, J ) 5.0 Hz), 6.97 (d, 1H, J )
4.9 Hz), 2.95-2.90 (m, 2H), 2.81-2.76 (m, 2H); 13C NMR
(CDCl3) δ 192.38, 140.42, 139.19, 138.12, 133.45, 132.50,
128.34, 127.46, 121.54, 40.96, 21.83. Anal. Calcd for C11H8-
OS2: C, 59.97; H, 3.66. Found: C, 59.54; H, 3.40.
5-Met h yl-5,6-d ih yd r o-4H -t h ien o[3′,2′:3,4]cycloh ep t a -
[1,2-b]th iop h en -4-on e (3b). Yield 58% (79%),15 mp 49-50
°C. IR (Nujol) 1635 cm-1; 1H NMR (CDCl3) δ 7.55 (d, 1H, J )
5.0 Hz), 7.23 (d, 2H, J ) 5.0 Hz), 7.05 (d, 1H, J ) 5.0 Hz),
3.04-3.87 (m, 3H), 1.17 (d, 3H, J ) 6.4 Hz); 13C NMR (CDCl3)
δ 195.02, 139.13, 138.75, 138.29, 133.53, 132.64, 128.30,
127.39, 121.86, 44.07, 29.37, 15.12. Anal. Calcd for C12H10
OS2: C, 61.51; H, 4.30. Found: C, 62.02; H, 4.48.
-
5-Br om o-5,6-d ih yd r o-4H -t h ien o[3′,2′:3,4]cycloh ep t a -
[1,2-b]th iop h en -4-on e (3c). Yield 42% (66%),15 mp 119-121
°C. IR (Nujol) 1630 cm-1; 1H NMR (CDCl3) δ 7.73 (d, 1H, J )
5.0 Hz), 7.36 (d, 1H, J ) 5.0 Hz), 7.34 (d, 1H, J ) 4.9 Hz),
7.22 (d, 1H, J ) 4.9 Hz), 4.88 (dd, 1H, J ) 6.8, 1.8 Hz), 3.54
6,10-Dih yd r oth ien o[3′,2′:4,5]cycloocta [1,2-b]th iop h en -
4(5H)-on e (11a ). Yield 34% (69%),15 mp 134-135 °C. IR
(dd, 1H, J ) 16.5, 1.8 Hz), 3.43 (dd, 1H, J ) 16.5, 6.8 Hz); 13
C
(Nujol) 1640 cm-1 1H NMR (CDCl3) δ 7.47 (d, 1H, J ) 4.9
;
NMR (CDCl3) δ 186.13, 139.52, 137.04, 135.84, 135.62, 133.65,
128.75, 127.82, 123.17, 50.70, 30.55. Anal. Calcd for C11H7-
BrOS2: C, 44.16; H, 2.36. Found: C, 44.70; H, 2.52.
Hz), 6.99 (d, 1H, J ) 4.9 Hz), 6.97 (d, 1H, J ) 5.0 Hz), 6.73 (d,
1H, J ) 5.0 Hz), 4.28 (s, 2H), 3.45-3.40 (m, 2H), 3.35-3.30
(m, 2H); 13C NMR (CDCl3) δ 194.36, 147.97, 140.94, 135.92,
134.48, 132.70, 131.20, 130.48, 122.00, 38.77, 30.54, 25.66.
Anal. Calcd for C12H10OS2: C, 61.51; H, 4.30. Found: C,
60.97; H, 4.18.
4H -Th ien o[3′,2′:3,4]cycloh ep t a [1,2-b]t h iop h en -4-on e
(3d ). Meth od A. The reaction mixture obtained under the
(15) Yield based on conversion of substrate.

6136 J . Org. Chem., Vol. 63, No. 18, 1998
Nenajdenko et al.
5-Br om o-6,10-d ih yd r oth ien o[3′,2′:4,5]cycloocta [1,2-b]-
th iop h en -4(5H)-on e (11c). Yield 31% (61%),15 mp 163-164
isolated according to the general procedure to give 16 as a
white solid, yield 25%, mp 97-98 °C, and 17 as an yellow oil,
yield 10%. Meth od B. Reaction mixture obtained under the
general procedure from N,N-dimethylacrylamide (4.2 mmol),
triflic anhydride (4.2 mmol) and 15 (3.5 mmol) in C2H4Cl2 (150
mL) was quenched by aqueous Na2CO3. Products were
isolated according to general procedure to give 16 in 11% yield
°C (dec). IR (Nujol) 1655 cm-1 1H NMR (CDCl3) δ 7.52 (d,
;
1H, J ) 4.8 Hz), 7.10 (m, 2H), 6.73 (d, 1H, J ) 5.2 Hz), 5.79
(dd, 1H, J ) 12.0, 6.0), 4.31 (d, 1H, J ) 16.0 Hz), 4.10 (d, 1H,
J ) 16.0 Hz), 3.79-3.67 (m, 2H); 13C NMR (CDCl3) δ 188.82,
146.63, 137.68, 136.35, 133.36, 132.95, 130.76, 130.14, 123.25,
50.19, 36.09, 31.25. Anal. Calcd for C12H9BrOS2: C, 46.02;
H, 2.90. Found: C, 47.28; H, 3.15.
1
and 17 in 23% yield. IR (Nujol) 1670 cm-1; H NMR (CDCl3)
δ 8.09 (d, 1H, J ) 8.2 Hz), 7.82 (d, 1H, J ) 7.9 Hz), 7.78 (d,
1H, J ) 7.7 Hz), 7.70 (d, 1H, J ) 7.9 Hz), 7.43-7.31 (m, 4H),
3.38-3.33 (m, 2H), 3.30-3.25 (m, 2H), 2.72 (s, 3H), 2.60 (s,
3H); 13C NMR (CDCl3) δ 198.02, 148.26, 139.90, 138.42, 138.18,
137.34, 135.19, 132.87, 130.22, 125.17, 124.40, 123.99, 123.63,
123.47, 122.21, 121.71, 120.90, 43.16, 20.79, 16.84, 13.84.
Anal. Calcd for C20H14OS2: C, 71.96; H, 4.56. Found: C,
71.61; H, 4.82.
N,N-Dim eth yl-N-(2-m eth yl-5a ,8b-d ih yd r o-2H-n a p h th o-
[1,8-bc]th iop h en -5-yl)a m in e (17). 1H NMR (CDCl3) δ 7.66
(d, 1H, J ) 8.4 Hz, CH-8), 7.33 (dd, 1H, J ) 8.4 Hz, CH-7),
7.17 (dd, 1H, J ) 7.7, 1.4 Hz, CH-3), 7.15 (d, 1H, J ) 8.4 Hz,
CH-6), 6.98 (d, 1H, J ) 7.7 Hz, CH-4), 5.11 (dq, 1H, J ) 6.8,
1.4 Hz, CH-2), 2.88 (s, 6H, N(CH3)2), 1.71 (d, 3H, J ) 6.8 Hz,
CH3); 13C NMR (CDCl3) δ 148.68 (C-5), 143.42, 140.88, 136.10,
127.72, 127.20, 119.75, 117.77, 116.12, 114.73, 48.75 (C-2),
44.88 (N(CH3)2), 24.44 (CH3). Anal. Calcd for C14H15NS: C,
73.32; H, 6.11. Found: C, 72.95; H, 6.15.
7,13-Dih yd r oben zo[b]th ien o[3′,2′:6,7]cycloocta [1,2-b]-
ben zo[b]th iop h en -5(6H)-on e (13). Yield 17%, mp 212-215
°C (dec). IR (Nujol) 1645 cm-1 1H NMR (CDCl3) δ 8.53 (d,
;
1H, J ) 8.2 Hz), 7.73 (dd, 2H, J ) 8.2, 7.6 Hz), 7.62 (d, 1H, J
) 7.6 Hz), 7.43 (ddd, 1H, J ) 8.2, 7.2, 1.2 Hz), 7.38-7.28 (m,
3H), 4.70 (s, 2H), 3.59-3.55 (m, 2H), 3.40-3.35 (m, 2H); 13C
NMR (CDCl3) δ 197.74, 153.31, 144.49, 140.90, 138.98, 137.31,
136.80, 133.98, 129.24, 125.80, 125.24, 125.14, 124.55, 124.29,
121.97, 121.41, 121.16, 39.85, 30.07, 24.94. Anal. Calcd for
C
20H14OS2: C, 71.83; H, 4.22. Found: C, 71.35; H, 4.07.
N-[2-(Ben zo[b]t h iop h en -2-ylm et h yl)-2H -n a p h t h o[1,8-
bc]th iop h en -5-yl]-N,N-d im eth yla m in e (14). Yield 19%, mp
115-117 °C. 1H NMR (CDCl3) δ 7.78 (d, 1H, J ) 7.6 Hz), 7.33
(m, 2H), 7.36-7.25 (m, 4H), 7.18 (s, 1H, CH-), 7.15 (d, 1H, J
) 8.0 Hz), 6.97 (d, 1H, J ) 7.6 Hz, CH-4), 5.43 (dd, 1H, J )
9.2, 5.2 Hz, CH-2), 3.66 (dd, 1H, J ) 15.2, 5.2 Hz, CH2), 3.44
(dd, 1H, J ) 15.2, 9.2 Hz, CH2), 2.90 (s, 6H, N(CH3)2); 13C NMR
(CDCl3) δ 148.21 (C-5), 143.95, 142.08, 139.81, 139.74, 137.84,
136.47, 127.79, 127.17, 124.25, 123.90, 123.15, 122.74, 122.23,
120.68, 117.99, 116.38, 114.60, 55.37 (C-2), 44.84 (N(CH3)2),
40.62 (CH2). Anal. Calcd for C22H19NS2: C, 73.09; H, 5.30.
Found: C, 73.43; H, 5.55.
1,3-Bis(2-m et h ylb en zo[b]t h iop h en -3-yl)-1-p r op a n on e
(16). Meth od A. The reaction mixture obtained under the
general procedure from N,N-dimethylacrylamide (4.2 mmol),
triflic anhydride (4.2 mmol), and 15 (8.5 mmol) in C2H4Cl2 (20
mL) was quenched by aqueous Na2CO3. Products were
Ack n ow led gm en t. The research described in this
publication was partially supported by the Russian
Fundamental Investigation Foundation (Grant N 97-
03-33006a). I.B. also thanks the CHEVRON company
as well as the International Soros Science Education
Program and the Moscow Government (Grant No. a97-
23) for financial support.
J O980079E