Derivatives of the [1,2]Dithiolo[1,4]thiazine Ring System
631.0133. Anal. Calcd for C24H25NO9S5: C, 45.63; H, 3.99; N,
2.22. Found: C, 45.38; H, 3.76; N, 2.14.
(15 mg, 0.031 mmol) in dichloromethane (2 mL), and the
resulting solution was stirred at room temperature for 15 min
and worked up as before. Flash chromatography (silica gel 60,
CH2Cl2-petroleum ether 1:1) gave 5a (24 mg, 82%): 1H NMR
(CDCl3, 400 MHz) δ 3.94 (s, 3H, CH3), 3.92 (s, 3 H, CH3), 3.51
4-Eth yl-5-spir o(4,5-dicyan o-1,3-dith iol-2-yl)-6,7-dicyan o-
[1,2]dith iolo[4,3-b]th iopyr an o[2′,3′-d]pyr r ol-3-on e 2c. DCA
(36 mg, 0.474 mmol) was added to a solution of bis[1,2]-
dithiolopyrrole 1 (55 mg, 0.189 mmol) in benzene (10 mL) and
the resulting solution was stirred under reflux for 2 h and
worked up as for 2a . MPLC (silica gel 60, petroleum ether to
1
(six signals, double quartet, J ) 14.4 Hz, J ) 7.2 Hz, 1H, /2-
CH2), 3.25 (six signals, double quartet, J ) 14.4 Hz, J ) 7.2
Hz, 1H, 1/2CH2), 1.22 (t, J ) 7.2 Hz, 3H, CH3); 13C NMR (CDCl3,
100 MHz) δ 192.4 (CdS), 184.8 (CdO), 161.2 (CdO), 159.6 (Cd
O), 159.4, 153.3, 134.5, 133.0, 132.2, and 132.1 (6 × sp2 tertiary
C), 53.9 and 53.8 (2 × CH3), 47.9 (CH2), 13.4 (CH3); IR (KBr,
cm-1) ν 1753 (CdO), 1714 (CdO), 1668 (CdO), 1436, 1295 (Cd
S), 1235, 710; MS (EI) m/z 465 (M+, 38), 436 (M - 29, 100),
376 (5), 332 (8), 274 (38), 262 (8), 218 (8), 174 (12), 158 (15),
126 (40); HRMS, M+ ) 464.8961 C14H11NO5S6 requires
464.8962. Anal. Calcd for C14H11NO5S6: C, 36.12; H, 2.38; N,
3.01. Found: C, 36.12; H, 2.15; N, 2.93.
CH2Cl2-ethyl acetate 90:10) gave 2c, yellow solid (CH2Cl2-
-
petroleum ether) (31 mg, 38%), mp 228-229 °C. The low
solubility of 2c in common solvents and its slow decomposition
upon standing in solution precluded the acquisition of its 13C
NMR spectrum: 1H NMR (CDCl3, 400 MHz) δ 4.71 (q, J ) 7.0
Hz, 2H, CH2), 1.60 (t, J ) 7.0 Hz, 3H, CH3); IR (KBr, cm-1) ν
2222 (CtN), 1662 (CdO), 1530, 1063, 914; MS (EI) m/z 443
(M+, 32), 428 (M - 15, 14), 414 (M - 29, 12), 383 (M - 60,
11), 353 (12), 335 (90), 320 (27), 307 (38), 291 (12), 276 (35),
140 (22), 76 (14), 70 (SCCN+, 100); HRMS, M+ ) 442.9098
3-Oxo-4-eth yl-5-(4,5-d icya n o-1,3-d ith iol-2-ylid en yl)[1,2]-
d ith iolo[3,4-b][1,4]th ia zin e-6-th ion e 5b. DCA (30 mg, 0.39
mmol) was added to a solution of bis[1,2]dithiolo[1,4]thiazine
4 (50 mg, 0.15 mmol) in benzene (10 mL), and the resulting
solution was stirred under reflux for 10 min and worked up
as for 2a . MPLC (silica gel 60, petroleum ether to CH2Cl2) gave
5b: red solid (CH2Cl2-petroleum ether) (42 mg, 68%); mp 173-
175 °C; 1H NMR (CDCl3, 400 MHz) δ 3.60 (six signals, double
quartet, J ) 14.2 Hz, J ) 7.1 Hz, 1H, 1/2CH2), 3.21 (six signals,
C
16H5N5OS5 requires 442.9083.
4-E t h yl-5-sp ir o(4,5-d ib en zoyl-1,3-d it h iol-2-yl)-6,7-d i-
ben zoyl[1,2]dith iolo[4,3-b]th iopyr an o[2′,3′-d]pyr r ol-3-on e
2d . DBA (201 mg, 0.860 mmol) was added to a solution of bis-
[1,2]dithiolopyrrole 1 (100 mg, 0.344 mmol) in benzene (10
mL), and the resulting solution was stirred under reflux for
30 min and worked up as for 2a . MPLC (silica gel 60,
petroleum ether to CH2Cl2) gave 2d : yellow solid (CH2Cl2-
-
1
petroleum ether) (191 mg, 73%); mp 242-244 °C; 1H NMR
(CDCl3, 400 MHz) δ 7.71-7.19 (m, 20H, 4‚C6H5), 5.00 (q, J )
6.9 Hz, 2H, CH2), 1.73 (t, J ) 6.9 Hz, 3H, CH3); 13C NMR
(CDCl3, 100 MHz) δ 193.2 (CdO), 191.2 (CdO), 186.6 (CdO),
179.3 (CdO), 138.8, 137.0, 136.1, 135.7, and 135.2 (5 × sp2
tertiary C), 134.7, 133.8, and 133.5 (3 × CH aromatic, DEPT),
132.2 and 131.1 (2 × sp2 tertiary C), 130.5 and 130.3 (2 × CH
aromatic, DEPT), 129.7 and 129.3 (2 × sp2 tertiary C), 128.9,
128.5 and 128.4 (3 × CH aromatic, DEPT), 104.7 (sp2 tertiary
C), 63.3 (quaternary C), 43.0 (CH2, DEPT), 16.1 (CH3, DEPT);
IR (KBr, cm-1) ν 1660 (CdO), 1594, 1529, 1446, 1244, 689;
MS (FAB+) m/z 760 (M+ + 1, 10), 654 (M+ - 105, 1), 494 (2),
462 (3), 434 (3), 290 (38), 105 (PhCO+, 43). Anal. Calcd for
double quartet, J ) 14.2 Hz, J ) 7.1 Hz, 1H, /2CH2), 1.23 (t,
J ) 7.1 Hz, 3H, CH3); 13C NMR (CDCl3, 100 MHz) δ 196.6
(CdS), 184.4 (CdO), 154.3, 151.9, 133.8, and 131.8 (4 × sp2
tertiary C), 119.8 (CtN), 118.9 (CtN), 108.8 and 108.3 (2 ×
sp2 tertiary C), 48.2 (CH2, DEPT), 13.4 (CH3, DEPT); IR (KBr,
cm-1) ν 2925, 2240 (CtN), 1667 (CdO), 1640 (CdO), 1364,
1305 (CdS), 1000, 710; MS (EI) m/z 399 (M+, 40), 370 (M -
29, 100), 310 (5), 266. (17), 234 (11), 208 (27), 76 (14), 70 (18);
HRMS, M+ ) 398.8750 C12H5N3OS6 requires 398.8757. Anal.
Calcd for C12H5N3OS6: C, 36.07; H, 1.26; N, 10.52. Found: C,
36.00; H, 1.36; N, 10.48.
3-Oxo-4-eth yl-5-(4,5-d iben zoyl-1,3-d ith iol-2-ylid en yl)-
[1,2]dith iolo[3,4-b][1,4]th iazin e-6-th ion e 5c. Th er m al P r o-
ced u r e. DBA (24 mg, 0.10 mmol) was added to a solution of
bis[1,2]dithiolo[1,4]thiazine 4 (30 mg, 0.09 mmol) in benzene
(10 mL) and the resulting solution was stirred under reflux
for 5 min and worked up as for 2a . MPLC (silica gel 60,
petroleum ether to CH2Cl2-ethyl acetate 90:10) gave 5c: red
solid (CH2Cl2-petroleum ether) (25 mg, 48%); mp 78-79 °C.
C
40H25NO5S5: C, 63.22; H, 3.32; N, 1.84. Found: C, 63.33; H,
3.39; N, 1.82.
Dim et h yl 3-Oxo-4-et h yl-5-(1,3-d it h iol-2-ylid en yl)-6-
t h ioxo[1,2]d it h iolo[4,3-b]p yr r ole-4′,5′-d ica r b oxyla t e 3:
DMAD (24 mg, 0.17 mmol) was added to a solution of 1 (50
mg, 0.17 mmol) and Sc(OTf)3 (42 mg, 0.085 mmol) in dichlo-
romethane (5 mL) and the resulting solution was stirred under
reflux in a warm water bath for 2 h. Workup was performed
under protection against direct sunlight irradiation. The
solvent was removed in the rotatory evaporator. Preparative
TLC (silica gel 60, CH2Cl2-petroleum ether 1:1) of the resulting
solid gave 3 (17 mg, 23%), mp 116-117 °C (dec). 1H NMR
(CDCl3, 400 MHz) δ 4.64 (q, J ) 7.2 Hz, 2H, CH2), 4.01 (s, 3H,
OCH3), 4.00 (s, 3H, OCH3), 1.36 (t, J ) 7.2 Hz, 3H, CH3); 13C
NMR (CDCl3, 100 MHz) δ 210.8 (CdS), 183.5 (CdO), 159.7
and 158.7 (2 × CdO), 146.2, 144.4, 139.9, 139.6, 133.5, and
131.2 (6 × sp2 tertiary C), 56.0 and 54.2 (2 × CH3), 41.5 (CH2),
16.5 (CH3); UV (CH2Cl2, 2.3 × 10-4 M), λmax (ꢀ) 616 (818), 441
(1598), 383 (2122), 275 (5646); IR (KBr, cm-1) ν 1731 (CdO),
1716 (CdO), 1658 (CdO), 1434, 1260 (CdS), 1148, 1093, 1069,
801; MS (EI) m/z 433 (M+, 100), 291 (M - 141, 76), 286 (9),
207 (5); HRMS, M+ ) 432.9241 C14H11NO5S5 requires 432.9241.
Dim et h yl 3-Oxo-4-et h yl-5-(1,3-d it h iol-2-ylid en yl)-6-
t h ioxo[1,2]d it h iolo[3,4-b][1,4]t h ia zin e-4′,5′-d ica r b oxy-
la te 5a . Th er m a l P r oced u r e. DMAD (57 µL, 66 mg, 0.462
mmol) was added to a solution of bis[1,2]dithiolo[1,4]thiazine
4 (60 mg, 0.186 mmol) in benzene (5 mL) and the resulting
solution was stirred under reflux for 10 min and worked up
as for 2a . MPLC (silica gel 60, petroleum ether to CH2Cl2) gave
5a : red solid (CH2Cl2-petroleum ether) (70 mg, 81%); mp
159-160 °C.
Ca ta lyzed P r oced u r e. DBA (40 mg, 0.17 mmol) was added
to a solution of bis[1,2]dithiolo[1,4]thiazine 4 (55 mg, 0.17
mmol) and Sc(OTf)3 (21 mg, 0.043 mmol) in dichloromethane
(2 mL); the resulting solution was stirred at room temperature
for 5 min and worked up as before. Flash chromatography
(silica gel 60, CH2Cl2-petroleum ether 1:1) gave 5c (61 mg,
63%): 1H NMR (CDCl3, 400 MHz) δ 7.50-7.44 (m, 5H, C6H5),
7.29-7.22 (m, 5H, C6H5), 3.59 (six signals, double quartet, J
1
) 14.2 Hz, J ) 7.1 Hz, 1H, /2CH2), 3.34 (six signals, double
1
quartet, J ) 14.2 Hz, J ) 7.1 Hz, 1H, /2CH2), 1.27 (t, J ) 7.1
Hz, 3H, CH3); 13C NMR (CDCl3, 100 MHz) δ 192.3 (C)S), 186.7
(CdO), 184.7 (CdO), 161.6, 153.1, 141.6, 140.3, 136.7, and
136.4 (6 × sp2 tertiary C), 134.3, 134.2, 134.0, and 133.9 (4 ×
CH aromatic, DEPT), 132.2 and 132.0 (2 × sp2 tertiary C),
128.9 and 128.7 (2 × CH aromatic, DEPT), 48.6 (CH2, DEPT),
13.5 (CH3, DEPT); IR (KBr, cm-1) ν 2960, 2923, 1657 (CdO),
1597, 1448, 1261 (CdS), 1049, 695; MS (EI) m/z 557 (M+, 12),
542 (M - 15, 4), 528 (M - 29, 33), 513 (M - 44, 8), 501 (M -
56, 3), 452 (M - 105, 3), 351 (12), 162 (14), 105 (PhCO+, 100),
77 (Ph+, 58); HRMS, M+ ) 556.9376 C24H15NO3S6 requires
556.9282. Anal. Calcd for C24H15NO3S6: C, 51.68; H, 2.71; N,
2.51. Found: C, 51.75; H, 2.88; N, 2.74.
4-E t h yl-5-sp ir o(4,5-d ib en zoyl-1,3-d it h iol-2-yl)-6,7-d i-
b e n zo y l[1,2]d it h io lo [4,3-b ]t h io p y r a n o [2′,3′-d ][1,4]-
th ia zin -3-on e 6a . DBA (54 mg, 0.23 mmol) was added to a
solution of bis[1,2]dithiolo[1,4]thiazine 4 (30 mg, 0.09 mmol)
in benzene (10 mL), and the resulting solution was stirred
Ca ta lyzed P r oced u r e. DMAD (19 µL, 22 mg, 0.15 mmol)
was added to a solution of 4 (20 mg, 0.062 mmol) and Sc(OTf)3
J . Org. Chem, Vol. 67, No. 18, 2002 6445